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Discussion Groups | MSP430 | Can MSP430 be power off completely?
The purpose of this group is to foster exchange of information on the Texas Instruments MSP430 family of microcontrollers and related tools. Everyone welcome, all levels of familiarity/expertise.
Can MSP430 be power off completely? - =?UTF-8?B?5ZC05oup5rez?= - Sep 24 4:48:48 2009
Hello all:
I want to power off MSP430 completely when the battery is lower than a given
value, now I am using __low_power_mode_4() intrinsic command, but some
external IEs are active also. I know I can disable this IEs by some extra
code, but dose any one know some easy ways to power it of?
--
Best Regards.
Chernwu
[Non-text portions of this message have been removed]
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
I want to power off MSP430 completely when the battery is lower than a given
value, now I am using __low_power_mode_4() intrinsic command, but some
external IEs are active also. I know I can disable this IEs by some extra
code, but dose any one know some easy ways to power it of?
--
Best Regards.
Chernwu
[Non-text portions of this message have been removed]
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Can MSP430 be power off completely? - aschuh - Sep 24 7:03:11 2009
The easiest way is to clear the GIE Bit. But in this case only a POR or a P=
UC will reactivate the MSP430.
--- In m...@yahoogroups.com, =E5=90=B4=E6=8B=A9=E6=B7=B3
ote:
>
> Hello all:
>=20
> I want to power off MSP430 completely when the battery is lower than a gi=
ven
> value, now I am using __low_power_mode_4() intrinsic command, but some
> external IEs are active also. I know I can disable this IEs by some extra
> code, but dose any one know some easy ways to power it of?
>=20
> --=20
> Best Regards.
> Chernwu
>=20
>=20
> [Non-text portions of this message have been removed]
>
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
RE: Can MSP430 be power off completely? - "Jitendra Chauhan, Noida" - Sep 24 10:18:57 2009
HI,
I hope following tables helps. This is from SLAU208d page 29.
[cid:image003.png@01CA3D47.64CDC620]
Best regards,
Jitendra
From: m...@yahoogroups.com [mailto:m...@yahoogroups.com] On Behalf Of ???
Sent: Thursday, September 24, 2009 2:18 PM
To: msp430
Subject: [msp430] Can MSP430 be power off completely?
Hello all:
I want to power off MSP430 completely when the battery is lower than a given
value, now I am using __low_power_mode_4() intrinsic command, but some
external IEs are active also. I know I can disable this IEs by some extra
code, but dose any one know some easy ways to power it of?
--
Best Regards.
Chernwu
[Non-text portions of this message have been removed]
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Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of
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received this email in error please delete it and notify the sender immediately. Before opening any mail and
attachments please check them for viruses and defect.
-----------------------------------------------------------------------------------------------------------------------
[Non-text portions of this message have been removed]
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
I hope following tables helps. This is from SLAU208d page 29.
[cid:image003.png@01CA3D47.64CDC620]
Best regards,
Jitendra
From: m...@yahoogroups.com [mailto:m...@yahoogroups.com] On Behalf Of ???
Sent: Thursday, September 24, 2009 2:18 PM
To: msp430
Subject: [msp430] Can MSP430 be power off completely?
Hello all:
I want to power off MSP430 completely when the battery is lower than a given
value, now I am using __low_power_mode_4() intrinsic command, but some
external IEs are active also. I know I can disable this IEs by some extra
code, but dose any one know some easy ways to power it of?
--
Best Regards.
Chernwu
[Non-text portions of this message have been removed]
DISCLAIMER:
-----------------------------------------------------------------------------------------------------------------------
The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only.
It shall not attach any liability on the originator or HCL or its affiliates. Any views or opinions presented in
this email are solely those of the author and may not necessarily reflect the opinions of HCL or its affiliates.
Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of
this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have
received this email in error please delete it and notify the sender immediately. Before opening any mail and
attachments please check them for viruses and defect.
-----------------------------------------------------------------------------------------------------------------------
[Non-text portions of this message have been removed]
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Can MSP430 be power off completely? - Michael - Sep 24 15:37:11 2009
Chernwu,
What do you mean by 'external IEs'?
LPM4 will probably consume far less than the battery self-discharge, so LPM=
4 is probably a very good solution.
If you want to completely shut off the MSP, you can use a voltage regulator=
with an enable pin like the TPS77001 or use a series fet.
Your solution will greatly depend on how you intend to wake up the MSP afte=
r you 'turned it off'. In turn, this will depend on how the battery will be=
handled after the discharge condition (replace, in-circuit charging, DC in=
put feeding the MSP while separately charging the battery, upon many others=
).
Regards,
Michael K.
--- In m...@yahoogroups.com, =E5�=B4=E6�=A9=E6=B7=B3
>
> Hello all:
>=20
> I want to power off MSP430 completely when the battery is lower than a gi=
ven
> value, now I am using __low_power_mode_4() intrinsic command, but some
> external IEs are active also. I know I can disable this IEs by some extra
> code, but dose any one know some easy ways to power it of?
>=20
> --=20
> Best Regards.
> Chernwu
>=20
>=20
> [Non-text portions of this message have been removed]
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
What do you mean by 'external IEs'?
LPM4 will probably consume far less than the battery self-discharge, so LPM=
4 is probably a very good solution.
If you want to completely shut off the MSP, you can use a voltage regulator=
with an enable pin like the TPS77001 or use a series fet.
Your solution will greatly depend on how you intend to wake up the MSP afte=
r you 'turned it off'. In turn, this will depend on how the battery will be=
handled after the discharge condition (replace, in-circuit charging, DC in=
put feeding the MSP while separately charging the battery, upon many others=
).
Regards,
Michael K.
--- In m...@yahoogroups.com, =E5�=B4=E6�=A9=E6=B7=B3
>
> Hello all:
>=20
> I want to power off MSP430 completely when the battery is lower than a gi=
ven
> value, now I am using __low_power_mode_4() intrinsic command, but some
> external IEs are active also. I know I can disable this IEs by some extra
> code, but dose any one know some easy ways to power it of?
>=20
> --=20
> Best Regards.
> Chernwu
>=20
>=20
> [Non-text portions of this message have been removed]
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Can MSP430 be power off completely? - old_cow_yellow - Sep 24 16:23:18 2009
I think the OP did not want it to wake up at all.
What is "power off completely"? Even LPM5 is not without power.
--- In m...@yahoogroups.com, "Michael" wrote:
>
> Chernwu,
> What do you mean by 'external IEs'?
>=20
> LPM4 will probably consume far less than the battery self-discharge, so L=
PM4 is probably a very good solution.
>=20
> If you want to completely shut off the MSP, you can use a voltage regulat=
or with an enable pin like the TPS77001 or use a series fet.
>=20
> Your solution will greatly depend on how you intend to wake up the MSP af=
ter you 'turned it off'. In turn, this will depend on how the battery will =
be handled after the discharge condition (replace, in-circuit charging, DC =
input feeding the MSP while separately charging the battery, upon many othe=
rs).
>=20
> Regards,
> Michael K.
>=20
> --- In m...@yahoogroups.com, =E5�=B4=E6�=A9=E6=B7=B3
> >
> > Hello all:
> >=20
> > I want to power off MSP430 completely when the battery is lower than a =
given
> > value, now I am using __low_power_mode_4() intrinsic command, but some
> > external IEs are active also. I know I can disable this IEs by some ext=
ra
> > code, but dose any one know some easy ways to power it of?
> >=20
> > --=20
> > Best Regards.
> > Chernwu
> >=20
> >=20
> > [Non-text portions of this message have been removed]
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
What is "power off completely"? Even LPM5 is not without power.
--- In m...@yahoogroups.com, "Michael"
>
> Chernwu,
> What do you mean by 'external IEs'?
>=20
> LPM4 will probably consume far less than the battery self-discharge, so L=
PM4 is probably a very good solution.
>=20
> If you want to completely shut off the MSP, you can use a voltage regulat=
or with an enable pin like the TPS77001 or use a series fet.
>=20
> Your solution will greatly depend on how you intend to wake up the MSP af=
ter you 'turned it off'. In turn, this will depend on how the battery will =
be handled after the discharge condition (replace, in-circuit charging, DC =
input feeding the MSP while separately charging the battery, upon many othe=
rs).
>=20
> Regards,
> Michael K.
>=20
> --- In m...@yahoogroups.com, =E5�=B4=E6�=A9=E6=B7=B3
> >
> > Hello all:
> >=20
> > I want to power off MSP430 completely when the battery is lower than a =
given
> > value, now I am using __low_power_mode_4() intrinsic command, but some
> > external IEs are active also. I know I can disable this IEs by some ext=
ra
> > code, but dose any one know some easy ways to power it of?
> >=20
> > --=20
> > Best Regards.
> > Chernwu
> >=20
> >=20
> > [Non-text portions of this message have been removed]
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - OneStone - Sep 24 16:29:34 2009
A simple method of doing this is to use a solid state switch with a
momentary push button to power on the circuit, that is activated through
one diode of a BAV70, the other diode is controlled from the MSP. When
the button is pushed the MSP establishes the hold in signal to maintain
power to the circuit, when you want to turn everything off the micro
drops the signal. Depending on what else is around a weak pull down may
also be necessary
Al
old_cow_yellow wrote:
> I think the OP did not want it to wake up at all.
>
> What is "power off completely"? Even LPM5 is not without power.
>
> --- In m...@yahoogroups.com, "Michael" wrote:
>> Chernwu,
>> What do you mean by 'external IEs'?
>>
>> LPM4 will probably consume far less than the battery self-discharge, so LPM4 is probably a very good solution.
>>
>> If you want to completely shut off the MSP, you can use a voltage regulator with an enable pin like the TPS77001 or use a series fet.
>>
>> Your solution will greatly depend on how you intend to wake up the MSP after you 'turned it off'. In turn, this will depend on how the battery will be handled after the discharge condition (replace, in-circuit charging, DC input feeding the MSP while separately charging the battery, upon many others).
>>
>> Regards,
>> Michael K.
>>
>> --- In m...@yahoogroups.com, ��淳 wrote:
>>> Hello all:
>>>
>>> I want to power off MSP430 completely when the battery is lower than a given
>>> value, now I am using __low_power_mode_4() intrinsic command, but some
>>> external IEs are active also. I know I can disable this IEs by some extra
>>> code, but dose any one know some easy ways to power it of?
>>>
>>> --
>>> Best Regards.
>>> Chernwu
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
> ------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
momentary push button to power on the circuit, that is activated through
one diode of a BAV70, the other diode is controlled from the MSP. When
the button is pushed the MSP establishes the hold in signal to maintain
power to the circuit, when you want to turn everything off the micro
drops the signal. Depending on what else is around a weak pull down may
also be necessary
Al
old_cow_yellow wrote:
> I think the OP did not want it to wake up at all.
>
> What is "power off completely"? Even LPM5 is not without power.
>
> --- In m...@yahoogroups.com, "Michael"
>> Chernwu,
>> What do you mean by 'external IEs'?
>>
>> LPM4 will probably consume far less than the battery self-discharge, so LPM4 is probably a very good solution.
>>
>> If you want to completely shut off the MSP, you can use a voltage regulator with an enable pin like the TPS77001 or use a series fet.
>>
>> Your solution will greatly depend on how you intend to wake up the MSP after you 'turned it off'. In turn, this will depend on how the battery will be handled after the discharge condition (replace, in-circuit charging, DC input feeding the MSP while separately charging the battery, upon many others).
>>
>> Regards,
>> Michael K.
>>
>> --- In m...@yahoogroups.com, ��淳
>>> Hello all:
>>>
>>> I want to power off MSP430 completely when the battery is lower than a given
>>> value, now I am using __low_power_mode_4() intrinsic command, but some
>>> external IEs are active also. I know I can disable this IEs by some extra
>>> code, but dose any one know some easy ways to power it of?
>>>
>>> --
>>> Best Regards.
>>> Chernwu
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
> ------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - Augusto Einsfeldt - Sep 24 17:07:37 2009
=20
Al, as you know turning off a low power device such as MSP430 is not
an easy thing for who doesn't know much about hardware, and it seems
to be the case of this OP.
Any capacitor after the switch can hold the MSP running long enough
to allow the CPU to turn the switch ON again in case it goes to RESET
before the voltage is depleted enough. Of course it also depends on
the software, a failed SVS processing scheme, MSP430 model (without
SVS), consumption curve, etc.
The trick is to avoid any kind of extra reset after the software has
decided to go off.
One solution would be to switch off the power AND, at same time,
turn some output on to drain as many current as possible from
decoupling and bypass capacitors around MSP430.
MSP430 needs so low power to work that I would not be surprised if
one could make it run with energy harvested from a radio antenna or
even a finger touch...
-Augusto
On Qui 24/09/09 17:28 , OneStone o...@bigpond.net.au sent:
A simple method of doing this is to use a solid state switch with a=20
momentary push button to power on the circuit, that is activated
through=20
one diode of a BAV70, the other diode is controlled from the MSP.
When=20
the button is pushed the MSP establishes the hold in signal to
maintain=20
power to the circuit, when you want to turn everything off the micro
drops the signal. Depending on what else is around a weak pull down
may=20
also be necessary
Al
old_cow_yellow wrote:
> I think the OP did not want it to wake up at all.
>=20
> What is "power off completely"? Even LPM5 is not without power.
>=20
> --- In m...@yahoogroups.com, "Michael" wrote:
>> Chernwu,
>> What do you mean by 'external IEs'?
>>
>> LPM4 will probably consume far less than the battery
self-discharge, so LPM4 is probably a very good solution.
>>
>> If you want to completely shut off the MSP, you can use a voltage
regulator with an enable pin like the TPS77001 or use a series fet.
>>
>> Your solution will greatly depend on how you intend to wake up
the MSP after you 'turned it off'. In turn, this will depend on how
the battery will be handled after the discharge condition (replace,
in-circuit charging, DC input feeding the MSP while separately
charging the battery, upon many others).
>>
>> Regards,
>> Michael K.
>>
>> --- In m...@yahoogroups.com, =C3=A5=EF=BF=BD=C2=B4=C3=A6=EF=BF=BD=C2=
=A9=C3=A6=C2=B7=C2=B3 wrote:
>>> Hello all:
>>>
>>> I want to power off MSP430 completely when the battery is lower
than a given
>>> value, now I am using __low_power_mode_4() intrinsic command,
but some
>>> external IEs are active also. I know I can disable this IEs by
some extra
>>> code, but dose any one know some easy ways to power it of?
>>>
>>> --=20
>>> Best Regards.
>>> Chernwu
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
>=20
>=20
>=20
>=20
> ------------------------------------
>=20
>
>=20
>
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Al, as you know turning off a low power device such as MSP430 is not
an easy thing for who doesn't know much about hardware, and it seems
to be the case of this OP.
