This diagram uses the Gemma v2 but you can also use the Gemma M0 with the exact same wiring!

Gemma + 8x8 LED Matrix

Using the GEMMA in this build allows us to plug in a rechargeable battery directly into the JST port is directly on the board. GEMMA can be powered by USB but will need to have a battery power source for portability.

  • VCC pin goes to VBAT
  • GND pin goes to GND
  • SCL pin goes to D2/A1
  • SDA pin goes to D0


If your new to working with GEMMA, be sure to use a breadboard and jumper wires to prototype. Use alligator clips to clip jumper wires to GEMMA. The 8x8 LED matrix w/backpack will need header + pins soldered to the breakouts. Check out the adafruits guide to LED backpacks for more details.

This guide was first published on Feb 20, 2014. It was last updated on Nov 27, 2023.

This page (Circuit Diagram) was last updated on Feb 17, 2014.

Text editor powered by tinymce.