Milk-V Pioneer fan control

milkv-pioneer-fan-control.md

DRAFT status

This is very much a draft still as I go along. Everything in here is subhect to change heavily, could be wrong and your mileage may vary greatly.

Everything here assumes native build on Arch POWER riscv64.

This is probably broken in some way but works for me.

#!/bin/bash

MAXTEMP=70000 # 70C
MEDTEMP=65000 # 65C

while [ true ]; do
  TEMP1=$(cat /sys/class/hwmon/hwmon0/temp1_input)
  TEMP2=$(cat /sys/class/hwmon/hwmon0/temp2_input)

  echo "${TEMP1} ${TEMP2}"

  if [ ${TEMP1} -lt ${MAXTEMP} -o ${TEMP2} -lt ${MAXTEMP} ]; then
    if [ ${TEMP1} -lt ${MEDTEMP} -o ${TEMP2} -lt ${MEDTEMP} ]; then
      echo ":: limit to 20%"
      echo 180 > /sys/class/hwmon/hwmon2/pwm1
    else
      echo ":: limit to 40%"
      echo 120 > /sys/class/hwmon/hwmon2/pwm1
    fi
  fi
  sleep 1
done

This was mostly correct for mine; the two references to hwmon2 were incorrect, but easily modified to hwmon1 and then it worked as expected

After a system update I now have hwmon[0-3] and 2 is the correct one, so I guess it depends if you're running the stock image or if you've upgraded. Either way, thanks.