Any capacitor after the switch can hold the MSP running long enough
to allow the CPU to turn the switch ON again in case it goes to RESET
before the voltage is depleted enough. Of course it also depends on
the software, a failed SVS processing scheme, MSP430 model (without
SVS), consumption curve, etc.
The trick is to avoid any kind of extra reset after the software has
decided to go off.
One solution would be to switch off the power AND, at same time,
turn some output on to drain as many current as possible from
decoupling and bypass capacitors around MSP430.
MSP430 needs so low power to work that I would not be surprised if
one could make it run with energy harvested from a radio antenna or
even a finger touch...
-Augusto
On Qui 24/09/09 17:28 , OneStone o...@bigpond.net.au sent:
A simple method of doing this is to use a solid state switch with a=20
momentary push button to power on the circuit, that is activated
through=20
one diode of a BAV70, the other diode is controlled from the MSP.
When=20
the button is pushed the MSP establishes the hold in signal to
maintain=20
power to the circuit, when you want to turn everything off the micro
drops the signal. Depending on what else is around a weak pull down
may=20
also be necessary
Al
old_cow_yellow wrote:
> I think the OP did not want it to wake up at all.
>=20
> What is "power off completely"? Even LPM5 is not without power.
>=20
> --- In m...@yahoogroups.com, "Michael" wrote:
>> Chernwu,
>> What do you mean by 'external IEs'?
>>
>> LPM4 will probably consume far less than the battery
self-discharge, so LPM4 is probably a very good solution.
>>
>> If you want to completely shut off the MSP, you can use a voltage
regulator with an enable pin like the TPS77001 or use a series fet.
>>
>> Your solution will greatly depend on how you intend to wake up
the MSP after you 'turned it off'. In turn, this will depend on how
the battery will be handled after the discharge condition (replace,
in-circuit charging, DC input feeding the MSP while separately
charging the battery, upon many others).
>>
>> Regards,
>> Michael K.
>>
>> --- In m...@yahoogroups.com, =C3=A5=EF=BF=BD=C2=B4=C3=A6=EF=BF=BD=C2=
=A9=C3=A6=C2=B7=C2=B3 wrote:
>>> Hello all:
>>>
>>> I want to power off MSP430 completely when the battery is lower
than a given
>>> value, now I am using __low_power_mode_4() intrinsic command,
but some
>>> external IEs are active also. I know I can disable this IEs by
some extra
>>> code, but dose any one know some easy ways to power it of?
>>>
>>> --=20
>>> Best Regards.
>>> Chernwu
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
>=20
>=20
>=20
>=20
> ------------------------------------
>=20
>
>=20
>
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - OneStone - Sep 24 17:36:18 2009
Hi Augusto, I know it isn't straightforward, but it isn't exactly hard.
My first MSP430 design did just that, and that used the 149 with the
stuffed reset, so it isn't rocket science (which my mate larry, who
worked with a guy who designed Rockets claims doesn't exist anyway!).
Typical systems have other circuits running, like LEDs, or motors. Even
if it were a problem in a specific system it is easy to get around. A
time delay on POR solves it by requiring the ON button to be held, as
does monitoring the push button through a high impedance voltage divider.
here are a few fun things you can run an MSP430 from:-
a grape
a dripping tap
an array of old carbon resistors picking up noise from the air
blood
a sneeze, or blowing your nose (yes folks this computer is truly snot
powered and I'm not talking about the OS!!)
a few LEDs
a loudspeaker being used a a microphone.
Some are less reliable than others, and I have tried a few more weird ways.
Cheers
Al
Augusto Einsfeldt wrote:
>
> Al, as you know turning off a low power device such as MSP430 is not
> an easy thing for who doesn't know much about hardware, and it seems
> to be the case of this OP.
> Any capacitor after the switch can hold the MSP running long enough
> to allow the CPU to turn the switch ON again in case it goes to RESET
> before the voltage is depleted enough. Of course it also depends on
> the software, a failed SVS processing scheme, MSP430 model (without
> SVS), consumption curve, etc.
> The trick is to avoid any kind of extra reset after the software has
> decided to go off.
> One solution would be to switch off the power AND, at same time,
> turn some output on to drain as many current as possible from
> decoupling and bypass capacitors around MSP430.
> MSP430 needs so low power to work that I would not be surprised if
> one could make it run with energy harvested from a radio antenna or
> even a finger touch...
> -Augusto
> On Qui 24/09/09 17:28 , OneStone o...@bigpond.net.au sent:
> A simple method of doing this is to use a solid state switch with a
> momentary push button to power on the circuit, that is activated
> through
> one diode of a BAV70, the other diode is controlled from the MSP.
> When
> the button is pushed the MSP establishes the hold in signal to
> maintain
> power to the circuit, when you want to turn everything off the micro
>
> drops the signal. Depending on what else is around a weak pull down
> may
> also be necessary
> Al
> old_cow_yellow wrote:
> > I think the OP did not want it to wake up at all.
> >
> > What is "power off completely"? Even LPM5 is not without power.
> >
> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> Chernwu,
> >> What do you mean by 'external IEs'?
> >>
> >> LPM4 will probably consume far less than the battery
> self-discharge, so LPM4 is probably a very good solution.
> >>
> >> If you want to completely shut off the MSP, you can use a voltage
> regulator with an enable pin like the TPS77001 or use a series fet.
> >>
> >> Your solution will greatly depend on how you intend to wake up
> the MSP after you 'turned it off'. In turn, this will depend on how
> the battery will be handled after the discharge condition (replace,
> in-circuit charging, DC input feeding the MSP while separately
> charging the battery, upon many others).
> >>
> >> Regards,
> >> Michael K.
> >>
> >> --- In m...@yahoogroups.com, ��淳 wrote:
> >>> Hello all:
> >>>
> >>> I want to power off MSP430 completely when the battery is lower
> than a given
> >>> value, now I am using __low_power_mode_4() intrinsic command,
> but some
> >>> external IEs are active also. I know I can disable this IEs by
> some extra
> >>> code, but dose any one know some easy ways to power it of?
> >>>
> >>> --
> >>> Best Regards.
> >>> Chernwu
> >>>
> >>>
> >>> [Non-text portions of this message have been removed]
> >>>
> >
> >
> >
> >
> > ------------------------------------
> >
> >
> >
> >
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
My first MSP430 design did just that, and that used the 149 with the
stuffed reset, so it isn't rocket science (which my mate larry, who
worked with a guy who designed Rockets claims doesn't exist anyway!).
Typical systems have other circuits running, like LEDs, or motors. Even
if it were a problem in a specific system it is easy to get around. A
time delay on POR solves it by requiring the ON button to be held, as
does monitoring the push button through a high impedance voltage divider.
here are a few fun things you can run an MSP430 from:-
a grape
a dripping tap
an array of old carbon resistors picking up noise from the air
blood
a sneeze, or blowing your nose (yes folks this computer is truly snot
powered and I'm not talking about the OS!!)
a few LEDs
a loudspeaker being used a a microphone.
Some are less reliable than others, and I have tried a few more weird ways.
Cheers
Al
Augusto Einsfeldt wrote:
>
> Al, as you know turning off a low power device such as MSP430 is not
> an easy thing for who doesn't know much about hardware, and it seems
> to be the case of this OP.
> Any capacitor after the switch can hold the MSP running long enough
> to allow the CPU to turn the switch ON again in case it goes to RESET
> before the voltage is depleted enough. Of course it also depends on
> the software, a failed SVS processing scheme, MSP430 model (without
> SVS), consumption curve, etc.
> The trick is to avoid any kind of extra reset after the software has
> decided to go off.
> One solution would be to switch off the power AND, at same time,
> turn some output on to drain as many current as possible from
> decoupling and bypass capacitors around MSP430.
> MSP430 needs so low power to work that I would not be surprised if
> one could make it run with energy harvested from a radio antenna or
> even a finger touch...
> -Augusto
> On Qui 24/09/09 17:28 , OneStone o...@bigpond.net.au sent:
> A simple method of doing this is to use a solid state switch with a
> momentary push button to power on the circuit, that is activated
> through
> one diode of a BAV70, the other diode is controlled from the MSP.
> When
> the button is pushed the MSP establishes the hold in signal to
> maintain
> power to the circuit, when you want to turn everything off the micro
>
> drops the signal. Depending on what else is around a weak pull down
> may
> also be necessary
> Al
> old_cow_yellow wrote:
> > I think the OP did not want it to wake up at all.
> >
> > What is "power off completely"? Even LPM5 is not without power.
> >
> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> Chernwu,
> >> What do you mean by 'external IEs'?
> >>
> >> LPM4 will probably consume far less than the battery
> self-discharge, so LPM4 is probably a very good solution.
> >>
> >> If you want to completely shut off the MSP, you can use a voltage
> regulator with an enable pin like the TPS77001 or use a series fet.
> >>
> >> Your solution will greatly depend on how you intend to wake up
> the MSP after you 'turned it off'. In turn, this will depend on how
> the battery will be handled after the discharge condition (replace,
> in-circuit charging, DC input feeding the MSP while separately
> charging the battery, upon many others).
> >>
> >> Regards,
> >> Michael K.
> >>
> >> --- In m...@yahoogroups.com, ��淳 wrote:
> >>> Hello all:
> >>>
> >>> I want to power off MSP430 completely when the battery is lower
> than a given
> >>> value, now I am using __low_power_mode_4() intrinsic command,
> but some
> >>> external IEs are active also. I know I can disable this IEs by
> some extra
> >>> code, but dose any one know some easy ways to power it of?
> >>>
> >>> --
> >>> Best Regards.
> >>> Chernwu
> >>>
> >>>
> >>> [Non-text portions of this message have been removed]
> >>>
> >
> >
> >
> >
> > ------------------------------------
> >
> >
> >
> >
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Can MSP430 be power off completely? - Michael - Sep 24 18:03:15 2009
Augusto,
> > A simple method of doing this is to use a solid state switch with
> > a momentary push button to power on the circuit, that is activated
> > through one diode of a BAV70, the other diode is controlled from
> > the MSP.
> > When the button is pushed the MSP establishes the hold in signal
> > to maintain power to the circuit, when you want to turn
> > everything off the micro drops the signal. Depending on what else
> > is around a weak pull down may also be necessary
> > Al
> Al, as you know turning off a low power device such as MSP430 is not
> an easy thing for who doesn't know much about hardware, and it seems
> to be the case of this OP.
> Any capacitor after the switch can hold the MSP running long enough
> to allow the CPU to turn the switch ON again in case it goes to=20
> RESET before the voltage is depleted enough.
I don't understand how that could happen. The MSP is opening the relay, so =
voltage should only decrease to the point where #RESET will go active or Vc=
c will be too low. What would cause #RESET to go active and then inactive a=
gain while Vcc is decreasing but still over the minimum for operation?=20
Unless there is some high voltage circuit that will produce a high voltage =
discharge to Vcc while powering down, it doesn't make any sense to me. Or d=
id you mean PUC or POR instead of the RESET pin?
> One solution would be to switch off the power AND, at same time,
> turn some output on to drain as many current as possible from
> decoupling and bypass capacitors around MSP430.
That could easily be accomplished by using an SPDT relay:
NO : Vbat
COM: MSP Vcc
NC : GND (or discharge resistor to GND)
Of course, a mechanical monostable relay might consume too much during oper=
ation to make this a practical solution, unless you use a latching relay.
Regards,
Michael K.
--- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>
>=20=20
> Al, as you know turning off a low power device such as MSP430 is not
> an easy thing for who doesn't know much about hardware, and it seems
> to be the case of this OP.
> Any capacitor after the switch can hold the MSP running long enough
> to allow the CPU to turn the switch ON again in case it goes to RESET
> before the voltage is depleted enough. Of course it also depends on
> the software, a failed SVS processing scheme, MSP430 model (without
> SVS), consumption curve, etc.
> The trick is to avoid any kind of extra reset after the software has
> decided to go off.
> One solution would be to switch off the power AND, at same time,
> turn some output on to drain as many current as possible from
> decoupling and bypass capacitors around MSP430.
> MSP430 needs so low power to work that I would not be surprised if
> one could make it run with energy harvested from a radio antenna or
> even a finger touch...
> -Augusto
> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
> A simple method of doing this is to use a solid state switch with a=20
> momentary push button to power on the circuit, that is activated
> through=20
> one diode of a BAV70, the other diode is controlled from the MSP.
> When=20
> the button is pushed the MSP establishes the hold in signal to
> maintain=20
> power to the circuit, when you want to turn everything off the micro
>=20
> drops the signal. Depending on what else is around a weak pull down
> may=20
> also be necessary
> Al
> old_cow_yellow wrote:
> > I think the OP did not want it to wake up at all.
> >=20
> > What is "power off completely"? Even LPM5 is not without power.
> >=20
> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> Chernwu,
> >> What do you mean by 'external IEs'?
> >>
> >> LPM4 will probably consume far less than the battery
> self-discharge, so LPM4 is probably a very good solution.
> >>
> >> If you want to completely shut off the MSP, you can use a voltage
> regulator with an enable pin like the TPS77001 or use a series fet.
> >>
> >> Your solution will greatly depend on how you intend to wake up
> the MSP after you 'turned it off'. In turn, this will depend on how
> the battery will be handled after the discharge condition (replace,
> in-circuit charging, DC input feeding the MSP while separately
> charging the battery, upon many others).
> >>
> >> Regards,
> >> Michael K.
> >>
> >> --- In m...@yahoogroups.com, =C3=A5=EF=BF=BD=C2=B4=C3=A6=EF=BF=BD=
=C2=A9=C3=A6=C2=B7=C2=B3 wrote:
> >>> Hello all:
> >>>
> >>> I want to power off MSP430 completely when the battery is lower
> than a given
> >>> value, now I am using __low_power_mode_4() intrinsic command,
> but some
> >>> external IEs are active also. I know I can disable this IEs by
> some extra
> >>> code, but dose any one know some easy ways to power it of?
> >>>
> >>> --=20
> >>> Best Regards.
> >>> Chernwu
> >>>
> >>>
> >>> [Non-text portions of this message have been removed]
> >>>
> >=20
> >=20
> >=20
> >=20
> > ------------------------------------
> >=20
> >
> >=20
> >
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
> > A simple method of doing this is to use a solid state switch with
> > a momentary push button to power on the circuit, that is activated
> > through one diode of a BAV70, the other diode is controlled from
> > the MSP.
> > When the button is pushed the MSP establishes the hold in signal
> > to maintain power to the circuit, when you want to turn
> > everything off the micro drops the signal. Depending on what else
> > is around a weak pull down may also be necessary
> > Al
> Al, as you know turning off a low power device such as MSP430 is not
> an easy thing for who doesn't know much about hardware, and it seems
> to be the case of this OP.
