For an university research project we are implementing a software simulator for the EZH (or SmartDMA) co-prozessor present on some NXP MCUs.
This article describes how to setup and build QEMU in a docker container, including debugging QEMU with VS Code.
Continue readingToday’s projects and systems get more and more complex. Many systems include multiple MCUs, connected with a field bus or network, for example CAN. For example there can be up to 70 CAN nodes in modern cars. Such larger and connected systems are a challenge for debugging.
Traditional hardware debugging requires a hardware debug probe, connected with a dedicated SWD/JTAG debug cable to the target device. This needs dedicated pins on the target device plus physical access to the device itself. In many cases, this is not possible in the final product. The hardware debug probes, cables, pins and high speed signals are costly. And worse they can introduce new problems and are prone to interference.
If there is a field bus like CAN connecting all the MCUs, why not use it for hardware debugging? Hardware debugging meaning programming the FLASH memory, halt the MCU, inspect the memory and registers, and step through the code?
Yes, we can! With the help of a rather unknown hardware feature on ARM Cortex-M devices. We can use the ARM DebugMonitor Interrupt to control and debug the target system. As we would use a JTAG/SWD connection. Instead, we use the CAN bus :-).
Continue readingThe NXP SDK is git based which is great. If I create a project with VS code, it references the SDK cloned locally.
A standalone project structure is needed if you want to easily share a project with your team. It’s also necessary for sharing inside a classroom environment. This article shows how to use an NXP SDK project in standalone mode.
Continue readingIn CI/CD for Embedded with VS Code, Docker and GitHub Actions, I used GitHub to build a pipeline. This setup supports continuous integration within a CI/CD environment.
This time, let’s do a similar thing. But instead of GitHub, I use GitLab with VS Code. And I use it for a project where three different MCUs are used: the Raspberry Pi Pico-W, an Espressif ESP32 plus the NXP K22FX512 on the Sumo robot:
Europe is currently facing an ‘Energy Crisis,’ and ‘Sustainability’ is a popular topic among companies. However, embedded engineers go beyond talking—they take action and make tangible changes in the world. With the increasing use of electronic devices, minimizing their energy and power consumption is crucial. Optimizing systems for deep low power or deep low energy is a challenging task. Nonetheless, as I will demonstrate in this article, it is possible to reduce energy consumption by a factor of 100 or more. This article provides a brief overview of the foundational concepts and then applies them step-by-step to an ARM Cortex microcontroller.
Float and double data types area a bad choice for embedded applications. At least in most applications, and can or should be avoided, even with hardware FPU support present.
But how can I be sure that no floating point operations are used?
This article describes how to configure the GNU toolchain, so that no float or double operations are used, with the example of ARM Cortex-M. What I do? ‘Poisoning’ (!!!) the source code, force the gcc compiler to use software floating point operations and then catch them with the GNU linker :-).
Continue readingThe ‘Verkehrshaus der Schweiz‘, the ‘Swiss Museum of Transport’ is Switzerland’s most popular museum.
In April 2023, it opened up a new building and the ‘Experience Energy!’ exhibition. For the opening event we created a unique construction kit to explore energy: from harvesting to storing and up to distributing and using energy.
An important part of every CI/CD pipeline is having a testing phase. In this article I show how to use GNU gcov (coverage) with an embedded target, using Visual Studio Code as front end:
With this, I can run the code on the embedded target which stores the coverage data on the host.
Continue readingIn the OOP world, global objects get initialized with a constructor and destroyed at the end with a destructor. Interestingly, the GNU gcc has attributes to mark functions as constructor and destructors, which can greatly simply system startup and shutdown, even if not using C++.
With the GNU gcc compiler, I can mark functions with an attribute, so they get called before entering main() or after exit of main(). The attribute works both in C and C++, but it especially useful in C to initialize modules in an automated way.
Continue readingDeveloping for an embedded target means using a certain version of GNU compiler, debugger and other tools. The challenge gets bigger if working with multiple different tool chains and environments.
Conda is package, dependency and environment management tool. While it is heavily used for Python and Data Science development, it is surprisingly working very well to set up and managing environments for embedded development. Conda is great for managing non-Python dependencies and setups.
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MCU on Eclipse 