BBC micro:bit support

[whaleygeek]

I'm pondering adding support for BBC micro:bit - basically adding a HRFM69 module as a back-pack to a micro:bit.

The microbit-DAL has a SPI class.

http://lancaster-university.github.io/microbit-docs/extras/spi/

Could be a nice project to get school children engaged with real energy measurement and power control of science experiments in the classroom, perhaps.

[whaleygeek]

MicroPython has an SPI abstraction that knits up to the DAL SPI driver, this might be the easiest way to get this to work, in a way that is accessible to most users.

https://microbit-micropython.readthedocs.io/en/latest/spi.html

[whaleygeek]

I've had a few requests for this recently (note @jaustin I might consider doing this!)