Amazon has released in the past week the FreeRTOS version V10.4.0. Time to upgrade, actually the most recent version 10.4.1! The same time the SEGGER SystemView V3.12 was released back in April this year. No surprise: with the FreeRTOS changes they don’t work out of the box: but no worries, I have you covered and applied all the needed patches and changes to have them working again together: the latest FreeRTOS v10.4.x with Segger SystemView v3.12:
As a VCS (Version Control System) I’m using git in all my projects. And not only for software or firmware projects: I’m using it for hardware design (KiCAD, FreeCAD, …) or for documentation (LaTeX, …) too.
The nice thing with the Eclipse IDE is that it supports nice git integration, making importing projects from git repositories easy.
COVID-19 is by far not over, and in Switzerland the infection rate is going up again (2nd wave?). During the spring 2020 semester university lock-down we moved pretty much everything to a ‘distance learning’ setup. With that experience and with the request to prepare for the fall semester, I have constructed a DIY conference and teaching device which should make things simpler and easier: a combination of video camera, speaker phone and a muting device:
At the university the end of a semester means that you have to get ready for the next semester. I always tend to use the latest and greatest tools for the labs. This week I received the notification that a new version of the Eclipse based MCUXpresso IDE is available, time to check it out for the next semester.
Creating a new project with Eclipse for a microcontroller these days is fairly easy, and I have the choice if I want to start the project with C or C++:
Choice of C and C++ for a new project
Still the embedded microcontroller world is dominated by C and not C++. So while it is easy to start with a C++ project, most vendor provided example or tutorial project are C projects. So how can I transform such project to C++?
This is a follow-up article of my earlier project presented in “FatFS, MinIni, Shell and FreeRTOS for the NXP K22FN512“. I wanted to extend it with a USB MSD (memory stick) device: The USB storage device gets automatically mounted, and depending on a configuration (.ini) file on the memory device I can perform various actions, for example automatically copy data from the SD card to the USB device. For example the system logs data, and to get the data I insert the memory stick, it copies the data on it and automatically unmounts it, and I can remove the memory stick.
The NMI is a special interrupt on ARM Cortex-M architecture: as the name indicates, it cannot be ‘masked’ by the usual ‘disable interrupts’ flags (PRIMASK, BASEPRI), similar to the Reset signal.
cortex-m-vector-table (Source: adapted from arm.com)
Dealing with the reset signal is kind of obvious, and most designs and boards have it routed to a reset button or similar. The NMI is less obvious if you don’t pay attention to it: most ARM-Cortex implementations and boards have the NMI signal routed to a pin and are ‘hiding’ it in the schematics behind a normal GPIO pin or port: if you don’t pay attention to the NMI functionality, the board might not work as intended.
As promised I’m going to share more details about the “60 Billion Lights” project. It is about a project to build a piece of electronics behind a 100×50 cm canvas to show animations or to display information like temperature, humidity, weather, time or just any arbitrary text.
An essential tool especially developing larger applications or distributed firmware is to use logging. This article presents an open source logging framework I’m using. It is small and easy to use and can log to a console, to a file on the host or even to a file on an embedded file system as FatFS.
FreeRTOS is pretty much everywhere because it is so simple and universal, and it runs from the smallest to the biggest systems. But it still might be that for the microcontroller device you have selected there is no example or SDK support for it from your vendor of choice. In that case: no problem: I show how you could easily add FreeRTOS plus many more goodies to it.
It is one thing to create something ‘cool’ or technically interesting. But it is a completely different story to convince your girlfriend, partner, wife, family (or whatever you can name it) to hang something on a wall in our house or office. Then it is not about technology: it is more about design and art. So here is my attempt to solve that challenge:
Displaying temperature with a painted canvas, stepper motors and 2400 RGB LEDs
I’m using the NXP Kinetis K22FN512 in many projects, either with the FRDM-K22F or on the tinyK22: with 120 MHz, 512 KByte FLASH and 128 KByte it has plenty of horsepower for many projects. The other positive thing is that it is supported by the NXP MCUXpresso IDE and SDK. I have now created an example which can be used as base for your own project, featuring FreeRTOS, FatFS, MinIni and a command line shell.
FreeRTOS has many cool features, and one is that it can report the CPU percentage spent in each task. The downside is that to get this kind of information some extra work is needed. In this article I show how to do this for the NXP i.MX1064.
Especially in a lab or classroom environment it is convenient to start with a template project, and then explore different ways to shape the project for different needs. As for any IDE of this world, this requires an understanding of the inner workings to get it right. So in this article I show how to copy, clone or rename properly an Eclipse ‘template’ project in the MCUXpresso IDE.
The gnuplot is a versatile and powerful tool to plot and visualize all kind of data. I wish there would be a plugin for it in Eclipse. But as this is not (yet?) the case, here is how I’m using it with gdb and Eclipse, using the MCUXpresso IDE as example.
Eclipse with its CDT managed Make system makes it easy to build projects, because it can handle a lot of the background tasks and settings between the project and the build setting. It can get a bit difficult if I want to include a library or other sub-source project for which I have to add extra compiler #define or add extra includes path settings.
Eclipse project settings for include paths
This article show the different ways I have found to make such imports (and exports) easier.