Adafruit mini 07prime 8x8 led matrices with i2c backpack adafruit 1633 the adafruit green mini 07 8x8 led matrices take the pain out of using matrix displays by including an i2c backpack to do the constant current driving and multiplexing connecting displays like this can be quite expensive in precious gpio pins but with the added backpack they only use the 2 x i2c signals plus 2 x power connections they are great for microcontrollers with limited outputs such as the adafruit trinkets