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:
- Open the
main.cppfile with nano by issuing the following command:
pi@raspberrypi:~/blynk-library/linux $ sudonanomain.cpp
main.cpp opened with nano editor
- Before using the
WiringPi GPIOlibrary, you need to include its header file in your program as follows:
#include <wiringPi.h>
- 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.
- Then, add the following lines to the
BLYNK_WRITE(V1)function. This code snippet will compare the value on virtual pin V1 and write values on BCM_GPIO 18 pin (WiringPi pin 1) as...
