What's better than a single LED? Lots of LEDs! A fun way to make a small display is to use an 8x8 matrix or a 4-digit 7-segment display. Matrices like these are 'multiplexed' - so to control 64 LEDs you need 16 pins. That's a lot of pins, and there are driver chips like the MAX7219 that can control a matrix for you but there's a lot of wiring to set up and they take up a ton of space. Here at Adafruit we feel your pain! After all, wouldn't it be awesome if you could control a matrix without tons of wiring? That's where these adorable LED matrix backpacks come in. We have them in two flavors - 8x8 matrix and a 4-digit 7-segment display. They work perfectly with the matrices we stock in the Adafruit shop and make adding a bright little display trivial. The matrices use a driver chip that does all the heavy lifting for you: They have a built in clock so they multiplex the display. They use constant-current drivers for ultra-bright, consistent color (the images above are photographed at the dimmest setting to avoid overloading our camera!), 1/16 step display dimming, all via a simple I2C interface. The backpacks come with address-selection jumpers so you can connect up to four mini 8x8's or eight 7-segments (or a combination, such as four mini 8x8's and four 7-segments, etc) on a single I2C bus. The product kit comes with: * A fully tested and assembled LED backpack * Ultra-bright 8x8 yellow matrix * 4-pin header A bit of soldering is required to attach the matrix onto the backpack but its very easy to do and only takes about 5 minutes. Of course, in classic Adafruit fashion, we also have a detailed tutorial showing you how to solder, wire and control the display. We even wrote a very nice library for the backpacks so you can get running in under half an hour, displaying images on the matrix or numbers on the 7-segment. If you've been eyeing matrix displays but hesitated because of the complexity, his is the solution you've been looking for!Technical Details * This board/chip uses I2C 7-bit address between 0x70-0x77, selectable with jumpers Backpack Dimensions: * 20mm x 28mm x 4mm / 0.8" x 1.1" x 0.2" * Mounting Holes: 12mm x 22mm / 0.5" x 0.9" Datasheets, schematic, EagleCAD PCB files, and Fritzing available in the product tutorial https://elecena.pl/product/22713774/adafruit-mini-8x8-led-matrix-with-i2c-backpack-yellow 2023-03-06 https://elecena.pl/product/22713774/adafruit-mini-8x8-led-matrix-with-i2c-backpack-yellow 2023-12-27 https://elecena.pl/product/22713774/adafruit-mini-8x8-led-matrix-with-i2c-backpack-yellow 2024-09-19 https://elecena.pl/product/22713774/adafruit-mini-8x8-led-matrix-with-i2c-backpack-yellow 2024-11-29 https://elecena.pl/product/22713774/adafruit-mini-8x8-led-matrix-with-i2c-backpack-yellow 2024-11-30 https://elecena.pl/product/22713774/adafruit-mini-8x8-led-matrix-with-i2c-backpack-yellow 2025-11-28 https://elecena.pl/product/22713774/adafruit-mini-8x8-led-matrix-with-i2c-backpack-yellow 2025-11-29