Access General Purpose I/O port on FriendlyARM

    To access General Purpose I/O port on FriendlyARM, follow the procedure given below.

Open terminal on FriendlyARM:

cd sys/class/gpio                   // go to gpio

echo 36 > export                  // enable pin 36 of i/o port

echo out > gpio36/direction  // out for output. It makes pin 36 of I/O port as output pin

echo 1 > gpio36/value          // 1 for high, 0 for low

echo 36 > unexport              //disable

Check by using DMM or by LED. Output voltage should 3.3V