The holiday break at the end of the year is always a good time to finish projects started during the year. This one is about my ‘MetaClockClock’ Version 3.
The NXP MCU-Link is a powerful $10 debug probe for ARM Cortex-M devices and works with the NXP LinkServer for debugging. The LinkServer does not an implement a gdb server, so it limits its usage e.g. for scripting or command line debugging. But as MCU-Link is also a CMSIS-DAP compatible debug probe, I can use it with OpenOCD which is open source and implements a GDB server. This article shows how I can use it with the MCU-Link.
Reentrancy is an attribute of a piece of code and basically means it can re-entered by another execution flow, for example by an interrupt or by another task or thread. This is an important concept and still a lot of code ‘in the wild’ does violate reentrancy. As a result the application crashes immediately in the best case. Worse it crashes randomly or even worse it behaves incorrectly 😦 .
Reentrancy is always a concern if using standard library functions, including printf() or malloc(). FreeRTOS offers a reentrant wrapper to the standard malloc() and free() (Memory Scheme 3)
If you are a regular reader of my articles, you probably know that I’m using FreeRTOS in most of my applications, for obvious reasons. But clearly this is not the only RTOS out there. After Microsoft had acquired Express Logic back in April 2019 things kept quite for a while. To me the crown jewel of Express Logic is the ThreadX RTOS. But recently Microsoft is pushing more and more the ‘Azure Sphere’ and trying to monetize the ‘IoT’ (I apologize for mentioning that overused acronym) application space and providing it now free for devices from selected partners which includes NXP now.
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:
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:
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.
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.