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Small MSP430 with UART?

Started by merapcb January 19, 2011
Hi. I am looking for a small and cheap ($2-3) MSP with a single UART but all I can find seem to have just I2C/SPI (or I am not searching the TI site correctly). What would be a good choice? The requirements are very simple as follows:
- Single UART (for serial comm)
- 10 I/Os
- Speed not important, no PWM/ADC/etc

Of course, they need to be largely available on Farnell etc. and with samples available from TI......

Thanks

Beginning Microcontrollers with the MSP430

On 1/19/2011 6:51 AM, merapcb wrote:
>
> Hi. I am looking for a small and cheap ($2-3) MSP with a single UART but all I can find seem to have just I2C/SPI (or I am not searching the TI site correctly). What would be a good choice? The requirements are very simple as follows:
> - Single UART (for serial comm)
> - 10 I/Os
> - Speed not important, no PWM/ADC/etc
>
> Of course, they need to be largely available on Farnell etc. and with samples available from TI......

If cost and availability are a concern (large volume project), consider
the smallest MSP that has sufficient I/O & code space and use the timer
to implement a software UART.

Regards
-Bill Knight
R O SoftWare
--- In m..., Bill Knight wrote:

> > Of course, they need to be largely available on Farnell etc. and with samples available from TI......
>
> If cost and availability are a concern (large volume project), consider
> the smallest MSP that has sufficient I/O & code space and use the timer
> to implement a software UART.
>

Yes I thought of bit banging the UART while looking at the F11x series but basically prefer not to do it (don't know why, maybe it's so straight forward). Regarding quantities, no, it is not mass produced and that is why I have to rely on it basically being available from the online vendors.

I have used Timer A on F1XX, F2xxx and F5xxx devices to implement a third UART. The only real problem that I have had is that you get one interrupt per bit transferred in either direction. This limits the baud rate that the processor can handle. I generally use a ~4MHz clock as the timer source and 9600 baud data rates without any problems.

Ian

From: m... [mailto:m...] On Behalf Of merapcb
Sent: 19 January 2011 13:13
To: m...
Subject: [msp430] Re: Small MSP430 with UART?

--- In m..., Bill Knight wrote:

> > Of course, they need to be largely available on Farnell etc. and with samples available from TI......
>
> If cost and availability are a concern (large volume project), consider
> the smallest MSP that has sufficient I/O & code space and use the timer
> to implement a software UART.
>

Yes I thought of bit banging the UART while looking at the F11x series but basically prefer not to do it (don't know why, maybe it's so straight forward). Regarding quantities, no, it is not mass produced and that is why I have to rely on it basically being available from the online vendors.



On 19/01/2011 12:51, merapcb wrote:
>
> Hi. I am looking for a small and cheap ($2-3) MSP with a single UART but all I can find seem to have just I2C/SPI (or I am not searching the TI site correctly). What would be a good choice? The requirements are very simple as follows:
> - Single UART (for serial comm)
> - 10 I/Os
> - Speed not important, no PWM/ADC/etc
>
> Of course, they need to be largely available on Farnell etc. and with samples available from TI......
I'd use a PIC for that sort of application.

Leon
--
Leon Heller
G1HSM
--- In m..., Leon Heller wrote:

>
> I'd use a PIC for that sort of application.
>

True, or a 8051 derivative. But for the moment I sort of want/have to stick to the MSP toolchain.

On 19/01/2011 13:44, merapcb wrote:
> --- In m..., Leon Heller wrote:
>
>>
>> I'd use a PIC for that sort of application.
>> True, or a 8051 derivative. But for the moment I sort of want/have to stick to the MSP toolchain.
It wwould be more sensible to choose the ideal device for the
application. I'd use the 14-pin 16F1823:

http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en544838

It's an XLP device with equivalent power consumption to the MSP430, and
is under $1 in quantity.

Leon
--
Leon Heller
G1HSM
The F2xx series is generally cheaper than the F1xx, and has better DCO
stability, especially on the so called calibrated frequencies. The G2xx
series now goes to 8k flash, but is limited by a single calibrated
frequency. Using the calibrated frequencies of the DCO I find that you
can reliably communicate at much higher baud rates even when bit
banging. Bit banging uses very little code space, and you can easily
implement full duplex if you need to, it depends on how much other code
you need to deal with, other than the comms routines as to whether you
could fit into a 8k device. The G2452 top of the range G2xxx series is
listed at $2.45 single quantities on Digikey, but, as usual, neither
Digikey nor Mouser has any stock.