> Any capacitor after the switch can hold the MSP running long enough
> to allow the CPU to turn the switch ON again in case it goes to=20
> RESET before the voltage is depleted enough.
I don't understand how that could happen. The MSP is opening the relay, so =
voltage should only decrease to the point where #RESET will go active or Vc=
c will be too low. What would cause #RESET to go active and then inactive a=
gain while Vcc is decreasing but still over the minimum for operation?=20
Unless there is some high voltage circuit that will produce a high voltage =
discharge to Vcc while powering down, it doesn't make any sense to me. Or d=
id you mean PUC or POR instead of the RESET pin?
> One solution would be to switch off the power AND, at same time,
> turn some output on to drain as many current as possible from
> decoupling and bypass capacitors around MSP430.
That could easily be accomplished by using an SPDT relay:
NO : Vbat
COM: MSP Vcc
NC : GND (or discharge resistor to GND)
Of course, a mechanical monostable relay might consume too much during oper=
ation to make this a practical solution, unless you use a latching relay.
Regards,
Michael K.
--- In m...@yahoogroups.com, Augusto Einsfeldt
>
>=20=20
> Al, as you know turning off a low power device such as MSP430 is not
> an easy thing for who doesn't know much about hardware, and it seems
> to be the case of this OP.
> Any capacitor after the switch can hold the MSP running long enough
> to allow the CPU to turn the switch ON again in case it goes to RESET
> before the voltage is depleted enough. Of course it also depends on
> the software, a failed SVS processing scheme, MSP430 model (without
> SVS), consumption curve, etc.
> The trick is to avoid any kind of extra reset after the software has
> decided to go off.
> One solution would be to switch off the power AND, at same time,
> turn some output on to drain as many current as possible from
> decoupling and bypass capacitors around MSP430.
> MSP430 needs so low power to work that I would not be surprised if
> one could make it run with energy harvested from a radio antenna or
> even a finger touch...
> -Augusto
> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
> A simple method of doing this is to use a solid state switch with a=20
> momentary push button to power on the circuit, that is activated
> through=20
> one diode of a BAV70, the other diode is controlled from the MSP.
> When=20
> the button is pushed the MSP establishes the hold in signal to
> maintain=20
> power to the circuit, when you want to turn everything off the micro
>=20
> drops the signal. Depending on what else is around a weak pull down
> may=20
> also be necessary
> Al
> old_cow_yellow wrote:
> > I think the OP did not want it to wake up at all.
> >=20
> > What is "power off completely"? Even LPM5 is not without power.
> >=20
> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> Chernwu,
> >> What do you mean by 'external IEs'?
> >>
> >> LPM4 will probably consume far less than the battery
> self-discharge, so LPM4 is probably a very good solution.
> >>
> >> If you want to completely shut off the MSP, you can use a voltage
> regulator with an enable pin like the TPS77001 or use a series fet.
> >>
> >> Your solution will greatly depend on how you intend to wake up
> the MSP after you 'turned it off'. In turn, this will depend on how
> the battery will be handled after the discharge condition (replace,
> in-circuit charging, DC input feeding the MSP while separately
> charging the battery, upon many others).
> >>
> >> Regards,
> >> Michael K.
> >>
> >> --- In m...@yahoogroups.com, =C3=A5=EF=BF=BD=C2=B4=C3=A6=EF=BF=BD=
=C2=A9=C3=A6=C2=B7=C2=B3 wrote:
> >>> Hello all:
> >>>
> >>> I want to power off MSP430 completely when the battery is lower
> than a given
> >>> value, now I am using __low_power_mode_4() intrinsic command,
> but some
> >>> external IEs are active also. I know I can disable this IEs by
> some extra
> >>> code, but dose any one know some easy ways to power it of?
> >>>
> >>> --=20
> >>> Best Regards.
> >>> Chernwu
> >>>
> >>>
> >>> [Non-text portions of this message have been removed]
> >>>
> >=20
> >=20
> >=20
> >=20
> > ------------------------------------
> >=20
> >
> >=20
> >
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - OneStone - Sep 24 18:10:37 2009
Michael the original 1121 and 149 parts were infamous for not fully
powering down, and not recovering either. Once turned off even a very
tiny amount of voltage in a cap would cause this, typically 0.4V was
enough, and once the micro switched off its clocks and all its
peripherals it draws next to nothing. The POR circuit of these parts
didn't actually force the reset condition from there, and this is what I
think Augusto was talking about. A lot of large caps (I have one design
with a couple of 1500uF caps in it) can store enough make the micro
think the button has been pressed again (potentially) but if you are
aware of this it is easily solved.
Al
Michael wrote:
> Augusto,
>>> A simple method of doing this is to use a solid state switch with
>>> a momentary push button to power on the circuit, that is activated
>>> through one diode of a BAV70, the other diode is controlled from
>>> the MSP.
>>> When the button is pushed the MSP establishes the hold in signal
>>> to maintain power to the circuit, when you want to turn
>>> everything off the micro drops the signal. Depending on what else
>>> is around a weak pull down may also be necessary
>>> Al
>
>> Al, as you know turning off a low power device such as MSP430 is not
>> an easy thing for who doesn't know much about hardware, and it seems
>> to be the case of this OP.
>> Any capacitor after the switch can hold the MSP running long enough
>> to allow the CPU to turn the switch ON again in case it goes to
>> RESET before the voltage is depleted enough.
>
> I don't understand how that could happen. The MSP is opening the relay, so voltage should only decrease to the point where #RESET will go active or Vcc will be too low. What would cause #RESET to go active and then inactive again while Vcc is decreasing but still over the minimum for operation?
> Unless there is some high voltage circuit that will produce a high voltage discharge to Vcc while powering down, it doesn't make any sense to me. Or did you mean PUC or POR instead of the RESET pin?
>
>> One solution would be to switch off the power AND, at same time,
>> turn some output on to drain as many current as possible from
>> decoupling and bypass capacitors around MSP430.
> That could easily be accomplished by using an SPDT relay:
> NO : Vbat
> COM: MSP Vcc
> NC : GND (or discharge resistor to GND)
> Of course, a mechanical monostable relay might consume too much during operation to make this a practical solution, unless you use a latching relay.
>
> Regards,
> Michael K.
>
> --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>>
>> Al, as you know turning off a low power device such as MSP430 is not
>> an easy thing for who doesn't know much about hardware, and it seems
>> to be the case of this OP.
>> Any capacitor after the switch can hold the MSP running long enough
>> to allow the CPU to turn the switch ON again in case it goes to RESET
>> before the voltage is depleted enough. Of course it also depends on
>> the software, a failed SVS processing scheme, MSP430 model (without
>> SVS), consumption curve, etc.
>> The trick is to avoid any kind of extra reset after the software has
>> decided to go off.
>> One solution would be to switch off the power AND, at same time,
>> turn some output on to drain as many current as possible from
>> decoupling and bypass capacitors around MSP430.
>> MSP430 needs so low power to work that I would not be surprised if
>> one could make it run with energy harvested from a radio antenna or
>> even a finger touch...
>> -Augusto
>> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
>> A simple method of doing this is to use a solid state switch with a
>> momentary push button to power on the circuit, that is activated
>> through
>> one diode of a BAV70, the other diode is controlled from the MSP.
>> When
>> the button is pushed the MSP establishes the hold in signal to
>> maintain
>> power to the circuit, when you want to turn everything off the micro
>>
>> drops the signal. Depending on what else is around a weak pull down
>> may
>> also be necessary
>> Al
>> old_cow_yellow wrote:
>> > I think the OP did not want it to wake up at all.
>> >
>> > What is "power off completely"? Even LPM5 is not without power.
>> >
>> > --- In m...@yahoogroups.com, "Michael" wrote:
>> >> Chernwu,
>> >> What do you mean by 'external IEs'?
>> >>
>> >> LPM4 will probably consume far less than the battery
>> self-discharge, so LPM4 is probably a very good solution.
>> >>
>> >> If you want to completely shut off the MSP, you can use a voltage
>> regulator with an enable pin like the TPS77001 or use a series fet.
>> >>
>> >> Your solution will greatly depend on how you intend to wake up
>> the MSP after you 'turned it off'. In turn, this will depend on how
>> the battery will be handled after the discharge condition (replace,
>> in-circuit charging, DC input feeding the MSP while separately
>> charging the battery, upon many others).
>> >>
>> >> Regards,
>> >> Michael K.
>> >>
>> >> --- In m...@yahoogroups.com, ��淳 wrote:
>> >>> Hello all:
>> >>>
>> >>> I want to power off MSP430 completely when the battery is lower
>> than a given
>> >>> value, now I am using __low_power_mode_4() intrinsic command,
>> but some
>> >>> external IEs are active also. I know I can disable this IEs by
>> some extra
>> >>> code, but dose any one know some easy ways to power it of?
>> >>>
>> >>> --
>> >>> Best Regards.
>> >>> Chernwu
>> >>>
>> >>>
>> >>> [Non-text portions of this message have been removed]
>> >>>
>> >
>> >
>> >
>> >
>> > ------------------------------------
>> >
>> >
>> >
>> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
powering down, and not recovering either. Once turned off even a very
tiny amount of voltage in a cap would cause this, typically 0.4V was
enough, and once the micro switched off its clocks and all its
peripherals it draws next to nothing. The POR circuit of these parts
didn't actually force the reset condition from there, and this is what I
think Augusto was talking about. A lot of large caps (I have one design
with a couple of 1500uF caps in it) can store enough make the micro
think the button has been pressed again (potentially) but if you are
aware of this it is easily solved.
Al
Michael wrote:
> Augusto,
>>> A simple method of doing this is to use a solid state switch with
>>> a momentary push button to power on the circuit, that is activated
>>> through one diode of a BAV70, the other diode is controlled from
>>> the MSP.
>>> When the button is pushed the MSP establishes the hold in signal
>>> to maintain power to the circuit, when you want to turn
>>> everything off the micro drops the signal. Depending on what else
>>> is around a weak pull down may also be necessary
>>> Al
>
>> Al, as you know turning off a low power device such as MSP430 is not
>> an easy thing for who doesn't know much about hardware, and it seems
>> to be the case of this OP.
>> Any capacitor after the switch can hold the MSP running long enough
>> to allow the CPU to turn the switch ON again in case it goes to
>> RESET before the voltage is depleted enough.
>
> I don't understand how that could happen. The MSP is opening the relay, so voltage should only decrease to the point where #RESET will go active or Vcc will be too low. What would cause #RESET to go active and then inactive again while Vcc is decreasing but still over the minimum for operation?
> Unless there is some high voltage circuit that will produce a high voltage discharge to Vcc while powering down, it doesn't make any sense to me. Or did you mean PUC or POR instead of the RESET pin?
>
>> One solution would be to switch off the power AND, at same time,
>> turn some output on to drain as many current as possible from
>> decoupling and bypass capacitors around MSP430.
> That could easily be accomplished by using an SPDT relay:
> NO : Vbat
> COM: MSP Vcc
> NC : GND (or discharge resistor to GND)
> Of course, a mechanical monostable relay might consume too much during operation to make this a practical solution, unless you use a latching relay.
>
> Regards,
> Michael K.
>
> --- In m...@yahoogroups.com, Augusto Einsfeldt
>>
>> Al, as you know turning off a low power device such as MSP430 is not
>> an easy thing for who doesn't know much about hardware, and it seems
>> to be the case of this OP.
>> Any capacitor after the switch can hold the MSP running long enough
>> to allow the CPU to turn the switch ON again in case it goes to RESET
>> before the voltage is depleted enough. Of course it also depends on
>> the software, a failed SVS processing scheme, MSP430 model (without
>> SVS), consumption curve, etc.
>> The trick is to avoid any kind of extra reset after the software has
>> decided to go off.
>> One solution would be to switch off the power AND, at same time,
>> turn some output on to drain as many current as possible from
>> decoupling and bypass capacitors around MSP430.
>> MSP430 needs so low power to work that I would not be surprised if
>> one could make it run with energy harvested from a radio antenna or
>> even a finger touch...
>> -Augusto
>> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
>> A simple method of doing this is to use a solid state switch with a
>> momentary push button to power on the circuit, that is activated
>> through
>> one diode of a BAV70, the other diode is controlled from the MSP.
>> When
>> the button is pushed the MSP establishes the hold in signal to
>> maintain
>> power to the circuit, when you want to turn everything off the micro
>>
>> drops the signal. Depending on what else is around a weak pull down
>> may
>> also be necessary
>> Al
>> old_cow_yellow wrote:
>> > I think the OP did not want it to wake up at all.
>> >
>> > What is "power off completely"? Even LPM5 is not without power.
>> >
>> > --- In m...@yahoogroups.com, "Michael" wrote:
>> >> Chernwu,
>> >> What do you mean by 'external IEs'?
>> >>
>> >> LPM4 will probably consume far less than the battery
>> self-discharge, so LPM4 is probably a very good solution.
>> >>
>> >> If you want to completely shut off the MSP, you can use a voltage
>> regulator with an enable pin like the TPS77001 or use a series fet.
>> >>
>> >> Your solution will greatly depend on how you intend to wake up
>> the MSP after you 'turned it off'. In turn, this will depend on how
>> the battery will be handled after the discharge condition (replace,
>> in-circuit charging, DC input feeding the MSP while separately
>> charging the battery, upon many others).
>> >>
>> >> Regards,
>> >> Michael K.
>> >>
>> >> --- In m...@yahoogroups.com, ��淳 wrote:
>> >>> Hello all:
>> >>>
>> >>> I want to power off MSP430 completely when the battery is lower
>> than a given
>> >>> value, now I am using __low_power_mode_4() intrinsic command,
>> but some
>> >>> external IEs are active also. I know I can disable this IEs by
>> some extra
>> >>> code, but dose any one know some easy ways to power it of?
>> >>>
>> >>> --
>> >>> Best Regards.
>> >>> Chernwu
>> >>>
>> >>>
>> >>> [Non-text portions of this message have been removed]
>> >>>
>> >
>> >
>> >
>> >
>> > ------------------------------------
>> >
>> >
>> >
>> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - Augusto Einsfeldt - Sep 24 19:16:24 2009
=20
It is exactly what I was talking about. Of course, as in any other
case it is all about design.
I also have seen MSP430 working from leakage current feed by
transistors that were connected to anopther power supply.
In low power mode the MSP430 could draw as little as10uA. A 10uF
capacitor would supply this for 200ms with a drop of only 0.2V.
