ReadyNAS RN 104 Automatic FAN-Control

MAXFAN=100   # Maximum operable speed
MINFAN=0     # Minimum operable speed
MINPWM=75    # PWM Limit
MAXPWM=255   # PWM Limit
MINTEMP=42   # Min temp -> Fan slowest
MAXTEMP=58   # Max temp -> Fan fastest
NEWSPEED=50  # Initial fan speed (%)

#!/bin/bash

## Variables ##
FANPWMPATH=/sys/devices/platform/mv64xxx_i2c.0/i2c-0/0-003e/pwm1
FANSPEEDPATH=/sys/devices/platform/mv64xxx_i2c.0/i2c-0/0-003e/fan1_input
CORETEMPPATH=/sys/devices/platform/axp-temp.0/temp1_input
MAXFAN=100   # Maximum operable speed
MINFAN=0     # Minimum operable speed
MINPWM=75    # PWM Limit
MAXPWM=255   # PWM Limit
MINTEMP=42   # Min temp -> Fan slowest
MAXTEMP=58   # Max temp -> Fan fastest
NEWSPEED=50  # Initial fan speed (%)

## Functions ##
function getReadings {
    FANPWM=$(cat $FANPWMPATH)
    FANSPEED=$(cat $FANSPEEDPATH)
    CORETEMP=$(cat $CORETEMPPATH)
}

function setFanSpeed {
    if [ $NEWSPEED -lt $MINFAN ]; then
        NEWSPEED=$MINFAN
    fi
    if [ $NEWSPEED -gt $MAXFAN ]; then
        NEWSPEED=$MAXFAN
    fi
    NEWPWM=$(expr $MAXPWM - $MINPWM)
    NEWPWM=$(expr $NEWPWM \* $NEWSPEED)
    NEWPWM=$(expr $NEWPWM / 100)
    NEWPWM=$(expr $NEWPWM + $MINPWM)

    echo $NEWPWM > /sys/devices/platform/mv64xxx_i2c.0/i2c-0/0-003e/pwm1
   }

function calcFanPercent {
    TEMPRAN=$(expr $MAXTEMP - $MINTEMP)
    TEMPREL=$(expr $CORETEMP - $MINTEMP)
    TEMPREL=$(expr $TEMPREL \* 100)
    TEMPPER=$(expr $TEMPREL / $TEMPRAN)
    NEWSPEED=$TEMPPER
}

###################################################################
echo "Automatically controlling fan speed..."
while true
do
    getReadings
    echo "Temp: $CORETEMP C    FAN: $NEWSPEED% [$FANSPEED RPM] [$FANPWM]"

    calcFanPercent
    setFanSpeed

    sleep 10
done
###################################################################

#!/bin/sh
### BEGIN INIT INFO
# Provides: FanOveride
# Required-Start: $local_fs $network $named $time $syslog
# Required-Stop: $local_fs $network $named $time $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Description: FanOveride overides the default ReadyNAS fan control
### END INIT INFO

SCRIPT=~/fanoveride
RUNAS=root

PIDFILE=/var/run/fanoveride.pid
LOGFILE=/var/log/fanoveride.log

start() {
if [ -f /var/run/$PIDNAME ] && kill -0 $(cat /var/run/$PIDNAME); then
echo 'Service already running' >&2
return 1
fi
echo 'Starting service.' >&2
local CMD="$SCRIPT &> \"$LOGFILE\" & echo \$!"
su -c "$CMD" $RUNAS > "$PIDFILE"
echo 'Service started' >&2
}

stop() {
if [ ! -f "$PIDFILE" ] || ! kill -0 $(cat "$PIDFILE"); then
echo 'Service not running' >&2
return 1
fi
echo 'Stopping service.' >&2
kill -15 $(cat "$PIDFILE") && rm -f "$PIDFILE"
echo 'Service stopped' >&2
}

uninstall() {
echo -n "Are you really sure you want to uninstall this service? That cannot be undone. [yes|No] "
local SURE
read SURE
if [ "$SURE" = "yes" ]; then
stop
rm -f "$PIDFILE"
echo "Notice: log file is not be removed: '$LOGFILE'" >&2
update-rc.d -f <NAME> remove
rm -fv "$0"
fi
}

case "$1" in
start)
start
;;
stop)
stop
;;
uninstall)
uninstall
;;
retart)
stop
start
;;
*)
echo "Usage: $0 {start|stop|restart|uninstall}"
esac