How to control the PWM Fan on ODROID-H2

First of all, you should enter the BIOS to enable the ODROID-H2's Fan.

1. Power off your ODROID-H2.
2. Press the Power button on your ODROID-H2, then Press “DEL” key while booting.
3. You can see the pic as follow.

You can adjust the board's temperature to turn on the system FAN. And you can also adjust the Fan's speed with RPM.
The maximum RPM that you can set is 4000 in BIOS but the maximum RPM of the Hardkernel official PWM Fan is 2000.
https://www.hardkernel.com/shop/92x92x25mm-dc-cooling-fan-w-pwm-speed-sensor-tacho/

Note that the temperature values are from the PCB sensors instead of the CPU inside.
Generally, the board temperature is 5~25°C lower than CPU internal.

Move to the Save & Exit tab. And then, select the “Save Changes and Exit” menu.