Doubt with lines

I have some questions about the lines in the project examples. What is the exact function in this line?


Thank You.

The UART communication protocol uses addresses to address each of the BrickPi microcontrollers (2 per BrickPi). In the RPi C program, you need to tell what addresses the BrickPi microcontrollers are using (thus those two lines).

The BrickPi microcontroller addresses are 1 and 2 when the BrickPi ships, but they can be changed if necessary.