ERICSL reacted to
mar0ni in PWM Fan on Nanopi M4 ??
Slightly improved and simplified script (still room for improvement, I guess).
#!/bin/bash
if [ ! -d /sys/class/pwm/pwmchip1/pwm0 ]; then
echo 0 > /sys/class/pwm/pwmchip1/export
fi
sleep 1
while [ ! -d /sys/class/pwm/pwmchip1/pwm0 ];
do
sleep 1
done
ISENABLE=`cat /sys/class/pwm/pwmchip1/pwm0/enable`
if [ $ISENABLE -eq 1 ]; then
echo 0 > /sys/class/pwm/pwmchip1/pwm0/enable
fi
echo 50000 > /sys/class/pwm/pwmchip1/pwm0/period
echo 1 > /sys/class/pwm/pwmchip1/pwm0/enable
# max speed run 5s
echo 0 > /sys/class/pwm/pwmchip1/pwm0/duty_cycle
sleep 5
echo 49994 > /sys/class/pwm/pwmchip1/pwm0/duty_cycle
declare -a CpuTemps=(75000 63000 58000 52000 48000 0)
declare -a PwmDutyCycles=(25000 37000 48300 49250 49300 49994)
while true
do
temp=$(cat /sys/class/thermal/thermal_zone0/temp)
for i in 0 1 2 3 4 5; do
if [ $temp -gt ${CpuTemps[$i]} ]; then
DUTY=${PwmDutyCycles[$i]}
echo $DUTY > "/sys/class/pwm/pwmchip1/pwm0/duty_cycle";
#echo "temp: $temp, target: ${CpuTemps[$i]}, duty: $DUTY"
break
fi
done
sleep 2s;
done