#!/bin/sh # Uncomment the following line to get debug info #set -x SELF="$(basename ${0})" SYSTEM_GPIO="/sys/class/gpio" # Power Audio Amplifier enable GPIO (('F' - 'A') * 32 + 6 = 166) GPIO_PF6=166 usage() { >2& echo "Usage: ${SELF} [1|on|ON|On for ON, 0|off|OFF|Off for OFF]" exit 1 } # Check number of arguments if [ ${#} -ne 1 ]; then usage fi case "${1}" in 1|on|ON|On) # Turn ON only if volume is not null if [ "$(volume get)" -ne "0" ]; then echo "Turning audio amplifier ON" else exit 0 fi new_state=1 ;; 0|off|OFF|Off) echo "Turning audio amplifier OFF" new_state=0 ;; *) usage ;; esac # Export the GPIO if necessary if [ ! -d "${SYSTEM_GPIO}/gpio${GPIO_PF6}" ]; then echo ${GPIO_PF6} > "${SYSTEM_GPIO}/export" fi # Set the power audio amplifier GPIO as output echo "out" > "${SYSTEM_GPIO}/gpio${GPIO_PF6}/direction" # Read the current power audio amplifier state current_state=$(cat "${SYSTEM_GPIO}/gpio${GPIO_PF6}/value") # Enable/disable the power audio amplifier if necessary if [ ${current_state} -ne ${new_state} ]; then echo ${new_state} > "${SYSTEM_GPIO}/gpio${GPIO_PF6}/value" fi exit 0