Enhancement of IO-Port#1 and IO-Port #2
The ODROID-U3 provides two expansion sockets.
Easy to use GPIOs
First, you refer to below link.
You check Export number that you want to use GPIO.
Create a GPIO file access.
You can access GPIOs using sysfs interface.
echo 199 > /sys/class/gpio/export
Configure the pin direction (in/out)
echo out > /sys/class/gpio/gpio199/direction
Write a value (1/0)
echo 1 > /sys/class/gpio/gpio199/value