#!/bin/bash
if [ ! -e /sys/class/gpio/gpio4 ]; then
echo "File exists."
echo "4" > /sys/class/gpio/export
fi
echo "out" > /sys/class/gpio/gpio4/direction
echo "0" > /sys/class/gpio/gpio4/value
sleep 2
echo "1" > /sys/class/gpio/gpio4/value