Project Structure

PROS projects are internally composed of three parts: the PROS library (found in /firmware), the header files (found in /include), and user code (found in /src).


The PROS library is a single file containing the core PROS routines. This file does not need to be changed. If there appears to be an issue with a core PROS function, please file an issue on GitHub.


The header files are all found in the include directory. One header file, api.h, is required to declare the PROS library functions. This file exists merely to include the individual PROS API headers, all of which can be found in include/pros. Each header file in this directory covers a specific aspect of interacting with the V5 hardware, and correlates to the files found in the API documentation.

The other file, main.h, is intended for declaring functions and variables shared between the user code files. main.h also offers a variety of configurable options for tailoring PROS to your needs.

  • PROS_USE_SIMPLE_NAMES: If defined, some commonly used enums will have preprocessor macros which give a shorter, more convenient naming pattern. For instance, E_CONTROLLER_MASTER has a shorter name: CONTROLLER_MASTER. E_CONTROLLER_MASTER is pedantically correct within the PROS styleguide, but not convenient for most student programmers.
  • using namespace pros: This can be uncommented to be added with the use of PROS_USE_SIMPLE_NAMES. This reduces the length of declarations when using C++, allowing you to simply declare a Motor instead of a pros::Motor. This will make the code appear cleaner and will be simpler for newer programmers, but is typically considered bad practice. As a result, this line is commented out by default.

New header files can be created in the include directory, as long as the name ends with .h (Traditionally for C files) or .hpp (for C++ files). See this C++ tutorial for more information on how to create header files.


User code has the actual sequential instructions that govern the robot’s behavior. Prior to PROS kernel 3.2.0, new projects by default split user code into autonomous (autonomous.c or autonomous.cpp), driver control (opcontrol.c or opcontrol.cpp), and initialization (initialize.c or initialize.cpp) files. Code in one file can talk to code in another file using declarations in the header files. Beginning with PROS kernel 3.2.0, new projects by default have a single main.cpp file that contains all of the competition task functions.

New user code files can be created in the src directory, as long as the name ends with .c or .cpp it will be compiled with the others.

All user code files should start with:

#include "main.h"

This will ensure that the PROS API and other critical definitions are available in each file.

While more complicated than some environments, splitting up code grants powerful modularity and code reusability, especially when combined with source control.