Of course, if the CPU awake during this time the current drawn would
be more, say 2mA. Even with this amount of current the 10uF capacitor
will let the voltage drop 0.2V in 1ms. Again, since the MSP430=C2=B4s
wake-up is around 6us the software will have much more than 1,000
instructions to run (with 1MHz clock) before it notice the voltage is
below the minimum - and at 1MHz the CPU can run till the voltage drops
below 1.8V.
In that leakage current case the CPU detected the low voltage the
first time and entered in deep sleep. The leakage current went
charging the bypass and feed capacitors (0.1uF + 10uF) till the point
the MSP thought it was a power up. Then it drawn the current till the
voltage droped again and entered in deep sleep. The process behaved
like an oscilator.
Like Al has written, it is not rocket science but demands some
hardware - and software - knowledge to avoid pitfalls.
One good way to avoid processor doing opperations it could not do,
due the low voltage, would be to write in the FLASH a flag. It would
say: the battery has run out (of course, doing it before it is too
depleted to allow a reliable FLASH write). A checksum for this kind
of flag is a must!
Then after any RESET one thing to check is this flag - or the
availability of good power - before allowing the software to do any
serious job.
-Augusto
On Qui 24/09/09 19:10 , OneStone o...@bigpond.net.au sent:
Michael the original 1121 and 149 parts were infamous for not fully=20
powering down, and not recovering either. Once turned off even a
very=20
tiny amount of voltage in a cap would cause this, typically 0.4V was
enough, and once the micro switched off its clocks and all its=20
peripherals it draws next to nothing. The POR circuit of these parts
didn't actually force the reset condition from there, and this is
what I=20
think Augusto was talking about. A lot of large caps (I have one
design=20
with a couple of 1500uF caps in it) can store enough make the micro=20
think the button has been pressed again (potentially) but if you are
aware of this it is easily solved.
Al
Michael wrote:
> Augusto,
>>> A simple method of doing this is to use a solid state switch
with
>>> a momentary push button to power on the circuit, that is
activated
>>> through one diode of a BAV70, the other diode is controlled from
>>> the MSP.
>>> When the button is pushed the MSP establishes the hold in signal
>>> to maintain power to the circuit, when you want to turn
>>> everything off the micro drops the signal. Depending on what
else
>>> is around a weak pull down may also be necessary
>>> Al
>=20
>> Al, as you know turning off a low power device such as MSP430 is
not
>> an easy thing for who doesn't know much about hardware, and it
seems
>> to be the case of this OP.
>> Any capacitor after the switch can hold the MSP running long
enough
>> to allow the CPU to turn the switch ON again in case it goes to=20
>> RESET before the voltage is depleted enough.
>=20
> I don't understand how that could happen. The MSP is opening the
relay, so voltage should only decrease to the point where #RESET will
go active or Vcc will be too low. What would cause #RESET to go active
and then inactive again while Vcc is decreasing but still over the
minimum for operation?=20
> Unless there is some high voltage circuit that will produce a high
voltage discharge to Vcc while powering down, it doesn't make any
sense to me. Or did you mean PUC or POR instead of the RESET pin?
>=20
>> One solution would be to switch off the power AND, at same time,
>> turn some output on to drain as many current as possible from
>> decoupling and bypass capacitors around MSP430.
> That could easily be accomplished by using an SPDT relay:
> NO : Vbat
> COM: MSP Vcc
> NC : GND (or discharge resistor to GND)
> Of course, a mechanical monostable relay might consume too much
during operation to make this a practical solution, unless you use a
latching relay.
>=20
> Regards,
> Michael K.
>=20
> --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>>=20=20
>> Al, as you know turning off a low power device such as MSP430 is
not
>> an easy thing for who doesn't know much about hardware, and it
seems
>> to be the case of this OP.
>> Any capacitor after the switch can hold the MSP running long
enough
>> to allow the CPU to turn the switch ON again in case it goes to
RESET
>> before the voltage is depleted enough. Of course it also depends
on
>> the software, a failed SVS processing scheme, MSP430 model
(without
>> SVS), consumption curve, etc.
>> The trick is to avoid any kind of extra reset after the software
has
>> decided to go off.
>> One solution would be to switch off the power AND, at same time,
>> turn some output on to drain as many current as possible from
>> decoupling and bypass capacitors around MSP430.
>> MSP430 needs so low power to work that I would not be surprised
if
>> one could make it run with energy harvested from a radio antenna
or
>> even a finger touch...
>> -Augusto
>> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
>> A simple method of doing this is to use a solid state switch
with a=20
>> momentary push button to power on the circuit, that is activated
>> through=20
>> one diode of a BAV70, the other diode is controlled from the
MSP.
>> When=20
>> the button is pushed the MSP establishes the hold in signal to
>> maintain=20
>> power to the circuit, when you want to turn everything off the
micro
>>
>> drops the signal. Depending on what else is around a weak pull
down
>> may=20
>> also be necessary
>> Al
>> old_cow_yellow wrote:
>> > I think the OP did not want it to wake up at all.
>> >=20
>> > What is "power off completely"? Even LPM5 is not without
power.
>> >=20
>> > --- In m...@yahoogroups.com, "Michael" wrote:
>> >> Chernwu,
>> >> What do you mean by 'external IEs'?
>> >>
>> >> LPM4 will probably consume far less than the battery
>> self-discharge, so LPM4 is probably a very good solution.
>> >>
>> >> If you want to completely shut off the MSP, you can use a
voltage
>> regulator with an enable pin like the TPS77001 or use a series
fet.
>> >>
>> >> Your solution will greatly depend on how you intend to wake
up
>> the MSP after you 'turned it off'. In turn, this will depend on
how
>> the battery will be handled after the discharge condition
(replace,
>> in-circuit charging, DC input feeding the MSP while separately
>> charging the battery, upon many others).
>> >>
>> >> Regards,
>> >> Michael K.
>> >>
>> >> --- In m...@yahoogroups.com,
=C3=83=C2=A5=C3=AF=C2=BF=C2=BD=C3=82=C2=B4=C3=83=C2=A6=C3=AF=C2=BF=C2=BD=C3=
=82=C2=A9=C3=83=C2=A6=C3=82=C2=B7=C3=82=C2=B3 wrote:
>> >>> Hello all:
>> >>>
>> >>> I want to power off MSP430 completely when the battery is
lower
>> than a given
>> >>> value, now I am using __low_power_mode_4() intrinsic
command,
>> but some
>> >>> external IEs are active also. I know I can disable this IEs
by
>> some extra
>> >>> code, but dose any one know some easy ways to power it of?
>> >>>
>> >>> --=20
>> >>> Best Regards.
>> >>> Chernwu
>> >>>
>> >>>
>> >>> [Non-text portions of this message have been removed]
>> >>>
>> >=20
>> >=20
>> >=20
>> >=20
>> > ------------------------------------
>> >=20
>> >
>> >=20
>> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
It is exactly what I was talking about. Of course, as in any other
case it is all about design.
I also have seen MSP430 working from leakage current feed by
transistors that were connected to anopther power supply.
In low power mode the MSP430 could draw as little as10uA. A 10uF
capacitor would supply this for 200ms with a drop of only 0.2V.
Of course, if the CPU awake during this time the current drawn would
be more, say 2mA. Even with this amount of current the 10uF capacitor
will let the voltage drop 0.2V in 1ms. Again, since the MSP430=C2=B4s
wake-up is around 6us the software will have much more than 1,000
instructions to run (with 1MHz clock) before it notice the voltage is
below the minimum - and at 1MHz the CPU can run till the voltage drops
below 1.8V.
In that leakage current case the CPU detected the low voltage the
first time and entered in deep sleep. The leakage current went
charging the bypass and feed capacitors (0.1uF + 10uF) till the point
the MSP thought it was a power up. Then it drawn the current till the
voltage droped again and entered in deep sleep. The process behaved
like an oscilator.
Like Al has written, it is not rocket science but demands some
hardware - and software - knowledge to avoid pitfalls.
One good way to avoid processor doing opperations it could not do,
due the low voltage, would be to write in the FLASH a flag. It would
say: the battery has run out (of course, doing it before it is too
depleted to allow a reliable FLASH write). A checksum for this kind
of flag is a must!
Then after any RESET one thing to check is this flag - or the
availability of good power - before allowing the software to do any
serious job.
-Augusto
On Qui 24/09/09 19:10 , OneStone o...@bigpond.net.au sent:
Michael the original 1121 and 149 parts were infamous for not fully=20
powering down, and not recovering either. Once turned off even a
very=20
tiny amount of voltage in a cap would cause this, typically 0.4V was
enough, and once the micro switched off its clocks and all its=20
peripherals it draws next to nothing. The POR circuit of these parts
didn't actually force the reset condition from there, and this is
what I=20
think Augusto was talking about. A lot of large caps (I have one
design=20
with a couple of 1500uF caps in it) can store enough make the micro=20
think the button has been pressed again (potentially) but if you are
aware of this it is easily solved.
Al
Michael wrote:
> Augusto,
>>> A simple method of doing this is to use a solid state switch
with
>>> a momentary push button to power on the circuit, that is
activated
>>> through one diode of a BAV70, the other diode is controlled from
>>> the MSP.
>>> When the button is pushed the MSP establishes the hold in signal
>>> to maintain power to the circuit, when you want to turn
>>> everything off the micro drops the signal. Depending on what
else
>>> is around a weak pull down may also be necessary
>>> Al
>=20
>> Al, as you know turning off a low power device such as MSP430 is
not
>> an easy thing for who doesn't know much about hardware, and it
seems
>> to be the case of this OP.
>> Any capacitor after the switch can hold the MSP running long
enough
>> to allow the CPU to turn the switch ON again in case it goes to=20
>> RESET before the voltage is depleted enough.
>=20
> I don't understand how that could happen. The MSP is opening the
relay, so voltage should only decrease to the point where #RESET will
go active or Vcc will be too low. What would cause #RESET to go active
and then inactive again while Vcc is decreasing but still over the
minimum for operation?=20
> Unless there is some high voltage circuit that will produce a high
voltage discharge to Vcc while powering down, it doesn't make any
sense to me. Or did you mean PUC or POR instead of the RESET pin?
>=20
>> One solution would be to switch off the power AND, at same time,
>> turn some output on to drain as many current as possible from
>> decoupling and bypass capacitors around MSP430.
> That could easily be accomplished by using an SPDT relay:
> NO : Vbat
> COM: MSP Vcc
> NC : GND (or discharge resistor to GND)
> Of course, a mechanical monostable relay might consume too much
during operation to make this a practical solution, unless you use a
latching relay.
>=20
> Regards,
> Michael K.
>=20
> --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>>=20=20
>> Al, as you know turning off a low power device such as MSP430 is
not
>> an easy thing for who doesn't know much about hardware, and it
seems
>> to be the case of this OP.
>> Any capacitor after the switch can hold the MSP running long
enough
>> to allow the CPU to turn the switch ON again in case it goes to
RESET
>> before the voltage is depleted enough. Of course it also depends
on
>> the software, a failed SVS processing scheme, MSP430 model
(without
>> SVS), consumption curve, etc.
>> The trick is to avoid any kind of extra reset after the software
has
>> decided to go off.
>> One solution would be to switch off the power AND, at same time,
>> turn some output on to drain as many current as possible from
>> decoupling and bypass capacitors around MSP430.
>> MSP430 needs so low power to work that I would not be surprised
if
>> one could make it run with energy harvested from a radio antenna
or
>> even a finger touch...
>> -Augusto
>> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
>> A simple method of doing this is to use a solid state switch
with a=20
>> momentary push button to power on the circuit, that is activated
>> through=20
>> one diode of a BAV70, the other diode is controlled from the
MSP.
>> When=20
>> the button is pushed the MSP establishes the hold in signal to
>> maintain=20
>> power to the circuit, when you want to turn everything off the
micro
>>
>> drops the signal. Depending on what else is around a weak pull
down
>> may=20
>> also be necessary
>> Al
>> old_cow_yellow wrote:
>> > I think the OP did not want it to wake up at all.
>> >=20
>> > What is "power off completely"? Even LPM5 is not without
power.
>> >=20
>> > --- In m...@yahoogroups.com, "Michael" wrote:
>> >> Chernwu,
>> >> What do you mean by 'external IEs'?
>> >>
>> >> LPM4 will probably consume far less than the battery
>> self-discharge, so LPM4 is probably a very good solution.
>> >>
>> >> If you want to completely shut off the MSP, you can use a
voltage
>> regulator with an enable pin like the TPS77001 or use a series
fet.
>> >>
>> >> Your solution will greatly depend on how you intend to wake
up
>> the MSP after you 'turned it off'. In turn, this will depend on
how
>> the battery will be handled after the discharge condition
(replace,
>> in-circuit charging, DC input feeding the MSP while separately
>> charging the battery, upon many others).
>> >>
>> >> Regards,
>> >> Michael K.
>> >>
>> >> --- In m...@yahoogroups.com,
=C3=83=C2=A5=C3=AF=C2=BF=C2=BD=C3=82=C2=B4=C3=83=C2=A6=C3=AF=C2=BF=C2=BD=C3=
=82=C2=A9=C3=83=C2=A6=C3=82=C2=B7=C3=82=C2=B3 wrote:
>> >>> Hello all:
>> >>>
>> >>> I want to power off MSP430 completely when the battery is
lower
>> than a given
>> >>> value, now I am using __low_power_mode_4() intrinsic
command,
>> but some
>> >>> external IEs are active also. I know I can disable this IEs
by
>> some extra
>> >>> code, but dose any one know some easy ways to power it of?
>> >>>
>> >>> --=20
>> >>> Best Regards.
>> >>> Chernwu
>> >>>
>> >>>
>> >>> [Non-text portions of this message have been removed]
>> >>>
>> >=20
>> >=20
>> >=20
>> >=20
>> > ------------------------------------
>> >=20
>> >
>> >=20
>> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - OneStone - Sep 24 19:44:49 2009
10uA! Shock horror. The mean power budget for my data loggers is under
2uA. Seriously though, in practice the MSP430 wakes from sleep in well
under 1uS.
Al
Augusto Einsfeldt wrote:
>
> It is exactly what I was talking about. Of course, as in any other
> case it is all about design.
> I also have seen MSP430 working from leakage current feed by
> transistors that were connected to anopther power supply.
> In low power mode the MSP430 could draw as little as10uA. A 10uF
> capacitor would supply this for 200ms with a drop of only 0.2V.
> Of course, if the CPU awake during this time the current drawn would
> be more, say 2mA. Even with this amount of current the 10uF capacitor
> will let the voltage drop 0.2V in 1ms. Again, since the MSP430´s
> wake-up is around 6us the software will have much more than 1,000
> instructions to run (with 1MHz clock) before it notice the voltage is
> below the minimum - and at 1MHz the CPU can run till the voltage drops
> below 1.8V.
