Shell Script that blinks an LED on pcDuino

blink_led.sh

#!/bin/bash
modprobe gpio-sunxi

echo 3 > /sys/class/gpio/export
pindir=`ls -d /sys/class/gpio/gpio3*`
directionfile="${pindir}/direction"
valuefile="${pindir}/value"

echo "Direction file is ${directionfile}"
echo "Value     file is ${valuefile}"


echo 'out' > ${directionfile}


for i in `seq 1 20`
do
echo "On"
sleep 1
echo  1 > ${valuefile}
sleep 1
echo "Off"
echo  0 > ${valuefile}
done

echo 3 > /sys/class/gpio/unexport
modprobe -r gpio-sunxi