Snake game

We're now going to implement a basic snake game that you can play on an MB2 using its 5×5 LED matrix as a display and its two buttons as controls. In doing so, we will build on some of the concepts covered in the earlier chapters of this book, and also learn about some new peripherals and concepts.

Modularity

The source code here is more modular than it probably should be. This fine-grained modularity allows us to look at the source code a little at a time. We will build the code bottom-up: we will first build three modules — game, controls and display, and then compose these to build the final program. Each module will have a top-level source file and one or more included source files: for example, the game module will consist of src/game.rs, src/game/coords.rs, src/game/movement.rs, etc. The Rust mod statement is used to combine the various components of the module. The Rust Programming Language has a good description of Rust's module system.