In part 3 we integrated the reduced standard C library (newlib-nano) and set up printf()to output characters over UART. Up until now, we have built the project using make and we have configured the peripherals with direct register access. This works perfectly fine, but as our project grows, we may benefit from using a more…
Category: Embedded C
STM32 without CubeIDE (Part 3): The C Standard Library and printf()
In part 2 we wrote a Makefile to build the project, configured the system clock and created a basic blink application. So far, we have built the project without the C standard library by invoking gcc with the -nostdlib flag. In this article we are going to take a look at how to integrate the C standard library into our project and set up printf() to send messages to our host machine via UART for some primitive debugging capabilities.
Calling C code from Python
The majority of all firmware is written in C (or C++), but for writing small utility and automation scripts on the host machine, Python is usually the go-to language. I was recently presented with the problem of running some of our firmware algorithms on a set of pre-recorded data, as part of our suite of automation scripts written in Python. Instead of translating the C code to Python – which could quickly become a maintenance nightmare – I opted for creating an interface so the C code could be called directly from a Python script. Luckily, Python has plenty of support for this.
Project Smart Greenhouse (Part 2): Data collection with ESP32
In part 1 I presented the general idea for the Smart Greenhouse. In this part I am going to get my ESP32 development board up and running and start logging some data to an online database.
Unit testing in STM32CubeIDE with GoogleTest
Unit testing has become an essential part of developing high-quality, reliable and maintainable software, but is not as commonplace in the firmware industry as it ought to be. If you are tired of being slowed down by the “build-flash-debug” style of development, waiting for hardware or having to share hardware with several other coworkers, then off-target unit testing and test-driven development is for you!
Interfaces in C
Interfaces are an extremely useful tool to develop loosely-coupled, testable software. In the embedded world it will even allow us to write firmware and run it on our development PC instead of the actual hardware, which may be scarce or not even produced yet.
Multiple instances of a module in C
When writing modules for your application, sometimes it might be enough to have just a single instance of the module (e.g. a global “logging” module), but oftentimes you will need to create multiple instances of a module (e.g. a “queue” module). In this article I will take a look at various ways to implement this in C.
The ‘volatile’ qualifier
When programming embedded systems in C, you will most likely have stumbled upon the volatile keyword in a variable declaration. But what does this actually mean – and when should you use it?