Modifying the main.cpp file

To complete your application, the main.cpp file should also be modified to process the data on the virtual pin. These steps show you how to modify it with the nano editor:

1. Open the main.cpp file with nano by issuing the following command:

pi@raspberrypi:~/blynk-library/linux $ sudonanomain.cpp

main.cpp opened with nano editor

2. Before using the WiringPi GPIO library, you need to include its header file in your program as follows:

#include <wiringPi.h>

3. Scroll down to the file with the arrow keys on your keyboard and add the following code to the setup() function:

void setup()
{
Blynk.begin(auth, serv, port);
pinMode(1, OUTPUT);
}

The pinMode() function allows you to set the mode of a pin to either INPUT, OUTPUT, or PWM_OUTPUT. Note that only WiringPi pin 1 (BCM_GPIO 18) supports PWM output.

4. Then, add the following lines to the BLYNK_WRITE(V1...