> In that leakage current case the CPU detected the low voltage the
> first time and entered in deep sleep. The leakage current went
> charging the bypass and feed capacitors (0.1uF + 10uF) till the point
> the MSP thought it was a power up. Then it drawn the current till the
> voltage droped again and entered in deep sleep. The process behaved
> like an oscilator.
> Like Al has written, it is not rocket science but demands some
> hardware - and software - knowledge to avoid pitfalls.
> One good way to avoid processor doing opperations it could not do,
> due the low voltage, would be to write in the FLASH a flag. It would
> say: the battery has run out (of course, doing it before it is too
> depleted to allow a reliable FLASH write). A checksum for this kind
> of flag is a must!
> Then after any RESET one thing to check is this flag - or the
> availability of good power - before allowing the software to do any
> serious job.
> -Augusto
> On Qui 24/09/09 19:10 , OneStone o...@bigpond.net.au sent:
> Michael the original 1121 and 149 parts were infamous for not fully
> powering down, and not recovering either. Once turned off even a
> very
> tiny amount of voltage in a cap would cause this, typically 0.4V was
>
> enough, and once the micro switched off its clocks and all its
> peripherals it draws next to nothing. The POR circuit of these parts
>
> didn't actually force the reset condition from there, and this is
> what I
> think Augusto was talking about. A lot of large caps (I have one
> design
> with a couple of 1500uF caps in it) can store enough make the micro
> think the button has been pressed again (potentially) but if you are
>
> aware of this it is easily solved.
> Al
> Michael wrote:
> > Augusto,
> >>> A simple method of doing this is to use a solid state switch
> with
> >>> a momentary push button to power on the circuit, that is
> activated
> >>> through one diode of a BAV70, the other diode is controlled from
> >>> the MSP.
> >>> When the button is pushed the MSP establishes the hold in signal
> >>> to maintain power to the circuit, when you want to turn
> >>> everything off the micro drops the signal. Depending on what
> else
> >>> is around a weak pull down may also be necessary
> >>> Al
> >
> >> Al, as you know turning off a low power device such as MSP430 is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes to
> >> RESET before the voltage is depleted enough.
> >
> > I don't understand how that could happen. The MSP is opening the
> relay, so voltage should only decrease to the point where #RESET will
> go active or Vcc will be too low. What would cause #RESET to go active
> and then inactive again while Vcc is decreasing but still over the
> minimum for operation?
> > Unless there is some high voltage circuit that will produce a high
> voltage discharge to Vcc while powering down, it doesn't make any
> sense to me. Or did you mean PUC or POR instead of the RESET pin?
> >
> >> One solution would be to switch off the power AND, at same time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> > That could easily be accomplished by using an SPDT relay:
> > NO : Vbat
> > COM: MSP Vcc
> > NC : GND (or discharge resistor to GND)
> > Of course, a mechanical monostable relay might consume too much
> during operation to make this a practical solution, unless you use a
> latching relay.
> >
> > Regards,
> > Michael K.
> >
> > --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
> >>
> >> Al, as you know turning off a low power device such as MSP430 is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes to
> RESET
> >> before the voltage is depleted enough. Of course it also depends
> on
> >> the software, a failed SVS processing scheme, MSP430 model
> (without
> >> SVS), consumption curve, etc.
> >> The trick is to avoid any kind of extra reset after the software
> has
> >> decided to go off.
> >> One solution would be to switch off the power AND, at same time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> >> MSP430 needs so low power to work that I would not be surprised
> if
> >> one could make it run with energy harvested from a radio antenna
> or
> >> even a finger touch...
> >> -Augusto
> >> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
> >> A simple method of doing this is to use a solid state switch
> with a
> >> momentary push button to power on the circuit, that is activated
> >> through
> >> one diode of a BAV70, the other diode is controlled from the
> MSP.
> >> When
> >> the button is pushed the MSP establishes the hold in signal to
> >> maintain
> >> power to the circuit, when you want to turn everything off the
> micro
> >>
> >> drops the signal. Depending on what else is around a weak pull
> down
> >> may
> >> also be necessary
> >> Al
> >> old_cow_yellow wrote:
> >> > I think the OP did not want it to wake up at all.
> >> >
> >> > What is "power off completely"? Even LPM5 is not without
> power.
> >> >
> >> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> >> Chernwu,
> >> >> What do you mean by 'external IEs'?
> >> >>
> >> >> LPM4 will probably consume far less than the battery
> >> self-discharge, so LPM4 is probably a very good solution.
> >> >>
> >> >> If you want to completely shut off the MSP, you can use a
> voltage
> >> regulator with an enable pin like the TPS77001 or use a series
> fet.
> >> >>
> >> >> Your solution will greatly depend on how you intend to wake
> up
> >> the MSP after you 'turned it off'. In turn, this will depend on
> how
> >> the battery will be handled after the discharge condition
> (replace,
> >> in-circuit charging, DC input feeding the MSP while separately
> >> charging the battery, upon many others).
> >> >>
> >> >> Regards,
> >> >> Michael K.
> >> >>
> >> >> --- In m...@yahoogroups.com,
> ��淳 wrote:
> >> >>> Hello all:
> >> >>>
> >> >>> I want to power off MSP430 completely when the battery is
> lower
> >> than a given
> >> >>> value, now I am using __low_power_mode_4() intrinsic
> command,
> >> but some
> >> >>> external IEs are active also. I know I can disable this IEs
> by
> >> some extra
> >> >>> code, but dose any one know some easy ways to power it of?
> >> >>>
> >> >>> --
> >> >>> Best Regards.
> >> >>> Chernwu
> >> >>>
> >> >>>
> >> >>> [Non-text portions of this message have been removed]
> >> >>>
> >> >
> >> >
> >> >
> >> >
> >> > ------------------------------------
> >> >
> >> >
> >> >
> >> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
2uA. Seriously though, in practice the MSP430 wakes from sleep in well
under 1uS.
Al
Augusto Einsfeldt wrote:
>
> It is exactly what I was talking about. Of course, as in any other
> case it is all about design.
> I also have seen MSP430 working from leakage current feed by
> transistors that were connected to anopther power supply.
> In low power mode the MSP430 could draw as little as10uA. A 10uF
> capacitor would supply this for 200ms with a drop of only 0.2V.
> Of course, if the CPU awake during this time the current drawn would
> be more, say 2mA. Even with this amount of current the 10uF capacitor
> will let the voltage drop 0.2V in 1ms. Again, since the MSP430´s
> wake-up is around 6us the software will have much more than 1,000
> instructions to run (with 1MHz clock) before it notice the voltage is
> below the minimum - and at 1MHz the CPU can run till the voltage drops
> below 1.8V.
> In that leakage current case the CPU detected the low voltage the
> first time and entered in deep sleep. The leakage current went
> charging the bypass and feed capacitors (0.1uF + 10uF) till the point
> the MSP thought it was a power up. Then it drawn the current till the
> voltage droped again and entered in deep sleep. The process behaved
> like an oscilator.
> Like Al has written, it is not rocket science but demands some
> hardware - and software - knowledge to avoid pitfalls.
> One good way to avoid processor doing opperations it could not do,
> due the low voltage, would be to write in the FLASH a flag. It would
> say: the battery has run out (of course, doing it before it is too
> depleted to allow a reliable FLASH write). A checksum for this kind
> of flag is a must!
> Then after any RESET one thing to check is this flag - or the
> availability of good power - before allowing the software to do any
> serious job.
> -Augusto
> On Qui 24/09/09 19:10 , OneStone o...@bigpond.net.au sent:
> Michael the original 1121 and 149 parts were infamous for not fully
> powering down, and not recovering either. Once turned off even a
> very
> tiny amount of voltage in a cap would cause this, typically 0.4V was
>
> enough, and once the micro switched off its clocks and all its
> peripherals it draws next to nothing. The POR circuit of these parts
>
> didn't actually force the reset condition from there, and this is
> what I
> think Augusto was talking about. A lot of large caps (I have one
> design
> with a couple of 1500uF caps in it) can store enough make the micro
> think the button has been pressed again (potentially) but if you are
>
> aware of this it is easily solved.
> Al
> Michael wrote:
> > Augusto,
> >>> A simple method of doing this is to use a solid state switch
> with
> >>> a momentary push button to power on the circuit, that is
> activated
> >>> through one diode of a BAV70, the other diode is controlled from
> >>> the MSP.
> >>> When the button is pushed the MSP establishes the hold in signal
> >>> to maintain power to the circuit, when you want to turn
> >>> everything off the micro drops the signal. Depending on what
> else
> >>> is around a weak pull down may also be necessary
> >>> Al
> >
> >> Al, as you know turning off a low power device such as MSP430 is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes to
> >> RESET before the voltage is depleted enough.
> >
> > I don't understand how that could happen. The MSP is opening the
> relay, so voltage should only decrease to the point where #RESET will
> go active or Vcc will be too low. What would cause #RESET to go active
> and then inactive again while Vcc is decreasing but still over the
> minimum for operation?
> > Unless there is some high voltage circuit that will produce a high
> voltage discharge to Vcc while powering down, it doesn't make any
> sense to me. Or did you mean PUC or POR instead of the RESET pin?
> >
> >> One solution would be to switch off the power AND, at same time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> > That could easily be accomplished by using an SPDT relay:
> > NO : Vbat
> > COM: MSP Vcc
> > NC : GND (or discharge resistor to GND)
> > Of course, a mechanical monostable relay might consume too much
> during operation to make this a practical solution, unless you use a
> latching relay.
> >
> > Regards,
> > Michael K.
> >
> > --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
> >>
> >> Al, as you know turning off a low power device such as MSP430 is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes to
> RESET
> >> before the voltage is depleted enough. Of course it also depends
> on
> >> the software, a failed SVS processing scheme, MSP430 model
> (without
> >> SVS), consumption curve, etc.
> >> The trick is to avoid any kind of extra reset after the software
> has
> >> decided to go off.
> >> One solution would be to switch off the power AND, at same time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> >> MSP430 needs so low power to work that I would not be surprised
> if
> >> one could make it run with energy harvested from a radio antenna
> or
> >> even a finger touch...
> >> -Augusto
> >> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
> >> A simple method of doing this is to use a solid state switch
> with a
> >> momentary push button to power on the circuit, that is activated
> >> through
> >> one diode of a BAV70, the other diode is controlled from the
> MSP.
> >> When
> >> the button is pushed the MSP establishes the hold in signal to
> >> maintain
> >> power to the circuit, when you want to turn everything off the
> micro
> >>
> >> drops the signal. Depending on what else is around a weak pull
> down
> >> may
> >> also be necessary
> >> Al
> >> old_cow_yellow wrote:
> >> > I think the OP did not want it to wake up at all.
> >> >
> >> > What is "power off completely"? Even LPM5 is not without
> power.
> >> >
> >> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> >> Chernwu,
> >> >> What do you mean by 'external IEs'?
> >> >>
> >> >> LPM4 will probably consume far less than the battery
> >> self-discharge, so LPM4 is probably a very good solution.
> >> >>
> >> >> If you want to completely shut off the MSP, you can use a
> voltage
> >> regulator with an enable pin like the TPS77001 or use a series
> fet.
> >> >>
> >> >> Your solution will greatly depend on how you intend to wake
> up
> >> the MSP after you 'turned it off'. In turn, this will depend on
> how
> >> the battery will be handled after the discharge condition
> (replace,
> >> in-circuit charging, DC input feeding the MSP while separately
> >> charging the battery, upon many others).
> >> >>
> >> >> Regards,
> >> >> Michael K.
> >> >>
> >> >> --- In m...@yahoogroups.com,
> ��淳 wrote:
> >> >>> Hello all:
> >> >>>
> >> >>> I want to power off MSP430 completely when the battery is
> lower
> >> than a given
> >> >>> value, now I am using __low_power_mode_4() intrinsic
> command,
> >> but some
> >> >>> external IEs are active also. I know I can disable this IEs
> by
> >> some extra
> >> >>> code, but dose any one know some easy ways to power it of?
> >> >>>
> >> >>> --
> >> >>> Best Regards.
> >> >>> Chernwu
> >> >>>
> >> >>>
> >> >>> [Non-text portions of this message have been removed]
> >> >>>
> >> >
> >> >
> >> >
> >> >
> >> > ------------------------------------
> >> >
> >> >
> >> >
> >> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - Augusto Einsfeldt - Sep 24 20:20:58 2009
Yes, of course. I did not check any data sheet before write, just
gave some budget to use as example.
On Qui 24/09/09 20:44 , OneStone o...@bigpond.net.au sent:
10uA! Shock horror. The mean power budget for my data loggers is
under=20
2uA. Seriously though, in practice the MSP430 wakes from sleep in
well=20
under 1uS.
Al
Augusto Einsfeldt wrote:
>=20=20
> It is exactly what I was talking about. Of course, as in any
other
> case it is all about design.
> I also have seen MSP430 working from leakage current feed by
> transistors that were connected to anopther power supply.
> In low power mode the MSP430 could draw as little as10uA. A 10uF
> capacitor would supply this for 200ms with a drop of only 0.2V.
> Of course, if the CPU awake during this time the current drawn
would
> be more, say 2mA. Even with this amount of current the 10uF
capacitor
> will let the voltage drop 0.2V in 1ms. Again, since the MSP430=C2=B4s
> wake-up is around 6us the software will have much more than 1,000
> instructions to run (with 1MHz clock) before it notice the voltage
is
> below the minimum - and at 1MHz the CPU can run till the voltage
drops
> below 1.8V.
> In that leakage current case the CPU detected the low voltage the
> first time and entered in deep sleep. The leakage current went
> charging the bypass and feed capacitors (0.1uF + 10uF) till the
point
> the MSP thought it was a power up. Then it drawn the current till
the
> voltage droped again and entered in deep sleep. The process
behaved
> like an oscilator.
> Like Al has written, it is not rocket science but demands some
> hardware - and software - knowledge to avoid pitfalls.
> One good way to avoid processor doing opperations it could not
do,
> due the low voltage, would be to write in the FLASH a flag. It
would
> say: the battery has run out (of course, doing it before it is too
> depleted to allow a reliable FLASH write). A checksum for this
kind
> of flag is a must!
> Then after any RESET one thing to check is this flag - or the
> availability of good power - before allowing the software to do
any
> serious job.
> -Augusto
> On Qui 24/09/09 19:10 , OneStone o...@bigpond.net.au sent:
> Michael the original 1121 and 149 parts were infamous for not
fully=20
> powering down, and not recovering either. Once turned off even a
> very=20
> tiny amount of voltage in a cap would cause this, typically 0.4V
was
>=20
> enough, and once the micro switched off its clocks and all its=20
> peripherals it draws next to nothing. The POR circuit of these
parts
>=20
> didn't actually force the reset condition from there, and this is
> what I=20
> think Augusto was talking about. A lot of large caps (I have one
> design=20
> with a couple of 1500uF caps in it) can store enough make the
micro=20
> think the button has been pressed again (potentially) but if you
are
>=20
> aware of this it is easily solved.
