Bitearable does exactly what it says on the tin. We use it for the microbit V1 and V2, but you can use it as well for other systems as battery supply, see pictures. We have a project called MyCo, first the name was TPS. How to program WITHOUT a PC if needed. As well on microbit V1 and V2 There is a facebook group https://www.facebook.com/groups/269499491046124/about And as you can see, Strap and Board can be used to mount other boards as well. Regarding microbit: grab the V1 or V2 HEX file from Neil's github, throw it into the microbit folder, and start programming. More you can find on our facebook page. Want to understand it a bit more? Then you can download the TPS Emulator onto your PC , program and test, then get it onto your Bitwaerable. Great piece of hardware. See some pictures of how it is used. It all started with Burkhard Kainka's TPS https://www.elektronik-labor.de/Lernpakete/TPS/TPS0.html unfortunately in German, but some microbit info in English here https://www.elektronik-labor.de/Lernpakete/TPS/TPS45.html and many links to others. And I have to get an FPGA board, as there is a version of MyCo running on FPGA. With a little Interface Board as for the Holtek version shown.