Cheers

Al

The smallest device with a hardware UART is the 2132

On 19/01/2011 11:21 PM, merapcb wrote:
> Hi. I am looking for a small and cheap ($2-3) MSP with a single UART but all I can find seem to have just I2C/SPI (or I am not searching the TI site correctly). What would be a good choice? The requirements are very simple as follows:
> - Single UART (for serial comm)
> - 10 I/Os
> - Speed not important, no PWM/ADC/etc
>
> Of course, they need to be largely available on Farnell etc. and with samples available from TI......
>
> Thanks
>
Hi,

if I read it correctly, the F2112 has an UART too.
It is cheaper and available at Farnell/Digikey.

Regards

Dirk

Am 19.01.2011 15:12, schrieb OneStone:
>
> The F2xx series is generally cheaper than the F1xx, and has better DCO
> stability, especially on the so called calibrated frequencies. The G2xx
> series now goes to 8k flash, but is limited by a single calibrated
> frequency. Using the calibrated frequencies of the DCO I find that you
> can reliably communicate at much higher baud rates even when bit
> banging. Bit banging uses very little code space, and you can easily
> implement full duplex if you need to, it depends on how much other code
> you need to deal with, other than the comms routines as to whether you
> could fit into a 8k device. The G2452 top of the range G2xxx series is
> listed at $2.45 single quantities on Digikey, but, as usual, neither
> Digikey nor Mouser has any stock.
>
> Cheers
>
> Al
>
> The smallest device with a hardware UART is the 2132
>
> On 19/01/2011 11:21 PM, merapcb wrote:
> > Hi. I am looking for a small and cheap ($2-3) MSP with a single UART
> but all I can find seem to have just I2C/SPI (or I am not searching
> the TI site correctly). What would be a good choice? The requirements
> are very simple as follows:
> > - Single UART (for serial comm)
> > - 10 I/Os
> > - Speed not important, no PWM/ADC/etc
> >
> > Of course, they need to be largely available on Farnell etc. and
> with samples available from TI......
> >
> > Thanks
> >
> >
> >
> >
> >
> >
> >
> >
> >
The F2112 costs US$2.20 in 250 lots from Digikey and AUS$2.56/100 from
farnell, vs US$0.84 for the superior spec'd G2432 in 250 lots from Mouser.

Al

On 20/01/2011 2:14 AM, Dirk Rapp wrote:
> Hi,
>
> if I read it correctly, the F2112 has an UART too.
> It is cheaper and available at Farnell/Digikey.
>
> Regards
>
> Dirk
>
> Am 19.01.2011 15:12, schrieb OneStone:
>> The F2xx series is generally cheaper than the F1xx, and has better DCO
>> stability, especially on the so called calibrated frequencies. The G2xx
>> series now goes to 8k flash, but is limited by a single calibrated
>> frequency. Using the calibrated frequencies of the DCO I find that you
>> can reliably communicate at much higher baud rates even when bit
>> banging. Bit banging uses very little code space, and you can easily
>> implement full duplex if you need to, it depends on how much other code
>> you need to deal with, other than the comms routines as to whether you
>> could fit into a 8k device. The G2452 top of the range G2xxx series is
>> listed at $2.45 single quantities on Digikey, but, as usual, neither
>> Digikey nor Mouser has any stock.
>>
>> Cheers
>>
>> Al
>>
>> The smallest device with a hardware UART is the 2132
>>
>> On 19/01/2011 11:21 PM, merapcb wrote:
>>> Hi. I am looking for a small and cheap ($2-3) MSP with a single UART
>> but all I can find seem to have just I2C/SPI (or I am not searching
>> the TI site correctly). What would be a good choice? The requirements
>> are very simple as follows:
>>> - Single UART (for serial comm)
>>> - 10 I/Os
>>> - Speed not important, no PWM/ADC/etc
>>>
>>> Of course, they need to be largely available on Farnell etc. and
>> with samples available from TI......
>>> Thanks
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>