Using Raspberry Pi GPIO pins directly

The Raspberry Pi can also perform input and output without an Arduino board. But the General-Purpose Input/Output (GPIO) pins available only supports digital input and output. Since the relay module is controlled through a digital output, we can connect it directly to the Raspberry Pi, if we want. That way, we don't need the Arduino board. (We wouldn't be able to test-run the application on the local machine either, though.)

Checking whether GPIO is available

GPIO pins are accessed through the GpioController class defined in the Windows.Devices.Gpio namespace. First, we must check that GPIO is available on the machine. We do this by getting the default controller, and checking whether it's available:

gpio = GpioController.GetDefault(); 
if (gpio != null) 
{ 
   ... 
} 
else 
   Log.Error("Unable to get access to GPIO pin " +
          gpioOutputPin.ToString()); 

Initializing the GPIO output pin

Once we have access to the controller, we can try to open exclusive...