> Al
> Michael wrote:
> > Augusto,
> >>> A simple method of doing this is to use a solid state switch
> with
> >>> a momentary push button to power on the circuit, that is
> activated
> >>> through one diode of a BAV70, the other diode is controlled
from
> >>> the MSP.
> >>> When the button is pushed the MSP establishes the hold in
signal
> >>> to maintain power to the circuit, when you want to turn
> >>> everything off the micro drops the signal. Depending on what
> else
> >>> is around a weak pull down may also be necessary
> >>> Al
> >=20
> >> Al, as you know turning off a low power device such as MSP430
is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes
to=20
> >> RESET before the voltage is depleted enough.
> >=20
> > I don't understand how that could happen. The MSP is opening
the
> relay, so voltage should only decrease to the point where #RESET
will
> go active or Vcc will be too low. What would cause #RESET to go
active
> and then inactive again while Vcc is decreasing but still over the
> minimum for operation?=20
> > Unless there is some high voltage circuit that will produce a
high
> voltage discharge to Vcc while powering down, it doesn't make any
> sense to me. Or did you mean PUC or POR instead of the RESET pin?
> >=20
> >> One solution would be to switch off the power AND, at same
time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> > That could easily be accomplished by using an SPDT relay:
> > NO : Vbat
> > COM: MSP Vcc
> > NC : GND (or discharge resistor to GND)
> > Of course, a mechanical monostable relay might consume too much
> during operation to make this a practical solution, unless you use
a
> latching relay.
> >=20
> > Regards,
> > Michael K.
> >=20
> > --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
> >>=20=20
> >> Al, as you know turning off a low power device such as MSP430
is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes
to
> RESET
> >> before the voltage is depleted enough. Of course it also
depends
> on
> >> the software, a failed SVS processing scheme, MSP430 model
> (without
> >> SVS), consumption curve, etc.
> >> The trick is to avoid any kind of extra reset after the
software
> has
> >> decided to go off.
> >> One solution would be to switch off the power AND, at same
time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> >> MSP430 needs so low power to work that I would not be
surprised
> if
> >> one could make it run with energy harvested from a radio
antenna
> or
> >> even a finger touch...
> >> -Augusto
> >> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
> >> A simple method of doing this is to use a solid state switch
> with a=20
> >> momentary push button to power on the circuit, that is
activated
> >> through=20
> >> one diode of a BAV70, the other diode is controlled from the
> MSP.
> >> When=20
> >> the button is pushed the MSP establishes the hold in signal
to
> >> maintain=20
> >> power to the circuit, when you want to turn everything off
the
> micro
> >>
> >> drops the signal. Depending on what else is around a weak
pull
> down
> >> may=20
> >> also be necessary
> >> Al
> >> old_cow_yellow wrote:
> >> > I think the OP did not want it to wake up at all.
> >> >=20
> >> > What is "power off completely"? Even LPM5 is not without
> power.
> >> >=20
> >> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> >> Chernwu,
> >> >> What do you mean by 'external IEs'?
> >> >>
> >> >> LPM4 will probably consume far less than the battery
> >> self-discharge, so LPM4 is probably a very good solution.
> >> >>
> >> >> If you want to completely shut off the MSP, you can use a
> voltage
> >> regulator with an enable pin like the TPS77001 or use a series
> fet.
> >> >>
> >> >> Your solution will greatly depend on how you intend to
wake
> up
> >> the MSP after you 'turned it off'. In turn, this will depend
on
> how
> >> the battery will be handled after the discharge condition
> (replace,
> >> in-circuit charging, DC input feeding the MSP while separately
> >> charging the battery, upon many others).
> >> >>
> >> >> Regards,
> >> >> Michael K.
> >> >>
> >> >> --- In m...@yahoogroups.com,
> =C3=83=C2=A5=C3=AF=C2=BF=C2=BD=C3=82=C2=B4=C3=83=C2=A6=C3=AF=C2=BF=C2=BD=
=C3=82=C2=A9=C3=83=C2=A6=C3=82=C2=B7=C3=82=C2=B3 wrote:
> >> >>> Hello all:
> >> >>>
> >> >>> I want to power off MSP430 completely when the battery is
> lower
> >> than a given
> >> >>> value, now I am using __low_power_mode_4() intrinsic
> command,
> >> but some
> >> >>> external IEs are active also. I know I can disable this
IEs
> by
> >> some extra
> >> >>> code, but dose any one know some easy ways to power it
of?
> >> >>>
> >> >>> --=20
> >> >>> Best Regards.
> >> >>> Chernwu
> >> >>>
> >> >>>
> >> >>> [Non-text portions of this message have been removed]
> >> >>>
> >> >=20
> >> >=20
> >> >=20
> >> >=20
> >> > ------------------------------------
> >> >=20
> >> >
> >> >=20
> >> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
gave some budget to use as example.
On Qui 24/09/09 20:44 , OneStone o...@bigpond.net.au sent:
10uA! Shock horror. The mean power budget for my data loggers is
under=20
2uA. Seriously though, in practice the MSP430 wakes from sleep in
well=20
under 1uS.
Al
Augusto Einsfeldt wrote:
>=20=20
> It is exactly what I was talking about. Of course, as in any
other
> case it is all about design.
> I also have seen MSP430 working from leakage current feed by
> transistors that were connected to anopther power supply.
> In low power mode the MSP430 could draw as little as10uA. A 10uF
> capacitor would supply this for 200ms with a drop of only 0.2V.
> Of course, if the CPU awake during this time the current drawn
would
> be more, say 2mA. Even with this amount of current the 10uF
capacitor
> will let the voltage drop 0.2V in 1ms. Again, since the MSP430=C2=B4s
> wake-up is around 6us the software will have much more than 1,000
> instructions to run (with 1MHz clock) before it notice the voltage
is
> below the minimum - and at 1MHz the CPU can run till the voltage
drops
> below 1.8V.
> In that leakage current case the CPU detected the low voltage the
> first time and entered in deep sleep. The leakage current went
> charging the bypass and feed capacitors (0.1uF + 10uF) till the
point
> the MSP thought it was a power up. Then it drawn the current till
the
> voltage droped again and entered in deep sleep. The process
behaved
> like an oscilator.
> Like Al has written, it is not rocket science but demands some
> hardware - and software - knowledge to avoid pitfalls.
> One good way to avoid processor doing opperations it could not
do,
> due the low voltage, would be to write in the FLASH a flag. It
would
> say: the battery has run out (of course, doing it before it is too
> depleted to allow a reliable FLASH write). A checksum for this
kind
> of flag is a must!
> Then after any RESET one thing to check is this flag - or the
> availability of good power - before allowing the software to do
any
> serious job.
> -Augusto
> On Qui 24/09/09 19:10 , OneStone o...@bigpond.net.au sent:
> Michael the original 1121 and 149 parts were infamous for not
fully=20
> powering down, and not recovering either. Once turned off even a
> very=20
> tiny amount of voltage in a cap would cause this, typically 0.4V
was
>=20
> enough, and once the micro switched off its clocks and all its=20
> peripherals it draws next to nothing. The POR circuit of these
parts
>=20
> didn't actually force the reset condition from there, and this is
> what I=20
> think Augusto was talking about. A lot of large caps (I have one
> design=20
> with a couple of 1500uF caps in it) can store enough make the
micro=20
> think the button has been pressed again (potentially) but if you
are
>=20
> aware of this it is easily solved.
> Al
> Michael wrote:
> > Augusto,
> >>> A simple method of doing this is to use a solid state switch
> with
> >>> a momentary push button to power on the circuit, that is
> activated
> >>> through one diode of a BAV70, the other diode is controlled
from
> >>> the MSP.
> >>> When the button is pushed the MSP establishes the hold in
signal
> >>> to maintain power to the circuit, when you want to turn
> >>> everything off the micro drops the signal. Depending on what
> else
> >>> is around a weak pull down may also be necessary
> >>> Al
> >=20
> >> Al, as you know turning off a low power device such as MSP430
is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes
to=20
> >> RESET before the voltage is depleted enough.
> >=20
> > I don't understand how that could happen. The MSP is opening
the
> relay, so voltage should only decrease to the point where #RESET
will
> go active or Vcc will be too low. What would cause #RESET to go
active
> and then inactive again while Vcc is decreasing but still over the
> minimum for operation?=20
> > Unless there is some high voltage circuit that will produce a
high
> voltage discharge to Vcc while powering down, it doesn't make any
> sense to me. Or did you mean PUC or POR instead of the RESET pin?
> >=20
> >> One solution would be to switch off the power AND, at same
time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> > That could easily be accomplished by using an SPDT relay:
> > NO : Vbat
> > COM: MSP Vcc
> > NC : GND (or discharge resistor to GND)
> > Of course, a mechanical monostable relay might consume too much
> during operation to make this a practical solution, unless you use
a
> latching relay.
> >=20
> > Regards,
> > Michael K.
> >=20
> > --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
> >>=20=20
> >> Al, as you know turning off a low power device such as MSP430
is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes
to
> RESET
> >> before the voltage is depleted enough. Of course it also
depends
> on
> >> the software, a failed SVS processing scheme, MSP430 model
> (without
> >> SVS), consumption curve, etc.
> >> The trick is to avoid any kind of extra reset after the
software
> has
> >> decided to go off.
> >> One solution would be to switch off the power AND, at same
time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> >> MSP430 needs so low power to work that I would not be
surprised
> if
> >> one could make it run with energy harvested from a radio
antenna
> or
> >> even a finger touch...
> >> -Augusto
> >> On Qui 24/09/09 17:28 , OneStone onestone@... sent:
> >> A simple method of doing this is to use a solid state switch
> with a=20
> >> momentary push button to power on the circuit, that is
activated
> >> through=20
> >> one diode of a BAV70, the other diode is controlled from the
> MSP.
> >> When=20
> >> the button is pushed the MSP establishes the hold in signal
to
> >> maintain=20
> >> power to the circuit, when you want to turn everything off
the
> micro
> >>
> >> drops the signal. Depending on what else is around a weak
pull
> down
> >> may=20
> >> also be necessary
> >> Al
> >> old_cow_yellow wrote:
> >> > I think the OP did not want it to wake up at all.
> >> >=20
> >> > What is "power off completely"? Even LPM5 is not without
> power.
> >> >=20
> >> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> >> Chernwu,
> >> >> What do you mean by 'external IEs'?
> >> >>
> >> >> LPM4 will probably consume far less than the battery
> >> self-discharge, so LPM4 is probably a very good solution.
> >> >>
> >> >> If you want to completely shut off the MSP, you can use a
> voltage
> >> regulator with an enable pin like the TPS77001 or use a series
> fet.
> >> >>
> >> >> Your solution will greatly depend on how you intend to
wake
> up
> >> the MSP after you 'turned it off'. In turn, this will depend
on
> how
> >> the battery will be handled after the discharge condition
> (replace,
> >> in-circuit charging, DC input feeding the MSP while separately
> >> charging the battery, upon many others).
> >> >>
> >> >> Regards,
> >> >> Michael K.
> >> >>
> >> >> --- In m...@yahoogroups.com,
> =C3=83=C2=A5=C3=AF=C2=BF=C2=BD=C3=82=C2=B4=C3=83=C2=A6=C3=AF=C2=BF=C2=BD=
=C3=82=C2=A9=C3=83=C2=A6=C3=82=C2=B7=C3=82=C2=B3 wrote:
> >> >>> Hello all:
> >> >>>
> >> >>> I want to power off MSP430 completely when the battery is
> lower
> >> than a given
> >> >>> value, now I am using __low_power_mode_4() intrinsic
> command,
> >> but some
> >> >>> external IEs are active also. I know I can disable this
IEs
> by
> >> some extra
> >> >>> code, but dose any one know some easy ways to power it
of?
> >> >>>
> >> >>> --=20
> >> >>> Best Regards.
> >> >>> Chernwu
> >> >>>
> >> >>>
> >> >>> [Non-text portions of this message have been removed]
> >> >>>
> >> >=20
> >> >=20
> >> >=20
> >> >=20
> >> > ------------------------------------
> >> >=20
> >> >
> >> >=20
> >> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Can MSP430 be power off completely? - chernwu - Sep 24 21:59:16 2009
Thanks for you all, I feel so happy that all members here are so enthusiast=
ic.
I should described my question clearly, We are using a Wireless Sensor Netw=
ork, so when a node works incorrectly(such as the RF continually send Pream=
bles it will disturbing other node tranrecives and exhausts it's own batter=
y. So I only want to make this battery low node not to work until change it=
's battery and get a POR.
Thanks aschuh, I can disable all interrupt by clear the GIE bit.
--- In m...@yahoogroups.com, "aschuh" wrote:
>
>=20
> The easiest way is to clear the GIE Bit. But in this case only a POR or a=
PUC will reactivate the MSP430.
>=20
>=20
> --- In m...@yahoogroups.com, =E5=90=B4=E6=8B=A9=E6=B7=B3 wro=
te:
> >
> > Hello all:
> >=20
> > I want to power off MSP430 completely when the battery is lower than a =
given
> > value, now I am using __low_power_mode_4() intrinsic command, but some
> > external IEs are active also. I know I can disable this IEs by some ext=
ra
> > code, but dose any one know some easy ways to power it of?
> >=20
> > --=20
> > Best Regards.
> > Chernwu
> >=20
> >=20
> > [Non-text portions of this message have been removed]
>
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
ic.
I should described my question clearly, We are using a Wireless Sensor Netw=
ork, so when a node works incorrectly(such as the RF continually send Pream=
bles it will disturbing other node tranrecives and exhausts it's own batter=
y. So I only want to make this battery low node not to work until change it=
's battery and get a POR.
Thanks aschuh, I can disable all interrupt by clear the GIE bit.
--- In m...@yahoogroups.com, "aschuh"
>
>=20
> The easiest way is to clear the GIE Bit. But in this case only a POR or a=
PUC will reactivate the MSP430.
>=20
>=20
> --- In m...@yahoogroups.com, =E5=90=B4=E6=8B=A9=E6=B7=B3
te:
> >
> > Hello all:
> >=20
> > I want to power off MSP430 completely when the battery is lower than a =
given
> > value, now I am using __low_power_mode_4() intrinsic command, but some
> > external IEs are active also. I know I can disable this IEs by some ext=
ra
> > code, but dose any one know some easy ways to power it of?
> >=20
> > --=20
> > Best Regards.
