I built an LED matrix controlled by an ESP32C6 Supermini. The challenging part was determining the size of the matrix and the IC that would control it. Initially, I wanted to make it 9x9, but due to design complexity and the capabilities of the HT16K33, I had to make it 7x7. I adjusted the ground plane on the PCB to avoid reducing the wireless communication range of the ESP32C6 board.