Example for the Demoboard - Using the 4 OUTPUT pins
First make sure the board is properly attached to the pilot mainboard. You may use screws to make sure the board will be 100% accurateley in place.
The board comes with 4 OUTPUT pins. They are labeled O0,O1,O2 and O3
To switch on the pins you need to enable the GPIO chip and write a positive value to the output filedescriptor.
When the module is plugged in slot 1 the GPIO offset for the outputs is 59
echo 59 > /sys/class/gpio/export echo 60 > /sys/class/gpio/export echo 61 > /sys/class/gpio/export echo 62 > /sys/class/gpio/export
Now the 4 OUTPUT pins are available on the Linux host.
Next we must define them as outputs
echo out > /sys/class/gpio/gpio59/direction echo out > /sys/class/gpio/gpio60/direction echo out > /sys/class/gpio/gpio61/direction echo out > /sys/class/gpio/gpio62/direction
Now we can turn the pin on
echo 1 > /sys/class/gpio/gpio59/value echo 1 > /sys/class/gpio/gpio60/value echo 1 > /sys/class/gpio/gpio61/value echo 1 > /sys/class/gpio/gpio62/value
.. and off
echo 0 > /sys/class/gpio/gpio59/value echo 0 > /sys/class/gpio/gpio60/value echo 0 > /sys/class/gpio/gpio61/value echo 0 > /sys/class/gpio/gpio62/value
The leds on those ports are also turned on when you enable the pin.
You can use these pins to control external hardware like a small motor, leds, a buzzer or other external electronic components.
The pin outputs +5V when high and is at the ground potential when low.