> > Chernwu
> >=20
> >=20
> > [Non-text portions of this message have been removed]
>
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - OneStone - Sep 24 23:42:47 2009
Better to fix the problem, since it shouldn't do that anyway.
Al
chernwu wrote:
> Thanks for you all, I feel so happy that all members here are so enthusiastic.
>
> I should described my question clearly, We are using a Wireless Sensor Network, so when a node works incorrectly(such as the RF continually send Preambles it will disturbing other node tranrecives and exhausts it's own battery. So I only want to make this battery low node not to work until change it's battery and get a POR.
>
> Thanks aschuh, I can disable all interrupt by clear the GIE bit.
>
> --- In m...@yahoogroups.com, "aschuh" wrote:
>>
>> The easiest way is to clear the GIE Bit. But in this case only a POR or a PUC will reactivate the MSP430.
>> --- In m...@yahoogroups.com, 吴择淳 wrote:
>>> Hello all:
>>>
>>> I want to power off MSP430 completely when the battery is lower than a given
>>> value, now I am using __low_power_mode_4() intrinsic command, but some
>>> external IEs are active also. I know I can disable this IEs by some extra
>>> code, but dose any one know some easy ways to power it of?
>>>
>>> --
>>> Best Regards.
>>> Chernwu
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
> ------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Al
chernwu wrote:
> Thanks for you all, I feel so happy that all members here are so enthusiastic.
>
> I should described my question clearly, We are using a Wireless Sensor Network, so when a node works incorrectly(such as the RF continually send Preambles it will disturbing other node tranrecives and exhausts it's own battery. So I only want to make this battery low node not to work until change it's battery and get a POR.
>
> Thanks aschuh, I can disable all interrupt by clear the GIE bit.
>
> --- In m...@yahoogroups.com, "aschuh"
>>
>> The easiest way is to clear the GIE Bit. But in this case only a POR or a PUC will reactivate the MSP430.
>> --- In m...@yahoogroups.com, 吴择淳
>>> Hello all:
>>>
>>> I want to power off MSP430 completely when the battery is lower than a given
>>> value, now I am using __low_power_mode_4() intrinsic command, but some
>>> external IEs are active also. I know I can disable this IEs by some extra
>>> code, but dose any one know some easy ways to power it of?
>>>
>>> --
>>> Best Regards.
>>> Chernwu
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
> ------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Re: Can MSP430 be power off completely? - =?UTF-8?B?5ZC05oup5rez?= - Sep 24 23:49:59 2009
Hi OneStone :
Great suggestion, I find when the battery is lower than 2.3V, it will
continues send preambles. I think it's the low power problem so I want to
power it off.
I will find why the low battery make it continues send preambles, thanks
your advise:)
2009/9/25 OneStone
> Better to fix the problem, since it shouldn't do that anyway.
>
> Al
>
> chernwu wrote:
> > Thanks for you all, I feel so happy that all members here are so
> enthusiastic.
> >
> > I should described my question clearly, We are using a Wireless Sensor
> Network, so when a node works incorrectly(such as the RF continually send
> Preambles it will disturbing other node tranrecives and exhausts it's own
> battery. So I only want to make this battery low node not to work until
> change it's battery and get a POR.
> >
> > Thanks aschuh, I can disable all interrupt by clear the GIE bit.
> >
> > --- In m...@yahoogroups.com, "aschuh" wrote:
> >>
> >> The easiest way is to clear the GIE Bit. But in this case only a POR o=
r
> a PUC will reactivate the MSP430.
> >>
> >>
> >> --- In m...@yahoogroups.com, =C3=A5 =C2=B4=C3=A6=E2=80=B9=C2=A9=C3=
=A6=C2=B7=C2=B3 wrote:
> >>> Hello all:
> >>>
> >>> I want to power off MSP430 completely when the battery is lower than =
a
> given
> >>> value, now I am using __low_power_mode_4() intrinsic command, but som=
e
> >>> external IEs are active also. I know I can disable this IEs by some
> extra
> >>> code, but dose any one know some easy ways to power it of?
> >>>
> >>> --
> >>> Best Regards.
> >>> Chernwu
> >>>
> >>>
> >>> [Non-text portions of this message have been removed]
> >>>
> >
> >
> >
> >
> > ------------------------------------
> >
> >
> >
> >
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Great suggestion, I find when the battery is lower than 2.3V, it will
continues send preambles. I think it's the low power problem so I want to
power it off.
I will find why the low battery make it continues send preambles, thanks
your advise:)
2009/9/25 OneStone
> Better to fix the problem, since it shouldn't do that anyway.
>
> Al
>
> chernwu wrote:
> > Thanks for you all, I feel so happy that all members here are so
> enthusiastic.
> >
> > I should described my question clearly, We are using a Wireless Sensor
> Network, so when a node works incorrectly(such as the RF continually send
> Preambles it will disturbing other node tranrecives and exhausts it's own
> battery. So I only want to make this battery low node not to work until
> change it's battery and get a POR.
> >
> > Thanks aschuh, I can disable all interrupt by clear the GIE bit.
> >
> > --- In m...@yahoogroups.com, "aschuh"
> >>
> >> The easiest way is to clear the GIE Bit. But in this case only a POR o=
r
> a PUC will reactivate the MSP430.
> >>
> >>
> >> --- In m...@yahoogroups.com, =C3=A5 =C2=B4=C3=A6=E2=80=B9=C2=A9=C3=
=A6=C2=B7=C2=B3
> >>> Hello all:
> >>>
> >>> I want to power off MSP430 completely when the battery is lower than =
a
> given
> >>> value, now I am using __low_power_mode_4() intrinsic command, but som=
e
> >>> external IEs are active also. I know I can disable this IEs by some
> extra
> >>> code, but dose any one know some easy ways to power it of?
> >>>
> >>> --
> >>> Best Regards.
> >>> Chernwu
> >>>
> >>>
> >>> [Non-text portions of this message have been removed]
> >>>
> >
> >
> >
> >
> > ------------------------------------
> >
> >
> >
> >
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Can MSP430 be power off completely? - Stuart_Rubin - Sep 25 8:24:43 2009
We have occasions where we need to shut down our device completely in the e=
vent of an error. One thing I do is shut-down everything I can gracefully,=
disconnect the battery (which is connected to the MSP430 through a FET), d=
isable the watchdog, then go into an infinite "do nothing" loop.
The loop has two purposes: it makes sure that no other code is run after th=
e shut-down, and it drains any residual charge floating around the system i=
n capacitors, or wherever.
This helps guarantee that the device will only turn back on when we intend =
for it to.
Stuart
--- In m...@yahoogroups.com, "chernwu" wrote:
>
> Thanks for you all, I feel so happy that all members here are so enthusia=
stic.
>=20
> I should described my question clearly, We are using a Wireless Sensor Ne=
twork, so when a node works incorrectly(such as the RF continually send Pre=
ambles it will disturbing other node tranrecives and exhausts it's own batt=
ery. So I only want to make this battery low node not to work until change =
it's battery and get a POR.
>=20
> Thanks aschuh, I can disable all interrupt by clear the GIE bit.
>=20
> --- In m...@yahoogroups.com, "aschuh" wrote:
> >
> >=20
> > The easiest way is to clear the GIE Bit. But in this case only a POR or=
a PUC will reactivate the MSP430.
> >=20
> >=20
> > --- In m...@yahoogroups.com, =E5=90=B4=E6=8B=A9=E6=B7=B3 w=
rote:
> > >
> > > Hello all:
> > >=20
> > > I want to power off MSP430 completely when the battery is lower than =
a given
> > > value, now I am using __low_power_mode_4() intrinsic command, but som=
e
> > > external IEs are active also. I know I can disable this IEs by some e=
xtra
> > > code, but dose any one know some easy ways to power it of?
> > >=20
> > > --=20
> > > Best Regards.
> > > Chernwu
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
vent of an error. One thing I do is shut-down everything I can gracefully,=
disconnect the battery (which is connected to the MSP430 through a FET), d=
isable the watchdog, then go into an infinite "do nothing" loop.
The loop has two purposes: it makes sure that no other code is run after th=
e shut-down, and it drains any residual charge floating around the system i=
n capacitors, or wherever.
This helps guarantee that the device will only turn back on when we intend =
for it to.
Stuart
--- In m...@yahoogroups.com, "chernwu"
>
> Thanks for you all, I feel so happy that all members here are so enthusia=
stic.
>=20
> I should described my question clearly, We are using a Wireless Sensor Ne=
twork, so when a node works incorrectly(such as the RF continually send Pre=
ambles it will disturbing other node tranrecives and exhausts it's own batt=
ery. So I only want to make this battery low node not to work until change =
it's battery and get a POR.
>=20
> Thanks aschuh, I can disable all interrupt by clear the GIE bit.
>=20
> --- In m...@yahoogroups.com, "aschuh"
> >
> >=20
> > The easiest way is to clear the GIE Bit. But in this case only a POR or=
a PUC will reactivate the MSP430.
> >=20
> >=20
> > --- In m...@yahoogroups.com, =E5=90=B4=E6=8B=A9=E6=B7=B3
rote:
> > >
> > > Hello all:
> > >=20
> > > I want to power off MSP430 completely when the battery is lower than =
a given
> > > value, now I am using __low_power_mode_4() intrinsic command, but som=
e
> > > external IEs are active also. I know I can disable this IEs by some e=
xtra
> > > code, but dose any one know some easy ways to power it of?
> > >=20
> > > --=20
> > > Best Regards.
> > > Chernwu
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
RE: Re: Can MSP430 be power off completely? - Mike Stovall - Sep 25 8:56:40 2009
Hi Stuart,
I am just curious about turning off power completely. Is the event error
latch up?
=20
I have had trouble using the MSP430F437 as the processor latches up due
to transients which required the power to be removed to reset.
=20
When I was using the comparator input I found it most susceptible to
this latch up problem.=20
=20
Specifically SLYA014A - May 2000 addresses this issue.=20
=20
Thanks for the information on draining the system power forms to insure
the restart.
=20
Thanks,
Mike
=20
=20
=20
-----Original Message-----
From: m...@yahoogroups.com [mailto:m...@yahoogroups.com] On Behalf
Of Stuart_Rubin
Sent: Friday, September 25, 2009 5:24 AM
To: m...@yahoogroups.com
Subject: [msp430] Re: Can MSP430 be power off completely?
=20
=20=20
We have occasions where we need to shut down our device completely in
the event of an error. One thing I do is shut-down everything I can
gracefully, disconnect the battery (which is connected to the MSP430
through a FET), disable the watchdog, then go into an infinite "do
nothing" loop.
The loop has two purposes: it makes sure that no other code is run after
the shut-down, and it drains any residual charge floating around the
system in capacitors, or wherever.
This helps guarantee that the device will only turn back on when we
intend for it to.
Stuart
--- In msp430@yahoogroups. com,
"chernwu" wrote:
>
> Thanks for you all, I feel so happy that all members here are so
enthusiastic.
>=20
> I should described my question clearly, We are using a Wireless Sensor
Network, so when a node works incorrectly(such as the RF continually
send Preambles it will disturbing other node tranrecives and exhausts
it's own battery. So I only want to make this battery low node not to
work until change it's battery and get a POR.
>=20
> Thanks aschuh, I can disable all interrupt by clear the GIE bit.
>=20
> --- In msp430@yahoogroups. com,
"aschuh" wrote:
> >
> >=20
> > The easiest way is to clear the GIE Bit. But in this case only a POR
or a PUC will reactivate the MSP430.
> >=20
> >=20
> > --- In msp430@yahoogroups. com,
=E5=90=B4=E6=8B=A9=E6=B7=B3 wrote:
> > >
> > > Hello all:
> > >=20
> > > I want to power off MSP430 completely when the battery is lower
than a given
> > > value, now I am using __low_power_mode_4() intrinsic command, but
some
> > > external IEs are active also. I know I can disable this IEs by
some extra
> > > code, but dose any one know some easy ways to power it of?
> > >=20
> > > --=20
> > > Best Regards.
> > > Chernwu
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
>
[Non-text portions of this message have been removed]
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
I am just curious about turning off power completely. Is the event error
latch up?
=20
I have had trouble using the MSP430F437 as the processor latches up due
to transients which required the power to be removed to reset.
=20
When I was using the comparator input I found it most susceptible to
this latch up problem.=20
=20
Specifically SLYA014A - May 2000 addresses this issue.=20
=20
Thanks for the information on draining the system power forms to insure
the restart.
=20
Thanks,
Mike
=20
=20
=20
-----Original Message-----
From: m...@yahoogroups.com [mailto:m...@yahoogroups.com] On Behalf
Of Stuart_Rubin
Sent: Friday, September 25, 2009 5:24 AM
To: m...@yahoogroups.com
Subject: [msp430] Re: Can MSP430 be power off completely?
=20
=20=20
We have occasions where we need to shut down our device completely in
the event of an error. One thing I do is shut-down everything I can
gracefully, disconnect the battery (which is connected to the MSP430
through a FET), disable the watchdog, then go into an infinite "do
nothing" loop.
The loop has two purposes: it makes sure that no other code is run after
the shut-down, and it drains any residual charge floating around the
system in capacitors, or wherever.
This helps guarantee that the device will only turn back on when we
intend for it to.
Stuart
--- In msp430@yahoogroups.
"chernwu"
>
> Thanks for you all, I feel so happy that all members here are so
enthusiastic.
>=20
> I should described my question clearly, We are using a Wireless Sensor
Network, so when a node works incorrectly(such as the RF continually
send Preambles it will disturbing other node tranrecives and exhausts
it's own battery. So I only want to make this battery low node not to
work until change it's battery and get a POR.
>=20
> Thanks aschuh, I can disable all interrupt by clear the GIE bit.
>=20
> --- In msp430@yahoogroups.
"aschuh"
> >
> >=20
> > The easiest way is to clear the GIE Bit. But in this case only a POR
or a PUC will reactivate the MSP430.
> >=20
> >=20
> > --- In msp430@yahoogroups.
=E5=90=B4=E6=8B=A9=E6=B7=B3
> > >
> > > Hello all:
> > >=20
> > > I want to power off MSP430 completely when the battery is lower
than a given
> > > value, now I am using __low_power_mode_4() intrinsic command, but
some
> > > external IEs are active also. I know I can disable this IEs by
some extra
> > > code, but dose any one know some easy ways to power it of?
> > >=20
> > > --=20
> > > Best Regards.
> > > Chernwu
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
>
[Non-text portions of this message have been removed]
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Can MSP430 be power off completely? - Michael - Sep 25 13:21:11 2009
Thanks for the clarifications. I started programming MSPs with the Olimex E=
asyWeb II which uses a 149 part, but quickly made my own boards using 16x p=
arts so I didn't experience this issues since I didn't use the older parts =
for long (I also burned the 149 of the EasyWeb and replaced it with an 169)=
.
