FreeRTOS seems to get more and more popular, and I think as well because more and more debugger and Eclipse IDE vendors add dedicated debugging support for it.
FreeRTOS Threads in Eclipse
By default, the GNU Linker expects a very special naming scheme for the libraries: the library name has to be surrounded by “lib” and the “.a” extension:
lib<NAME>.a
But what if the library I want to use does not conform to that naming standard?
Non-conforming Library Naming
The benefit of an IDE like Eclipse is: it makes working with projects very easy, as generates make files and it takes and automatically manages the make file(s). But sometimes this might not be what I want because I need greater flexibility and control, or I want to use the same make files for my continues integration and automated testing system. In that case a hand crafted make file is the way to go.
One thing does not exclude the other: This article explains how to use make files with Eclipse with similar comfort as the managed build system in Eclipse, but with the unlimited power of make files:
Makefile Project with Eclipse
A bootloader on a microcontroller is a very useful thing. It allows me to update the firmware in the field if necessary. There are many ways to use and make a bootloader (see “Serial Bootloader for the Freedom Board with Processor Expert“). But such a bootloader needs some space in FLASH, plus it needs to be programmed first on a blank device, so a JTAG programmer is needed. That’s why vendors have started including a ROM bootloader into their devices: the microcontroller comes out of the factory with a bootloader in FLASH. So instead writing my bootloader, I can use the one in the ROM.
FRDM-KL03Z with ROM Bootloader
And as with everything, there are pros and cons of that approach.
For a research project, we are going to send a satellite with an embedded ARM Cortex microcontroller into space early next year. Naturally, it has to work the first time. As part of all the ESA paperwork, we have to prove that we tested the hardware and software thoroughly. One piece of the that is to collect and give test coverage evidence. And there is no need for expensive tools: Free-of-charge Eclipse and GNU tools can do the job for a space mission 🙂
Eclipse with Coverage Views
In “Cycle Counting on ARM Cortex-M with DWT” I have used the ARM DWT register to count the executed cycles. With the MCUXpresso IDE comes with a very useful feature: it can capture the ARM SWO (Single Wire Output) trace data. One special kind of trace data is the ‘cycle counter’ information which is sent through SWO.
SWO Counters
I believe in ‘life-long-learning’. With this I continue to learn and discover new things every day. I’m writing tutorials to give something back to the community from which I have learned so much.
On top of this, I receive emails on a nearly daily basis, asking for help. Many articles have the origin in such requests or questions. I prefer questions or comments in a public forum, because that way I feel all others can benefit from it. Last week Alessandro contacted me with this:
“Hi Erich,
I hope this find you well! I’m starting to using ARM processors, but I find them quite complicated on the configuration side. I started in the past with PIC micro (PIC16) with asm, and I found them quite straightforward to be configured (clock, IO, peripherals, …). Then I moved myself on C language, and on PIC18 without any big issues.
Now I would really like join the ARM community, I see that these processors are what I’ve always looking for, on energy, calc power, peripherals, and FINALLY on IDE (editor, toolchain and utilities)… AMAZING!!!”
The topic is about how to start learning developing for ARM. Alessandro agreed to make this public, so I thought this might be a good topic for an article?
Firmware
Looking for a small, inexpensive ($25-30) ARM development board (say 120-180 MHz ARM Cortex-M4 with FPU, 512kB-1MB of FLASH and 256 KByte of RAM? Then have a look at the Teensy 3.5 and Teensy 3.6 by PJRC/Paul Stoffregen:
Teensy 3.5 with NXP K64F ARM Cortex-M4F
The only problem? it is not possible to debug it :-(. At least not in the traditional sense. This article is about how to change the board to use it with any normal SWD debugging tool e.g. Eclipse and the Segger J-Link :-).
Space is a hostile environment. Sending hardware to space means putting it under irradiation tests: exposing the object to radiation and see what happens :-). For this, under the lead of the ETHZ (Mathematical and Physical Geodesy), we had the opportunity to put the CubETH payload board under a proton beam. The test facility is at the Paul Scherrer Institute (PSI) in Villigen, Switzerland:
Control Room at PSI
An interesting trend in the industry are SOM (System on Module): a high performance processor typically running Linux, Windows or Android with all the memory and necessary power logic gets put on a small module. The key benefit is that I don’t need to worry about the complex ball grid routing and the DDR memory connections/lines: all these problems are solved on a small module which then I can use in my design. It seems that NXP i.MX application processors are getting popular in this domain, and after looking at the Toradex Colibri modules, I have an i.MX6 module on my desk from e-con Systems:
eSOMiMX6-micro Top Side
MCU on Eclipse 