Rock 3C with 25W POE Hat - Fan Control


Does anyone have a good suggestion for a stepwise temperature control of the fan on the 25W POE Hat when combined with Radxa Rock 3c and Armbian (Debian Bookworm)?

I understand the PWM based method discussed in this forum will not work, as pin 33 on the 3c does not have PWM capabilities.

The fan spins like a jet engine if I keep it plugged in, I am worried it will take off with the 3c.