nRF5 to nRF Connect SDK migration via DFU over BLE
This writeup contains some notes on how I was able to migrate one of my clients projects based on the nRF5 SDK, to nRF Connect SDK (NCS) based firmware, via a DFU to devices in the field over BLE.
Getting Started With Zephyr: Devicetrees
This blog post provides an introduction to the "Devicetree", another unique concept in The Zephyr Project. We learn about the basic syntax of a device tree and how its structure and hierarchy mirror hardware, from the SoC to the final board. We also see how hardware described in a devicetree can be referenced and controlled in the source code of a Zephyr-based application.
Bellegram, a wireless DIY doorbell that sends you a Telegram message
A wireless button that uses the M5 STAMP PICO and Mongoose to send a Telegram message when pressed. The code is written in C
Getting Started with (Apache) NuttX RTOS Part 2 - Looking Inside and Creating Your Customized Image
In the previous article (https://www.embeddedrelated.com/showarticle/1524.p...) we saw how to run NuttX RTOS using the SIMulator. Today we will see how NuttX's directory tree is organized and how to use the menuconfig to enable some applications, including some tricks to search and solve dependencies.
NuttX Directories organization:
If you have previously compiled the Linux kernel or the U-Boot bootloader you will see that the NuttX source tree organization is...
Getting Started With Zephyr: West Manifest Customization
IntroductionThe Zephyr Project RTOS (https://zephyrproject.org/), or simply “Zephyr” as it is known colloquially, is an increasingly popular real-time operating system due to its native support for over 450 boards and countless peripherals. When starting with any embedded software project, the first task is to start from a known baseline. This can include cloning a repository from source control, which can be the case with embedded Linux, or downloading a zip file representing a...
Cracking the (embedded) Coding Interview
You never forget the day you land your first job.
The thrill of receiving that call from your recruiter to tell you that you bagged your dream role! The relief when you finally see the offer letter you’ve been working towards for years. The pride in your parents' voices when you call home and say “Hey look Ma, I’ve made it!”
But before that, there’s the grueling screening process to get through. Tech interviews often last up to three months and companies can have five...
Absolute Beginner's Guide To Getting Started With Raspberry Pi
Contents:
- Introduction
- Simplifications
- Decisions
- The Raspberry Pi
- Parts: What You Need
- Suppliers: Where To Order
- Shopping Lists: What To Order
Embedded Programming Video Course Shows How OOP Works Under the Hood
If you'd like to understand how Object-Oriented Programming (OOP) really works under the hood, here is a free video course for you:
OOP part-1: Encapsulation: This first lesson on Object-Oriented Programming (OOP) introduces the concept of Encapsulation, which is the ability to package data and functions together into classes. You'll see how you can emulate Encapsulation in C, what kind of code is generated, and how to debug such code. Next, you will translate the C design into C++ using...
Linux Kernel Development - Part 1: Hello Kernel!
Our very first program in every language or framework usually is the notorious "Hello World" program. For this Linux Kernel Modules Development introduction we will follow the same concept, but instead of the usual "Hello World" we will make a "Hello Kernel!" and you will understand the reason in a few moments. Note that in this article I will not focus on a deep explanation about this topic for the moment, since this is only the introduction.
But before we dive into code we need to have the...
Making a connection 1
In order for your system to control devices, you must be able to connect it to those devices.
Besides different sizes based on wire size, there are a few different styles of connectors that can be used. There are also weather-resistant terminals that can be used if needed.
Ring
(Parks, 16)
- used for circuits that you don’t want to become easily disconnected
- ground wire attached to a stud
Push-On
- can be used on relay terminals
(Parks, 18)
- could be...
MSP430 Launchpad Tutorial - Part 2 - Interrupts and timers
What is an "interrupt"? It is a signal that informs our MCU that a certain event has happened, causing the interruption of the normal flow of the main program and the execution of an "interrupt routine", that handles the event and takes a specified action.
Interrupts are essential to avoid wasting the processor's valuable time in polling loops, waiting for external events (in fact they are used in Real-Time Operating Systems,
Introduction to Microcontrollers - Driving WS2812 RGB LEDs
This tutorial chapter is a bit of a detour, but I think an interesting and useful one. It introduces a bit of assembly language programming, and demonstrates bit-banging a tight serial data protocol. And it deals with RGB LEDs, which are just very fun in their own right, especially these new parts. So I thought I'd post this to give readers time for some holiday lighting experimenting.
Back To The FutureRemember how we started this...
VHDL tutorial - A practical example - part 3 - VHDL testbench
In part 1 of this series we focused on the hardware design, including some of the VHDL definitions of the I/O characteristics of the CPLD part. In part 2, we described the VHDL logic of the CPLD for this design. In part 3, we will show the entire VHDL design and the associated tests used to prove that we have, in fact, designed what we started out to design.
First, let's pull all of the pieces of the prior design together into a...
VHDL tutorial - A practical example - part 2 - VHDL coding
In part 1 of this series we focused on the hardware design, including some of the VHDL definitions of the I/O characteristics of the CPLD part. In part 2, we will describe the VHDL logic of the CPLD for this design.
With any design, the first step to gather the requirements for the job at hand. From part 1 of this article, I have copied two sections that address some of the requirements for the CPLD design.
The data acquisition engine has the...
VHDL tutorial - A practical example - part 1 - Hardware
In previous posts I described some simple VHDL examples. This time let's try something a little more complex. This is part one of a multiple part article. This is intended to be a detailed description of one of several initial designs that I developed for a client. This design never made it into a product, but a similar design was used and is currently being produced. As a considerable amount of work was put into this effort, I decided to share this design...
VHDL tutorial - Creating a hierarchical design
In earlier blog entries I introduced some of the basic VHDL concepts. First, developing a function ('VHDL tutorial') and later verifying and refining it ('VHDL tutorial - part 2 - Testbench' and 'VHDL tutorial - combining clocked and sequential logic'). In this entry I will describe how to...
Getting Started With Zephyr: West Manifest Customization
IntroductionThe Zephyr Project RTOS (https://zephyrproject.org/), or simply “Zephyr” as it is known colloquially, is an increasingly popular real-time operating system due to its native support for over 450 boards and countless peripherals. When starting with any embedded software project, the first task is to start from a known baseline. This can include cloning a repository from source control, which can be the case with embedded Linux, or downloading a zip file representing a...
Endianness and Serial Communication
Endianness is a consideration that is easily overlooked in the design of embedded systems. I myself am amply guilty of this oversight. It’s something you don’t ever have to worry about if you’re only working with a single processor or two processors that have the same endianness. You can even avoid it if you have two processors that have different endianness but never transmit data between themselves that consists of more than one byte. It’s easy to lull...
VHDL tutorial - part 2 - Testbench
In an earlier article I walked through the VHDL coding of a simple design. In this article I will continue the process and create a test bench module to test the earlier design. The Xilinx ISE environment makes it pretty easy to start the testing process. To start the process, select "New Source" from the menu items under "Project". This launches the "New Source Wizard". From within the Wizard select "VHDL Test Bench" and enter the name of the new module (click 'Next' to...
MSP430 LaunchPad Tutorial - Part 4 - UART Transmission
Today we are going to learn how to communicate using UART with the Launchpad. For this purpose I will replace the default microcontroller that comes with the board with the MSP430G2553. It is the most powerful device in the MSP430 Value Line and it comes with an integrated hardware UART module, along with 16 Kb of Flash memory, 512 bytes of SRAM and an 8-channel, 10 bit ADC.
UART communication can be useful when dealing with sensors: as a basic example, we could...
MSP430 LaunchPad Tutorial - Part 3 - ADC
In this new episode of our journey into MSP430 I will explain the basics of Analog to Digital Conversion on the MSP430G2231.We will write a program that will read an ADC channel and will toggle some leds based on the result of the conversion.
We start as usual with the inclusion of the header file for the MSP430G2231, the leds stuff and with the definition of a variable that will store the result of the conversion. We also declare a function that will initialize the ADC...
Introduction to Microcontrollers - Interrupts
It's Too Soon To Talk About Interrupts!That, at least, could be one reaction to this chapter. But over the years I've become convinced that new microcontroller programmers should understand interrupts before being introduced to any complex peripherals such as timers, UARTs, ADCs, and all the other powerful function blocks found on a modern microcontroller. Since these peripherals are commonly used with interrupts, any introduction to them that does not...
Introduction to Microcontrollers - Hello World
Embedded Hello WorldA standard first program on an embedded platform is the blinking LED. Getting an LED to blink demonstrates that you have your toolchain set up correctly, that you are able to download your program code into the μC, and that the μC and associated circuitry (e.g. the power supply) is all working. It can even give you good evidence as to the clock rate that your microcontroller is running (something that trips up a great many people,...
C++ on microcontrollers 1 - introduction, and an output pin class
This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers. Reader input is very much appreciated, you might even steer me in the direction you find most interesting.
I am lazy. I am also a programmer. Luckily, being a lazy...
VHDL tutorial - A practical example - part 2 - VHDL coding
In part 1 of this series we focused on the hardware design, including some of the VHDL definitions of the I/O characteristics of the CPLD part. In part 2, we will describe the VHDL logic of the CPLD for this design.
With any design, the first step to gather the requirements for the job at hand. From part 1 of this article, I have copied two sections that address some of the requirements for the CPLD design.
The data acquisition engine has the...
Introduction to Microcontrollers - Timers
Timers - Because "When" MattersComputer programs are odd things, for one reason because they have no concept of time. They may have the concept of sequential execution, but the time between instructions can be essentially any number and the program won't notice or care (unless assumptions about time have been built into the program by the programmer). But the real world is not like this. In the real world, especially the real embedded world,...
Endianness and Serial Communication
Endianness is a consideration that is easily overlooked in the design of embedded systems. I myself am amply guilty of this oversight. It’s something you don’t ever have to worry about if you’re only working with a single processor or two processors that have the same endianness. You can even avoid it if you have two processors that have different endianness but never transmit data between themselves that consists of more than one byte. It’s easy to lull...
VHDL tutorial - Creating a hierarchical design
In earlier blog entries I introduced some of the basic VHDL concepts. First, developing a function ('VHDL tutorial') and later verifying and refining it ('VHDL tutorial - part 2 - Testbench' and 'VHDL tutorial - combining clocked and sequential logic'). In this entry I will describe how to...
Byte and Switch (Part 1)
Imagine for a minute you have an electromagnet, and a microcontroller, and you want to use the microcontroller to turn the electromagnet on and off. Sounds pretty typical, right?We ask this question on our interviews of entry-level electrical engineers: what do you put between the microcontroller and the electromagnet?We used to think this kind of question was too easy, but there are a surprising number of subtleties here (and maybe a surprising number of job candidates that were missing...
Introduction to Microcontrollers - Further Beginnings
Embedded Programming BasicsThis tutorial entry will discuss some further embedded programming basics that you will need to understand before proceeding on to the LED blinky and other example programs. We will do this by looking at the general organization and types of instructions found in most microcontrollers, and how that organization and those instructions are reflected (or, in some cases, ignored) by the C programming language.
Basic CPU...