Regards,
Michael
--- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>
>=20=20
> It is exactly what I was talking about. Of course, as in any other
> case it is all about design.
> I also have seen MSP430 working from leakage current feed by
> transistors that were connected to anopther power supply.
> In low power mode the MSP430 could draw as little as10uA. A 10uF
> capacitor would supply this for 200ms with a drop of only 0.2V.
> Of course, if the CPU awake during this time the current drawn would
> be more, say 2mA. Even with this amount of current the 10uF capacitor
> will let the voltage drop 0.2V in 1ms. Again, since the MSP430=C2=B4s
> wake-up is around 6us the software will have much more than 1,000
> instructions to run (with 1MHz clock) before it notice the voltage is
> below the minimum - and at 1MHz the CPU can run till the voltage drops
> below 1.8V.
> In that leakage current case the CPU detected the low voltage the
> first time and entered in deep sleep. The leakage current went
> charging the bypass and feed capacitors (0.1uF + 10uF) till the point
> the MSP thought it was a power up. Then it drawn the current till the
> voltage droped again and entered in deep sleep. The process behaved
> like an oscilator.
> Like Al has written, it is not rocket science but demands some
> hardware - and software - knowledge to avoid pitfalls.
> One good way to avoid processor doing opperations it could not do,
> due the low voltage, would be to write in the FLASH a flag. It would
> say: the battery has run out (of course, doing it before it is too
> depleted to allow a reliable FLASH write). A checksum for this kind
> of flag is a must!
> Then after any RESET one thing to check is this flag - or the
> availability of good power - before allowing the software to do any
> serious job.
> -Augusto
> On Qui 24/09/09 19:10 , OneStone onestone@... sent:
> Michael the original 1121 and 149 parts were infamous for not fully=20
> powering down, and not recovering either. Once turned off even a
> very=20
> tiny amount of voltage in a cap would cause this, typically 0.4V was
>=20
> enough, and once the micro switched off its clocks and all its=20
> peripherals it draws next to nothing. The POR circuit of these parts
>=20
> didn't actually force the reset condition from there, and this is
> what I=20
> think Augusto was talking about. A lot of large caps (I have one
> design=20
> with a couple of 1500uF caps in it) can store enough make the micro=20
> think the button has been pressed again (potentially) but if you are
>=20
> aware of this it is easily solved.
> Al
> Michael wrote:
> > Augusto,
> >>> A simple method of doing this is to use a solid state switch
> with
> >>> a momentary push button to power on the circuit, that is
> activated
> >>> through one diode of a BAV70, the other diode is controlled from
> >>> the MSP.
> >>> When the button is pushed the MSP establishes the hold in signal
> >>> to maintain power to the circuit, when you want to turn
> >>> everything off the micro drops the signal. Depending on what
> else
> >>> is around a weak pull down may also be necessary
> >>> Al
> >=20
> >> Al, as you know turning off a low power device such as MSP430 is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes to=20
> >> RESET before the voltage is depleted enough.
> >=20
> > I don't understand how that could happen. The MSP is opening the
> relay, so voltage should only decrease to the point where #RESET will
> go active or Vcc will be too low. What would cause #RESET to go active
> and then inactive again while Vcc is decreasing but still over the
> minimum for operation?=20
> > Unless there is some high voltage circuit that will produce a high
> voltage discharge to Vcc while powering down, it doesn't make any
> sense to me. Or did you mean PUC or POR instead of the RESET pin?
> >=20
> >> One solution would be to switch off the power AND, at same time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> > That could easily be accomplished by using an SPDT relay:
> > NO : Vbat
> > COM: MSP Vcc
> > NC : GND (or discharge resistor to GND)
> > Of course, a mechanical monostable relay might consume too much
> during operation to make this a practical solution, unless you use a
> latching relay.
> >=20
> > Regards,
> > Michael K.
> >=20
> > --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
> >>=20=20
> >> Al, as you know turning off a low power device such as MSP430 is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes to
> RESET
> >> before the voltage is depleted enough. Of course it also depends
> on
> >> the software, a failed SVS processing scheme, MSP430 model
> (without
> >> SVS), consumption curve, etc.
> >> The trick is to avoid any kind of extra reset after the software
> has
> >> decided to go off.
> >> One solution would be to switch off the power AND, at same time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> >> MSP430 needs so low power to work that I would not be surprised
> if
> >> one could make it run with energy harvested from a radio antenna
> or
> >> even a finger touch...
> >> -Augusto
> >> On Qui 24/09/09 17:28 , OneStone onestone@ sent:
> >> A simple method of doing this is to use a solid state switch
> with a=20
> >> momentary push button to power on the circuit, that is activated
> >> through=20
> >> one diode of a BAV70, the other diode is controlled from the
> MSP.
> >> When=20
> >> the button is pushed the MSP establishes the hold in signal to
> >> maintain=20
> >> power to the circuit, when you want to turn everything off the
> micro
> >>
> >> drops the signal. Depending on what else is around a weak pull
> down
> >> may=20
> >> also be necessary
> >> Al
> >> old_cow_yellow wrote:
> >> > I think the OP did not want it to wake up at all.
> >> >=20
> >> > What is "power off completely"? Even LPM5 is not without
> power.
> >> >=20
> >> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> >> Chernwu,
> >> >> What do you mean by 'external IEs'?
> >> >>
> >> >> LPM4 will probably consume far less than the battery
> >> self-discharge, so LPM4 is probably a very good solution.
> >> >>
> >> >> If you want to completely shut off the MSP, you can use a
> voltage
> >> regulator with an enable pin like the TPS77001 or use a series
> fet.
> >> >>
> >> >> Your solution will greatly depend on how you intend to wake
> up
> >> the MSP after you 'turned it off'. In turn, this will depend on
> how
> >> the battery will be handled after the discharge condition
> (replace,
> >> in-circuit charging, DC input feeding the MSP while separately
> >> charging the battery, upon many others).
> >> >>
> >> >> Regards,
> >> >> Michael K.
> >> >>
> >> >> --- In m...@yahoogroups.com,
> =C3�=C2=A5=C3=AF=C2=BF=C2=BD=C3�=C2=B4=C3�=C2=A6=C3=
=AF=C2=BF=C2=BD=C3�=C2=A9=C3�=C2=A6=C3�=C2=B7=C3ᦙ=
3;=C2=B3 wrote:
> >> >>> Hello all:
> >> >>>
> >> >>> I want to power off MSP430 completely when the battery is
> lower
> >> than a given
> >> >>> value, now I am using __low_power_mode_4() intrinsic
> command,
> >> but some
> >> >>> external IEs are active also. I know I can disable this IEs
> by
> >> some extra
> >> >>> code, but dose any one know some easy ways to power it of?
> >> >>>
> >> >>> --=20
> >> >>> Best Regards.
> >> >>> Chernwu
> >> >>>
> >> >>>
> >> >>> [Non-text portions of this message have been removed]
> >> >>>
> >> >=20
> >> >=20
> >> >=20
> >> >=20
> >> > ------------------------------------
> >> >=20
> >> >
> >> >=20
> >> >
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
asyWeb II which uses a 149 part, but quickly made my own boards using 16x p=
arts so I didn't experience this issues since I didn't use the older parts =
for long (I also burned the 149 of the EasyWeb and replaced it with an 169)=
.
Regards,
Michael
--- In m...@yahoogroups.com, Augusto Einsfeldt
>
>=20=20
> It is exactly what I was talking about. Of course, as in any other
> case it is all about design.
> I also have seen MSP430 working from leakage current feed by
> transistors that were connected to anopther power supply.
> In low power mode the MSP430 could draw as little as10uA. A 10uF
> capacitor would supply this for 200ms with a drop of only 0.2V.
> Of course, if the CPU awake during this time the current drawn would
> be more, say 2mA. Even with this amount of current the 10uF capacitor
> will let the voltage drop 0.2V in 1ms. Again, since the MSP430=C2=B4s
> wake-up is around 6us the software will have much more than 1,000
> instructions to run (with 1MHz clock) before it notice the voltage is
> below the minimum - and at 1MHz the CPU can run till the voltage drops
> below 1.8V.
> In that leakage current case the CPU detected the low voltage the
> first time and entered in deep sleep. The leakage current went
> charging the bypass and feed capacitors (0.1uF + 10uF) till the point
> the MSP thought it was a power up. Then it drawn the current till the
> voltage droped again and entered in deep sleep. The process behaved
> like an oscilator.
> Like Al has written, it is not rocket science but demands some
> hardware - and software - knowledge to avoid pitfalls.
> One good way to avoid processor doing opperations it could not do,
> due the low voltage, would be to write in the FLASH a flag. It would
> say: the battery has run out (of course, doing it before it is too
> depleted to allow a reliable FLASH write). A checksum for this kind
> of flag is a must!
> Then after any RESET one thing to check is this flag - or the
> availability of good power - before allowing the software to do any
> serious job.
> -Augusto
> On Qui 24/09/09 19:10 , OneStone onestone@... sent:
> Michael the original 1121 and 149 parts were infamous for not fully=20
> powering down, and not recovering either. Once turned off even a
> very=20
> tiny amount of voltage in a cap would cause this, typically 0.4V was
>=20
> enough, and once the micro switched off its clocks and all its=20
> peripherals it draws next to nothing. The POR circuit of these parts
>=20
> didn't actually force the reset condition from there, and this is
> what I=20
> think Augusto was talking about. A lot of large caps (I have one
> design=20
> with a couple of 1500uF caps in it) can store enough make the micro=20
> think the button has been pressed again (potentially) but if you are
>=20
> aware of this it is easily solved.
> Al
> Michael wrote:
> > Augusto,
> >>> A simple method of doing this is to use a solid state switch
> with
> >>> a momentary push button to power on the circuit, that is
> activated
> >>> through one diode of a BAV70, the other diode is controlled from
> >>> the MSP.
> >>> When the button is pushed the MSP establishes the hold in signal
> >>> to maintain power to the circuit, when you want to turn
> >>> everything off the micro drops the signal. Depending on what
> else
> >>> is around a weak pull down may also be necessary
> >>> Al
> >=20
> >> Al, as you know turning off a low power device such as MSP430 is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes to=20
> >> RESET before the voltage is depleted enough.
> >=20
> > I don't understand how that could happen. The MSP is opening the
> relay, so voltage should only decrease to the point where #RESET will
> go active or Vcc will be too low. What would cause #RESET to go active
> and then inactive again while Vcc is decreasing but still over the
> minimum for operation?=20
> > Unless there is some high voltage circuit that will produce a high
> voltage discharge to Vcc while powering down, it doesn't make any
> sense to me. Or did you mean PUC or POR instead of the RESET pin?
> >=20
> >> One solution would be to switch off the power AND, at same time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> > That could easily be accomplished by using an SPDT relay:
> > NO : Vbat
> > COM: MSP Vcc
> > NC : GND (or discharge resistor to GND)
> > Of course, a mechanical monostable relay might consume too much
> during operation to make this a practical solution, unless you use a
> latching relay.
> >=20
> > Regards,
> > Michael K.
> >=20
> > --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
> >>=20=20
> >> Al, as you know turning off a low power device such as MSP430 is
> not
> >> an easy thing for who doesn't know much about hardware, and it
> seems
> >> to be the case of this OP.
> >> Any capacitor after the switch can hold the MSP running long
> enough
> >> to allow the CPU to turn the switch ON again in case it goes to
> RESET
> >> before the voltage is depleted enough. Of course it also depends
> on
> >> the software, a failed SVS processing scheme, MSP430 model
> (without
> >> SVS), consumption curve, etc.
> >> The trick is to avoid any kind of extra reset after the software
> has
> >> decided to go off.
> >> One solution would be to switch off the power AND, at same time,
> >> turn some output on to drain as many current as possible from
> >> decoupling and bypass capacitors around MSP430.
> >> MSP430 needs so low power to work that I would not be surprised
> if
> >> one could make it run with energy harvested from a radio antenna
> or
> >> even a finger touch...
> >> -Augusto
> >> On Qui 24/09/09 17:28 , OneStone onestone@ sent:
> >> A simple method of doing this is to use a solid state switch
> with a=20
> >> momentary push button to power on the circuit, that is activated
> >> through=20
> >> one diode of a BAV70, the other diode is controlled from the
> MSP.
> >> When=20
> >> the button is pushed the MSP establishes the hold in signal to
> >> maintain=20
> >> power to the circuit, when you want to turn everything off the
> micro
> >>
> >> drops the signal. Depending on what else is around a weak pull
> down
> >> may=20
> >> also be necessary
> >> Al
> >> old_cow_yellow wrote:
> >> > I think the OP did not want it to wake up at all.
> >> >=20
> >> > What is "power off completely"? Even LPM5 is not without
> power.
> >> >=20
> >> > --- In m...@yahoogroups.com, "Michael" wrote:
> >> >> Chernwu,
> >> >> What do you mean by 'external IEs'?
> >> >>
> >> >> LPM4 will probably consume far less than the battery
> >> self-discharge, so LPM4 is probably a very good solution.
> >> >>
> >> >> If you want to completely shut off the MSP, you can use a
> voltage
> >> regulator with an enable pin like the TPS77001 or use a series
> fet.
> >> >>
> >> >> Your solution will greatly depend on how you intend to wake
> up
> >> the MSP after you 'turned it off'. In turn, this will depend on
> how
> >> the battery will be handled after the discharge condition
> (replace,
> >> in-circuit charging, DC input feeding the MSP while separately
> >> charging the battery, upon many others).
> >> >>
> >> >> Regards,
> >> >> Michael K.
> >> >>
> >> >> --- In m...@yahoogroups.com,
> =C3�=C2=A5=C3=AF=C2=BF=C2=BD=C3�=C2=B4=C3�=C2=A6=C3=
=AF=C2=BF=C2=BD=C3�=C2=A9=C3�=C2=A6=C3�=C2=B7=C3ᦙ=
3;=C2=B3 wrote:
> >> >>> Hello all:
> >> >>>
> >> >>> I want to power off MSP430 completely when the battery is
> lower
> >> than a given
> >> >>> value, now I am using __low_power_mode_4() intrinsic
> command,
> >> but some
> >> >>> external IEs are active also. I know I can disable this IEs
> by
> >> some extra
> >> >>> code, but dose any one know some easy ways to power it of?
> >> >>>
> >> >>> --=20
> >> >>> Best Regards.
> >> >>> Chernwu
> >> >>>
> >> >>>
> >> >>> [Non-text portions of this message have been removed]
> >> >>>
> >> >=20
> >> >=20
> >> >=20
> >> >=20
> >> > ------------------------------------
> >> >=20
> >> >
> >> >=20
> >> >
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