nRF52 BLE Christmas Tree

For your Festive delectation, some nRF52 BLE-controlled Christmas Tree lights:

I had some RGB light strips left over - not individually addressable;  the entire strip has the same colour.

I used an nRF52 and Nordic UART Service (NUS) to link to the phone; no fancy app - I just enter RGB numbers in the Nordic UART app.

The strips are controlled by 3-terminal FET switches: 3 per strip (R, G, and B) and there are 4 strips - so a total of 12 switches.

Each switch is driven by an instance of the Nordic SDK Low-power PWM.