Hi,
It's possible to control GPIO´s even without RPi.GPIO or similar.
You just have to do it a bit differently.
When I first got my Pi and started to fiddle around with overclocking etc. I believed that I had to use a fan to cool it down. But I was obviously wrong
Anyway, after some time I found the fan noise very annoying so I decided to make script to control the fan speed depending on CPU temp I wrote this shell script to control a ULN2003 driver module and together with some resistors the GPIO's controlled the fan speed.
Code:
#!/bin/bash
#
#
# Raspberry Pi cooling fan stepper.
#
# Set temperature thresholds in /storage/scripts/CPU_Temp.txt
#
# Script created by Patrics83
#
#####################################################################
#
# Setting up GPIO:s
echo "22" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio22/direction
echo "23" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio23/direction
echo "24" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio24/direction
echo "25" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio25/direction
GPIO22="/sys/class/gpio/gpio22/value"
GPIO23="/sys/class/gpio/gpio23/value"
GPIO24="/sys/class/gpio/gpio24/value"
GPIO25="/sys/class/gpio/gpio25/value"
#####################################################################
#
# Test all fan speeds during boot and lock it at step 5 for 10 seconds.
echo "1" > $GPIO22
sleep 2
echo "0" > $GPIO22
echo "1" > $GPIO23
sleep 2
echo "1" > $GPIO22
sleep 2
echo "0" > $GPIO22
echo "0" > $GPIO23
echo "1" > $GPIO24
sleep 2
echo "0" > $GPIO24
echo "1" > $GPIO25
sleep 10
echo "0" > $GPIO25
#####################################################################
#
# Read preference file
T1=`grep "CPU_TEMP_1" /storage/scripts/CPU_Temp.txt | cut -d'=' -f2-`
T2=`grep "CPU_TEMP_2" /storage/scripts/CPU_Temp.txt | cut -d'=' -f2-`
T3=`grep "CPU_TEMP_3" /storage/scripts/CPU_Temp.txt | cut -d'=' -f2-`
T4=`grep "CPU_TEMP_4" /storage/scripts/CPU_Temp.txt | cut -d'=' -f2-`
T5=`grep "CPU_TEMP_5" /storage/scripts/CPU_Temp.txt | cut -d'=' -f2-`
#####################################################################
#
# Start the fan automation
while
CPU_TEMP1=`cat /sys/class/thermal/thermal_zone0/temp`
CPU_TEMP2=$(($CPU_TEMP1 / 1000))
do
if [ "$CPU_TEMP2" -ge "$T5" ]; then
echo "Fan step 5"
echo "0" > $GPIO22
echo "0" > $GPIO23
echo "0" > $GPIO24
echo "1" > $GPIO25
else
if [ "$CPU_TEMP2" -ge "$T4" ]; then
echo "Fan step 4"
echo "0" > $GPIO22
echo "0" > $GPIO23
echo "0" > $GPIO25
echo "1" > $GPIO24
else
if [ "$CPU_TEMP2" -ge "$T3" ]; then
echo "Fan step 3"
echo "0" > $GPIO24
echo "0" > $GPIO25
echo "1" > $GPIO22
echo "1" > $GPIO23
else
if [ "$CPU_TEMP2" -ge "$T2" ]; then
echo "Fan step 2"
echo "0" > $GPIO22
echo "0" > $GPIO24
echo "0" > $GPIO25
echo "1" > $GPIO23
else
if [ "$CPU_TEMP2" -ge "$T1" ]; then
echo "Fan step 1"
echo "0" > $GPIO23
echo "0" > $GPIO24
echo "0" > $GPIO25
echo "1" > $GPIO22
else
echo "Fan step 0"
echo "0" > $GPIO22
echo "0" > $GPIO23
echo "0" > $GPIO24
echo "0" > $GPIO25
fi
fi
fi
fi
fi
sleep 5
done
Long story, but since I'm not a pro at this I figured it was easier to show you how I have been working with the codes...
In short you can use this code to toggle a gpio on/off.
Code:
echo "22" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio22/direction
# GPIO 22 ON
echo "1" > /sys/class/gpio/gpio22/value
# GPIO 22 OFF
echo "0" > /sys/class/gpio/gpio22/value
What are you trying to do with the GPIO's?
