#!/bin/sh

for x in 1 2 4 6; do
    echo 0 > /dev/gpio$x
done

usleep 500000

while /bin/true; do
    for x in 1 2 4 6; do
	echo 1 > /dev/gpio$x
	usleep 500000
	echo 0 > /dev/gpio$x
    done
done
