Enhancement of 40pin GPIO

The ODROID-C2 provides 40Pin GPIOs.

First, you refer to below link.
You check Export number that you want to use GPIO.
Pin description

You need to enter into super-user mode first to run below commands !!

 sudo su 

Create a GPIO file access.
You can access GPIOs using sysfs interface. This example uses pin number 18 which is connected to the GPIO233(GPIOX.BIT5).

  echo 233 > /sys/class/gpio/export

Configure the pin direction for input

  echo in > /sys/class/gpio/gpio233/direction

Configure the pin direction for output

  echo out > /sys/class/gpio/gpio233/direction

Read a value (if gpio direction is input)

  cat /sys/class/gpio/gpio233/value

Write a value (if gpio direction is output)

  echo 1 > /sys/class/gpio/gpio233/value : gpio high
  echo 0 > /sys/class/gpio/gpio233/value : gpio low