This is the magic sauce in our 7-segment and matrix backpacks, now available in breadboard-friendly breakout board format. The HT16K33 is a neat little chip that has the ability to drive a multiplexed 16x8 matrix (that's 128 individual LEDs). The communication protocol is I2C so it uses only 2 pins, and you can have up to 8 selectable I2C addresses so thats a total of 8 matrices, each one controlling 16x8 LEDs for 1024 total LEDs.

Unlike our LED matrix/segment backpacks, this breakout does not have holes for an existing LED module. Instead, we break out all 16 anodes and 8 cathodes as well as the I2C and power pins. You'll need to wire up the anodes and cathodes by checking out your matrix datasheet and lining up the pins. Wire up any matrix you want and use our handy library to write to the display however you wish. Note that the driver can turn LEDs on and off but does not have the ability to individually PWM dim them. This chip is rock solid, has Arduino & Pi example code written for it and is easy to use.

The chip supports also reading a 3x13 keypad matrix but we do not have example code for it in our library, check the datasheet for more details about the keypad functionality

Adafruit 16x8 LED Matrix Driver Backpack - HT16K33 Breakout (3:16)