Martin Cowen ⁽⁴⁵⁾

When trying to write code samples in front of someone else, for example during an interview, it's a good idea to start by writing down the steps required before converting those to code. Instead of writing them down just as a list, format them as comments with blank lines in between to make filling out the code easier. int main(void) { // fizz buzz example: // test integers in range 0 to 100 // print fizzbuzz if divisible by 3 and 5 // print fizz if divisible by 3 only // print buzz if divisible by 5 only // if none of the above conditions, just print the number } It's much easier to debug the algorithm or design by rearranging and changing those comment lines than by changing the code once you're committed to all the details - variable…

Picking up someone else's design to get it into production is a common enough situation and yet there are always interesting problems to be solved. These can get particularly challenging if that previous engineer has left the company and was the only one who really knew how the product worked. In this case, not only was it a new product, it was the first product of a new range using a new processor and new communications protocol, which we were going to develop into many more variants. So it was inevitable that there would be some bugs found by the first customers. Of course the product worked fine on the bench - it was when multiple products were wired together in the field that the bug showed up. Although as a product manufacturer we specified how the field wiring was…

Given that the promise of STM32CubeIDE is that adding functionality should be as easy as clicking in checkboxes, you'd think it would be easy to set up Ethernet on one of STM's own Nucleo boards which is designed for it, and to get it responding to ping on your internal network at a fixed IP address within minutes. If so, you've been misled by the way that simpler interfaces such as UART, SPI, I2C, and GPIO are easily configured with STM32CubeIDE/CubeMX, especially if you don't need to have them working through DMA. Because of the high speed nature of Ethernet, it is essential to use DMA and to get the caching set up right, and until you do, it doesn't work at all. Unlike UART, SPI, I2C or CAN, you can't just start with the simpler case of transmit-only to…

Reusability is an idea often touted in software, and embedded projects are no exception. In fact, the reasons for needing re-usability or ease of porting are often more pertinent to embedded projects even though the initial use-case doesn't call for them, and speed to market is usually business-critical. Why would the processor (or microcontroller) change after it has been designed-in? After all, the hardware designer has to make lots of decisions which are tied to that specific processor in that specific package, so it would be a lot of work for them to change it. Timescales for embedded projects often require the code to be in progress whilst the hardware is being finalised, PCB laid out and prototypes produced. If we can't start the driver layers until the prototypes are available, then it becomes risky to work on the aspects…

Code generation from ioc STM32CubeIDE is a powerful piece of software, including code generation from a GUI formerly known as CubeMX, a code editing environment and a full debugger. The code generation feature should not be dismissed as a beginner level gimmick because it can be used within a professional environment, saving a huge effort compared to doing that work yourself, when you know how to keep it under control. If you're not aware of how to keep the code generator under control, you could lose code, be unable to get your code where you need it in the files, and feel restricted by it's imposed code structure. The CubeMX part of STM32CubeIDE can be used as a standalone application or integrated into the IDE and uses the [project name].ioc file to store the configuration of the peripherals, drivers and…