Merge pull request #1 from SWW13/v1-led-sh

V1: led.sh

V1/led.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+# usage: led.sh <port>
+set -o xtrace
+
+# config default
+GPIO_PORT="${1:-18}"
+
+function export_port() {
+  port="${1}"
+  echo "${port}" > /sys/class/gpio/export
+}
+function unexport_port() {
+  port="${1}"
+  echo "${port}" > /sys/class/gpio/unexport
+}
+
+function set_direction() {
+  port="${1}"
+  value="${2}"
+  echo "${value}" > "/sys/class/gpio/gpio${port}/direction"
+}
+
+function set_value() {
+  port="${1}"
+  value="${2}"
+  echo "${value}" > "/sys/class/gpio/gpio${port}/value"
+}
+
+function on() {
+  port="${1}"
+  set_value "${port}" "0"
+}
+function off() {
+  port="${1}"
+  set_value "${port}" "1"
+}
+
+# set exit trap
+trap 'unexport_port "${GPIO_PORT}"' EXIT
+
+# init GPIO port
+export_port "${GPIO_PORT}"
+set_direction "${GPIO_PORT}" "out"
+
+# loop led on/off
+while true; do
+  on "${GPIO_PORT}"
+  sleep 1
+  off "${GPIO_PORT}"
+  sleep 1
+done