pi-fancontrol

Control a fan attached to a GPIO via NPN transistor (defaults to GPIO 14 (pin 8))

For more info see https://ograblog.wordpress.com/2019/10/09/attaching-a-cpu-fan-to-a-rpi-running-ubuntu-core/

Make sure to connect the snap interface for the correct GPIO that your fan is attached to (see https://pinout.xyz for correct mapping)

 snap connect pi-fancontrol:gpio pi:bcm-gpio-14

The snap allows a few configurations to be set

Pick a different GPIO to swithc the fan on/off (do not forget to use the above connect command to enable access to this changed GPIO)

 snap set pi-fancontrol gpio=23

Set the temperature threshold (in degrees celsius) at which the fan turns on

 snap set pi-fancontrol threshold=40

Set the interval (in seconds) at which the temperature gets scanned

 snap set pi-fancontrol interval=60

Indeed you can set all these also from a gadget.yaml file in the ```defaults:``` section.