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I made Bash script what running fan for cooling. PIN20 is PWM out and this script work perfect. I run this script over therminal arroun 15 hours.

Afer all tests i register script for autoload after reboot like this:

$ sudo cp rpipwm.sh /etc/init.d/rpipwm.sh
$ sudo chmod +x /etc/init.d/rpipwm.sh
$ sudo update-rc.d /etc/init.d/rpipwm.sh defaults

After last line I get this error: update-rc.d: error: initscript does not exist: /etc/init.d//etc/init.d/rpipwm.sh

After that error I update with this:

$ sudo update-rc.d rpipwm.sh defaults

And reboot.

After reboot my script start to work and all is fine arround 20min. After that time my script stop to work. If I run this manualy on terminal script can work hours and hours with no errors.

What's mistake?

Here is my script.

#!/bin/bash
### BEGIN INIT INFO
# Provides:          rpipwm
# Required-Start:    $local_fs 
# Required-Stop:     $local_fs
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: rpipwm
### END INIT INFO

FLAG="/var/log/rpipwm.log"
if [ ! -f $FLAG ] ;
then


    a="echo 20 > /sys/class/gpio/unexport;"
    a=$a"echo 20 > /sys/class/gpio/export;"
    a=$a"echo out > /sys/class/gpio/gpio20/direction" || true
    eval $a
    #start loop script
    i="0"
    temp="0"

    while true;
    do
        i=$(($i+1))
        #Read temp
        if [[ $(bc <<< "$i > 10") == 1 ]] ;
        then
            cpuTemp0=$(cat /sys/class/thermal/thermal_zone0/temp)
            cpuTemp1=$(($cpuTemp0/1000))
        ##  cpuTemp2=$(($cpuTemp0/100))
            temp=$cpuTemp1
            i="0"
        fi
        a=""
        #If temperature is equal or lower than 39.99, the fan will stop spinning
        if [[ $(bc <<< "$temp < 39") == 1 ]] ;
        then
            a=$a"echo 0 > /sys/class/gpio/gpio20/value"
        fi
        #If temperature is between 40 and 42.99, the fan will start with 1 second burst and 1 second sleep
        if [[ $(bc <<< "$temp >= 40 && $temp <= 44") == 1 ]] ;
        then
            a=$a"echo 1 > /sys/class/gpio/gpio20/value; sleep 0.5; echo 0 > /sys/class/gpio/gpio20/value; sleep 0.1 "
        fi
        #If temperature is between 43 and 47.99, the fan will start with 1 second burst and 0.5 second sleep
        if [[ $(bc <<< "$temp >= 45 && $temp <= 49") == 1 ]] ;
        then
            a=$a"echo 1 > /sys/class/gpio/gpio20/value; sleep 1; echo 0 > /sys/class/gpio/gpio20/value; sleep 0.5" 
        fi
        #If temperature is equal or higher than 48, the fan will start spinning constantly
        if [[ $(bc <<< "$temp > 50") == 1 ]] ;
        then
            a=$a"echo 1 > /sys/class/gpio/gpio20/value" 
        fi

        eval $a
        sleep 0.1
    done

touch $FLAG



fi

UPDATE

I reorder script, put log in script and now have all to work properly and with no unexpected stop or break.

#!/bin/bash
### BEGIN INIT INFO
# Provides:          rpipwm
# Required-Start:    $local_fs 
# Required-Stop:     $local_fs
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: rpipwm
### END INIT INFO
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/home/wc3/palert
FLAG="/var/log/rpipwm.log"
(
    if [ ! -f $FLAG ] ;
    then

        a="echo 20 > /sys/class/gpio/unexport;"
        a=$a"echo 20 > /sys/class/gpio/export;"
        a=$a"echo out > /sys/class/gpio/gpio20/direction" || true
        eval $a
        #start loop script
        i="0"
        temp="100"

        while true;
        do
            i=$(($i+1))
            #Read temp
            if [[ $(bc <<< "$i > 5") == 1 ]] ;
            then
                cpuTemp0=$(cat /sys/class/thermal/thermal_zone0/temp)
                cpuTemp1=$(($cpuTemp0/1000))
            ##  cpuTemp2=$(($cpuTemp0/100))
                temp=$cpuTemp1
                i="0"
            fi
            a=""
            #If temperature is equal or lower than 39.99, the fan will stop spinning
            if [[ $(bc <<< "$temp <= 39") == 1 ]] ;
            then
                a=$a"echo 0 > /sys/class/gpio/gpio20/value"
            fi
            #If temperature is between 40 and 42.99, the fan will start with 1 second burst and 1 second sleep
            if [[ $(bc <<< "$temp >= 40 && $temp <= 44") == 1 ]] ;
            then
                a=$a"echo 1 > /sys/class/gpio/gpio20/value; sleep 0.5; echo 0 > /sys/class/gpio/gpio20/value; sleep 0.1 "
            fi
            #If temperature is between 43 and 47.99, the fan will start with 1 second burst and 0.5 second sleep
            if [[ $(bc <<< "$temp >= 45 && $temp <= 47") == 1 ]] ;
            then
                a=$a"echo 1 > /sys/class/gpio/gpio20/value; sleep 1; echo 0 > /sys/class/gpio/gpio20/value; sleep 0.5" 
            fi
            #If temperature is equal or higher than 48, the fan will start spinning constantly
            if [[ $(bc <<< "$temp >= 48") == 1 ]] ;
            then
                a=$a"echo 1 > /sys/class/gpio/gpio20/value" 
            fi

            eval $a
            sleep 0.1
        done

    touch $FLAG
fi



) &> /home/pi/rpipwm.txt
Community
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Ivijan Stefan Stipić
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2 Answers2

1

This isn't an answer to the original question (as I understand, the problem disappeared on its own anyway), but rather a recommendation on your scripting.

I believe the big part of your problem is the eval statement. I don't see why you need it, and it certainly makes your code harder to debug. Also comparison operations could be made simpler using -gt and -lt operators.

Something like

        if [ $temp -lt 39 ] # temperature below 39
        then
            echo 0 > /sys/class/gpio/gpio20/value
        elif [ $temp -lt 44 ] # temperature above 39 but below 44
        then
            echo 1 > /sys/class/gpio/gpio20/value
            sleep 0.5
            echo 0 > /sys/class/gpio/gpio20/value
            sleep 0.1
        elif ... # next interval
            ... etc ...
        fi

With this code, you know for sure that (1) only one alternative can be executed at a time, and (2) the exact commands for each case. With eval $a, you can't be sure of anything unless you analyse all possible combinations of commands which modify $a.

Dmitry Grigoryev
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0

Enable auto start at boot:

sudo cp rpipwm.sh /etc/init.d/rpipwm.sh sudo chmod +x /etc/init.d/rpipwm.sh sudo update-rc.d /etc/init.d/rpipwm.sh defaults not work

john
  • 1