Before using the WiringPi GPIO library, you need to include its header file in your programs:

#include <wiringPi.h>

You may also need to add

-I/usr/local/include -L/usr/local/lib -lwiringPi

to the compile line of your program depending on the environment you are using. The important one is -lwiringPi

You may also need additional #include lines, depending on the modules you are using.

Reference/API Pages

• WiringPi Setup functions
• Core wiringPi functions

These two above are the most important features of wiringPi. Below are additional functions and libraries that comprise the main wiringPi release.

• Raspberry Pi specific functions
• Timing functions
• Program priority, timing and threads
• Serial library
• SPI library
• I2C library
• Shift library
• Software PWM library
• Software tone library