LED Matrix Controller

A custom-designed PCB and firmware for controlling a 16x16 WS2812B addressable LED matrix, powered by an ESP32.

Overview

Built a hardware controller from scratch:

• PCB designed in KiCad — 2-layer board with ESP32-WROOM module, level shifter for the data line, and screw terminals for power
• Firmware in C++ — runs animation patterns, responds to serial commands, supports OTA updates
• Power management — proper decoupling, bulk capacitance, and current limiting for 256 LEDs

Lessons Learned

1. Always add test points to your PCB — debugging without them is painful
2. WS2812B timing is tight — use hardware SPI or a dedicated library, not delayMicroseconds()
3. 256 LEDs at full white draws ~15A — plan your power supply accordingly

This was my first custom PCB project. The first revision had a footprint error on the level shifter. The second revision worked perfectly.