active cooling script recalbox

#!/usr/bin/env bash

# ~ RaspBerry PI ~
# fan control script
# -----------------------------------------
# Author:      Bagheera
# Created:     28.12.2013
# Last change: 31.12.2013
# Version      1.2
# -----------------------------------------
# 1.2: 31.12.2013
#      - traps for common signals added
#      - commentary
#      - logfile beautification
#
# 1.1: 30.12.2013
#      - logfile changed
#      - logturn added
#      - verbose by global setting
#
# 1.0: 28.12.2013
#      - control_fan.sh created
# -----------------------------------------
#1.3: Author: Snydeaps
#   Aenderung des GPIO von 14 auf 21
#   Aenderung Logfile Ordner auf luefterscript


test -n "$DEBUG" && set -x

cmd="$(basename "$0")"
lockfile="/var/run/$cmd"

exec 9<>"$lockfile"

flock -n 9 || {
  echo "ERROR: already running $(cat <&9) - exiting." >&2
  exit 1
}

echo $$ >&9

echo "running as $$"
sleep 5
echo "finished $$"

VERBOSE=1;             # show info on console (0=no; 1=yes)

MAX_THRESH=60;         # start above xx degrees
MIN_THRESH=55;         # stop below xx degrees

SLEEPER=20;            # scan every xx seconds
LOGTURN=6;             # log temp every LOGTURN * SLEEPER seconds

# logfile destination
LOGFILE="/recalbox/scripts/activecooling/control_fan.log";


# prepare signal trap function
function finish  {
    echo $(date '+%F %T %Z') "##     0:CONTROL:       Script about to stop" >> $LOGFILE
    echo $(date '+%F %T %Z') "##     2:GPIO_INIT:     Stopping fan" >> $LOGFILE
    echo "0" > /sys/class/gpio/gpio21/value
    echo $(date '+%F %T %Z') "##     2:GPIO_INIT:     Unexport of GPIO port 21" >> $LOGFILE
    echo "21" > /sys/class/gpio/unexport
    echo $(date '+%F %T %Z') "##     0:CONTROL:       Going down... bye bye" >> $LOGFILE
    exit;
}

# trap exit
trap finish EXIT

# initialize GPIO port 21
if [ ! -e "/sys/class/gpio/gpio21" ]; then
    echo $(date '+%F %T %Z') "##     ==================================================================" >> $LOGFILE
    echo $(date '+%F %T %Z') "##     0:CONTROL:       Starting up..." >> $LOGFILE
    echo $(date '+%F %T %Z') "##     1:CONFIG:        Maximum threshold $MAX_THRESH C" >> $LOGFILE
    echo $(date '+%F %T %Z') "##     1:CONFIG:        Minimum threshold $MIN_THRESH C" >> $LOGFILE
    echo $(date '+%F %T %Z') "##     1:CONFIG:        Scan interval $SLEEPER sec" >> $LOGFILE
    echo $(date '+%F %T %Z') "##     1:CONFIG:        Log temperature interval $(($SLEEPER*$LOGTURN)) sec" >> $LOGFILE
    echo $(date '+%F %T %Z') "##     2:GPIO_INIT:     Export of GPIO port 21" >> $LOGFILE
    echo "21" > /sys/class/gpio/export
    echo $(date '+%F %T %Z') "##     2:GPIO_INIT:     Direction: out" >> $LOGFILE
    echo "out" > /sys/class/gpio/gpio21/direction
    echo $(date '+%F %T %Z') "##     2:GPIO_INIT:     Port 21: init value 0" >> $LOGFILE
    echo "0" > /sys/class/gpio/gpio21/value
fi

i=0;
while [ true ]; do

    # get current recalculated temperature and fan status
    cpuTemp=$(cat /sys/class/thermal/thermal_zone0/temp)
    cpuTemp=$(($cpuTemp/1000))
    fanState=$(cat /sys/class/gpio/gpio21/value)

    # echo current temperature to logfile if logturn met
    i=$(($i+1))
    if [ $i -eq $LOGTURN ]; then
        echo $(date '+%F %T %Z') "##     0:CONTROL:       Current temperature: $cpuTemp C" >> $LOGFILE
        i=0;
    fi

    # do some info stuff
    # [ $VERBOSE -eq 1 ] && echo -e "CPU: \033[36m$cpuTemp\033[0mC  |  FAN: $fanState  |  THRESHOLD: $MIN_THRESH-$MAX_THRESH"

    # too hot and fan not running? start!
    if [ $cpuTemp -gt $MAX_THRESH ] && [ $fanState -eq 0 ]; then
        echo "1" > /sys/class/gpio/gpio21/value
        [ $VERBOSE -eq 1 ] && echo -e "====> [ \033[32mON\033[0m ]"
        echo $(date '+%F %T %Z') "##     0:CONTROL:       Starting fan ($cpuTemp C)" >> $LOGFILE
    fi

    # everything cool and fan running? stop!
    if [ $cpuTemp -lt $MIN_THRESH ] && [ $fanState -eq 1 ]; then
        echo "0" > /sys/class/gpio/gpio21/value
        [ $VERBOSE -eq 1 ] && echo -e "====> [ \033[31mOFF\033[0m ]"
        echo $(date '+%F %T %Z') "##     0:CONTROL:       Stopping fan ($cpuTemp C)" >> $LOGFILE
    fi

    sleep $SLEEPER

done