External power support was added in #242, however, the BlueMicro840 is missing this definition from its DT. It looks like the BlueMicro840 uses P0.12 with an active high (rather than low of the nice!nano): Source

• support --mf <file_name> in west init and add manifest.file to the config
• also fall back on west.yaml if west.yml is missing

The pinetime watch has a small motor to produce vibration. Let's imake it work !

The motor is plugged on the GPIO P0.16 of the NRF52. See image.

I guess simply driving low and high this GPIO would make it work.
We will need some kind of thread or timer if we want to make some spec