diff --git a/V1/led.sh b/V1/led.sh
index 45fade7..a0033e7 100755
--- a/V1/led.sh
+++ b/V1/led.sh
@@ -14,6 +14,12 @@ function unexport_port() {
   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}"
@@ -34,6 +40,7 @@ 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