#!/bin/sh set -e case "$1" in start) echo "Enabling audio..." if ! [ -d /sys/class/gpio/gpio144 ] ; then echo 144 > /sys/class/gpio/export echo out > /sys/class/gpio/gpio144/direction fi echo 1 > /sys/class/gpio/gpio144/value ;; stop) ;; *) echo "Usage: $0 {start|stop}" >&2 exit 1 ;; esac