Setting up yotta and C with the BBC micro:bit by modifying the examples directory

I wrote this before the micro:bit v2 came out. I don’t know if these instructions are valid for the micro:bit v2.

I set up to program the BBC micro:bit (which I’ll call the microbit from now on) in C/C++ under Linux. I’ve been using micropython to program the boards up to now, but want to leverage the increased performance that using C can give and some of the C libraries that are available for e.g. encryption.

There is good documentation on the Lancaster University microbit github page:

https://lancaster-university.github.io/microbit-docs/

I installed the offline tools as I spend a lot of time working at sea where you can’t always rely on having an internet connection. I got a demo compiled and loaded by following the instructionso n the Lancaster University github site. Now it was time to write my own code. I had a little trouble getting this going, so here’s what I had to do to get my first program compiled and loaded. I did this by modifying the structure of the examples directory that was created by following the github instructions.

I downloaded the github repository linked above into

~/git/microbit-samples

Initially I made a new directory under:

~/git/microbit-samples/source/my_code

Whenever I ran ‘yt build’, I got a weird error referring to one of the bluetooth example programs. Plus yt build took longer than I thought it ought to. So…..

Move

~/git/microbit-samples/source/examples

out of:

~/git/microbit-samples/source/

Put these folders one level above this folder. Only put the main.cpp file into

~/git/microbit-samples/source/

Then run:

yt clean

and

yt build

I copied the file:

~/git/microbit-samples/build//bbc-microbit-classic-gcc/source/microbit-c-combined.hex

to the microbit. After waiting for the flashing LEDs to stop, it worked!

The microbit unmounts itself each time that you load a new hex file. So using the bash script that I detailed in an earlier blog to quickly mount the microbit is a time saver.

This is a quick way of getting started by building on top of the examples directory that most folk will start with.

disclaimer: I loiter in the same department as the authors of the C/C++ BBC micro:bit repository.