Amazon.com: RP2040 RGB LED Matrix Tiny MCU Board Based On Raspberry Pi RP2040 Microcontroller Chip with 5×5 RGB LED Matrix for Colorful Lighting Display, with USB Type-C Port,Support Arduino,C/C++, MicroPython : Electronics
Adafruit RGB Matrix Shield for Arduino : ID 2601 : $5.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Arduino Tutorial - Lesson 3 - Breadboards and LEDs
Arduino 8x8 LED Matrix Project with Circuit Diagram & Code
LED Display Board using P10 LED Matrix Display and Arduino | Led matrix, Arduino, Led display board
Matrix & Sprite Arduino Libraries, for a many-LED display!