To control on the GPIO pins:
The external GPIOs are available under the /sys/class/gpio folder in Linux.
To control on the GPIO pins you need to calculate the GPIO number XX and run the commands below:
# Export GPIO XX echo XX > /sys/class/gpio/export # Set GPIO pin Direction echo "out" > /sys/class/gpio/gpioXX/direction or echo "in" > /sys/class/gpio/gpioXX/direction # Set the value of an output pin echo 1 > /sys/class/gpio/gpioXX/value or echo 0 > /sys/class/gpio/gpioXX/value # Get the value of an input pin cat > /sys/class/gpio/gpioXX/value # Unexport GPIO XX echo XX > /sys/class/gpio/unexport |
This is an example code for accessing the GPIOs on the ClearFog Base/Pro:
#An example for gpio 22 # Export GPIO XX cd /sys/class/gpio/ echo 22 > export cd gpio22/ # Set GPIO pin Direction echo out > direction # Set the value of an output pin echo 0 > value |