With the 16x8 LED Matrix we've doubled your project's matrix capacity by making it super easy to get two separate 8x8 matrices onto one handy board! This version of the LED backpack is designed for two of the 1.2" 8x8 matrices. They measure only 1.2"x1.2" so its a shame to use a massive array of chips to control it. This backpack solves the annoyance of using 32 pins or a bunch of chips by having an I2C constant-current matrix controller sit neatly on the back of the PCB. The controller chip takes care of everything, drawing all 128 LEDs in the background. All you have to do is write data to it using the 2-pin I2C interface. There are two address select pins so you can select one of 8 addresses to control up to 8 of these on a single 2-pin I2C bus (as well as whatever other I2C chips or sensors you like). The driver chip can 'dim' the entire display from 1/16 brightness up to full brightness in 1/16th steps. It cannot dim individual LEDs, only the entire display at once.

Assembling the 1.2" 16x8 backpack is nearly the same as the 1.2" 8x8, so you can follow that page for directions, only difference is there’s two matrices to install now.

The printed-on edge of the matrices face the white dots on the PCB, and there’s a single set of address selection pads; the pair is addressed as one larger unit, not set independently.