Good news: I wrote a #fennel program to blink the backlight on my #pinetime

https://github.com/telent/chablon/blob/main/hello.fnl

Next step: write some Lua SPI bindings so I can put pixels on the screen too

(Bad news: my "Hack Magic Probe" (black magic probe on a blackpill) has died, and ST-Link/OpenOCD has significantly less smooth support for RTT, so no more printf debugging)