라즈베리파이 4 gpio를 이용한 팬 컨트롤 (bash script)
라즈베리파이 4에서 gpio를 이용한 fan control을 bash script로 구현했다.
라즈베리파이의 BCM 21번 핀에 FAN 제어 핀을 연결했다.
sudo crontab에 등록해서 30초에 한 번씩 실행되도록 했고 정상적으로 잘 동작한다.
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#!/bin/bash
# CPU Temperature Monitoring
# Add sudo cron job for use.
usage()
{
cat <<EOF
Usage: $(basename "${BASH_SOURCE[0]}") [-h|--help] <pin> <temperature>
Default: pin=21, tempertaure=45
EOF
exit
}
parse_params()
{
while :; do
case "${1-}" in
-h | --help) usage ;;
*) break ;;
esac
shift
done
}
parse_params "$@"
# Default
FAN=21 # BCM pin
THRSH_TEMP=45 # Temperature of CPU to control fan (Fan ON if temp is higher)
if [ $# -eq 2 ]; then
FAN=$(($1))
THRSH_TEMP=$(($2))
fi
GPIO="gpio${FAN}" # Other way. not use.
echo "Fan Pin = ${FAN} pin BCM"
echo "Threshold Temperature = ${THRSH_TEMP} celsius"
ON=1
OFF=0
# Check if WiringPi is installed
CMD_GPIO=`which gpio`
if [ -z ${CMD_GPIO} ]; then
echo "Not installed gpio. Please install WiringPi"
echo "https://github.com/wiringpi/wiringpi"
exit
fi
# Init GPIO
$CMD_GPIO -g mode $FAN output
# Get CPU Temperature
get_cpu_temp()
{
RAW_TEMP=$((`cat /sys/class/thermal/thermal_zone0/temp`))
echo $(($RAW_TEMP/1000)) # return integer value
}
# Fan ON
fan_on()
{
# FAN ON
$CMD_GPIO -g write $FAN $ON
# Other way. But not use.
# Because this way you can see these message > echo: write error: Deice or resource busy
#`echo $FAN > /sys/class/gpio/export`
#`echo "out" > /sys/class/gpio/${GPIO}/direction`
#`echo "1" > /sys/class/gpio/${GPIO}/value`
}
# Fan OFF
fan_off()
{
# FAN OFF
$CMD_GPIO -g write $FAN $OFF
# Other way. But not use.
# Because this way you can see these message > echo: write error: Deice or resource busy
#`echo "0" > /sys/class/gpio/${GPIO}/value`
#`echo $FAN > /sys/class/gpio/unexport`
}
# Fan control
fan_control()
{
CPU_TEMP=$(get_cpu_temp)
if [ $CPU_TEMP -gt $THRSH_TEMP ]; then
fan_on
echo " Current CPU Temperature = ${CPU_TEMP} celsius. Fan On."
else
fan_off
echo " Current CPU Temperature = ${CPU_TEMP} celsius. Fan Off."
fi
}
# sudo check
if [ $(id -u) -ne 0 ]; then exec sudo bash "$0" "$@"; exit; fi
fan_control
참고 자료
- 라즈베리파이4b에 최신 버전 wiringpi 설치하는 방법 - https://hoho325.tistory.com/212
- [Raspberry Pi GPIO 활용하기 (쉘 스크립트)] - https://201301651.tistory.com/5
- [[라즈베리파이] 발열 테스트 및 CPU 온도 확인 방법] - https://frankler.tistory.com/22