The MCU-Link is a small and inexpensive $10 CMSIS-DAP debug probe from NXP. It can work with OpenOCD, but has better target support using the NXP LinkServer which implements a gdb server. This makes it an ideal combination for scripting or automated testing.
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 readingI’m working recently on a new lecture module using the Raspberry Pi Pico (RP2040) board, which highlights several aspects of modern software engineering, including DevOps and CI/CD. An important part of any CI/CD pipeline is testing. For a host application, one could pass arguments to the application, e.g. ‘myapp --test=module1‘, or let it read such information from a configuration file which describes the tests. Or write GNU gcov data to a file to collect coverage information.
Unfortunately, a normal embedded application has no argv[], and many system have no file system. A solution to this problem would be using semihosting with file I/O. Unfortunately for the Raspberry Pi Pico SDK 1.5.1 for the RP2040, there is no semihosting file I/O implemented :-(.
I have now implemented and added file I/O to the SDK, making it possible for the RP2040 to access and use files on the host, among other things. This greatly extends the capabilities of the device, and is very useful for testing, including gathering test coverage information.
For systematic debugging, an engineer needs a debug probe. For the Raspberry Pi Pico (RP2040) device there are plenty of debug options with VS Code.
In this article I show different options, from professional tools to DIY solutions and the settings in VS Code I’m using.
Continue readingWith semihosting I can use standard I/O function like printf() and I can read and write data on the host through the debug connection. If used with care, this is a great feature especially for unit testing.
I have lots of hardware and debug probes on my desk, and I discussed using nicknames for debug probes to better identify them.
So far so good. At that time of the previous article, it was possible to assign nicknames to J-Link debug probes, but not to use the nickname instead of the USB serial number. Well, SEGGER was fast again, and responded with a new J-Link software pack version 7.92d which implements that features: I can now use the nickname to connect to a debug probe :-).
Continue readingSometimes I have a wish. Not every time it gets fulfilled. But this time I’m lucky and happy developer. A few days ago I wrote about the LPC4322-based SEGGER OB (on-board) J-Link firmware. It works great, but the board requires another USB cable to power the target board.
Rolf Segger contacted me, and a few days later I had a J-Link firmware with a ‘power-on’ feature:
That way, only one USB cable is needed. All what you need to do is to update the firmware.
Continue readingGoing with the factory default can be fine. But an upgrade could give a performance boost plus added functionality. Many of the NXP i.MX RT evaluation boards have an LPC4322 based debug circuit on it. One example for this is the i.MX RT1010 board.
On such boards, one of the first steps I do is: upgrading the firmware and change it to a better option: improved speed, SWO support plus avoiding issues with the USB MSD device.
Continue readingWe have a project imported, have built it, time to debug it on the hardware.
With “Adding RGBW Wings and Enclosure to a Debug Probe” I have a really shiny enclosure for the MCU-Link Pro Enclosure.
But I did not had enough time to replicate this for a full set of classroom hardware. The original card boxes from NXP showed already after one semester severe wear, so I have to setup something more robust: a box to store all the cables, and an enclosure to protect the PCB, for 40 units.
3D printing would take to much time, so I ended up with buying storage boxes and creating an laser-cut acrylic (PMMA) enclosure for the debug probe itself:
