Chroma Sudoku
Color-based Sudoku for embedded hardware
Links: GitHub
Recognition: 2nd Place—Purdue SPARK Challenge 2025
I like sudoku. I like programming. Sometimes, I even program sudoku.
That usually works out—until you try to fit 81 numbers onto a 32×32 RGB LED matrix.
The Problem
Digital sudoku breaks down at very small scales. Arabic numerals are pixel-hungry, and at this resolution reading them becomes the main challenge instead of the puzzle itself.
The image exhibits some exposure effects that do not appear on the physical board.
The Idea
Instead of digits, ChromaSudoku uses nine distinct colors. On a 32×32 RGB matrix, color blocks remain instantly distinguishable without any text rendering. Each cell maps directly to a color, eliminating glyph complexity while preserving the core logic of Sudoku.
Implementation
ChromaSudoku runs on an RP2350 and is written in C using PlatformIO.
The grid, input handling, and validation logic are all designed around tight memory and timing constraints typical of embedded systems.
What I Learned
- Designing interfaces for extreme resolution limits
- Rethinking familiar problems under hardware constraints
