In “Touch & Build: Auto-Update of Firmware Date and Time” I’m using commands as ‘touch’ in a pre-build script with the NXP Eclipse based MCUXpresso IDE. That ‘touch’ command is not a Windows shell command, but common on Linux: it updates the time/date of a file.
Build Step Dialog in MCUXpresso IDE
As a Windows user you might wonder what is about this ‘Linux compatible shell’?
It is very valuable to have a date and time information in the binary. That way for example using a shell I can check the version of the firmware running on a device, or it can be printed on a console or UART as needed.
If you are not aware (yet?): it looks like the COVID pandemic caused a global silicon and microcontroller shortage with lead times >50 weeks in some cases. The microcontroller I have used for the MetaClockClock build (see “New MetaClockClock V3 finished with 60 Clocks” and “MetaClockClock V4 for the Year 2021“) is affected by this too, but I had luck and still enough microcontrollers to build a few more boards.
So I still have enough for building a new variant with it (not finished yet). While everyone else is waiting for the devices to arrive, here are more details and instructions for your own build.
One of the most frustrating part developing embedded applications is if the debug connection fails somehow: with all the different factors like operating system, virtual machines, USB ports and hubs, debug probe and firmware a ‘connection failed’ is my nightmare. And this is probably the most frustrating parts for my students (and myself!)
“A young man is smoking one cigarette after each other without a pause. An elderly woman observes that and says: “Young man, you are smoking like crazy! Don’t you know that there is a warning on each cigarette package that this can kill you?” The young man finishes his cigarette, looks at the elderly person and says: “Yes, I know. But look, I’m a programmer, and it is only a warning.”
I don’t smoke, and I do pay attention to warnings :-). I always try to keep my source code free of compiler warnings. And I always pay special attention to the following on:
If you are developing Linux or desktop applications with GNU tools, you very likely are familiar with gcov: the GNU coverage tool. It collects data what parts of the code gets executed and represents that in different formats, great to check what is really used in the application code or what has been covered during multiple test runs.
Coverage Information with gcov
line never executed
GNU coverage is possible for resource constraint embedded systems too: it still needs some extra RAM and code space, but very well spent for gathering metrics and improves the firmware quality. As I wrote in “MCUXpresso IDE V11.3.0 for 2021” things are now easier to use, so here is a short tutorial how to use it.
There are many different aspects of Open Source projects: It is not only about the fact if the sources are available (‘open’). It is about the licensing terms (how permissible is it, what can I do with it), maintenance and continuous development (what has changed between releases), how and where is it delivered (Sourceforge, dedicated distribution, packaging) up to collaboration (how can I contribute or submit issues).