Adafruit Trellis Monochrome Driver PCB for 4x4 Keypad & 3mm LEDs

The Trellis driver PCB assembly forms the backbone of an open-source backlight keypad system. Designed with versatility in mind, it accommodates any 3mm LEDs and seamlessly connects up to eight tiles on a shared I2C bus. Tailored to complement the Adafruit 4x4 elastomer keypad, each PCB features an array of 4x4 pads ready for LED integration.

Featuring an I2C-controlled LED sequencer, the assembly offers precise control over individual LEDs without grayscale or dimming options. The on-board circuitry manages key-press background handling and LED lighting, while unique diode multiplexed connections prevent ghosting during multi-key presses.

Solder-friendly edge connectors enable easy tiling of multiple PCBs, supporting extensive layouts of up to 128 buttons or LEDs using just two I2C wires. This flexibility allows countless configurations, making the Trellis an adaptable solution for interactive projects.

Ideal for combining colorful LED displays, the assembly supports varied LED colors, with diffused LEDs offering optimal aesthetic outcomes. The PCB requires an external microcontroller, such as an Arduino, for complete functionality, supported by available libraries and tutorials.