What’s better than a single LED? Lots of LEDs! A fun way to make a small display is to use an 8×8 matrix or a 4-digit 7-segment display. Matrices like these are ‘multiplexed’ – so to control all the seven-segment LEDs you need 14 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 – a mini 8×8 and a 4-digit 0.56″ 7-segment. They work perfectly with the matrices we stock in the Adafruit shop and make adding a bright little display trivial. The product kit comes with: A fully tested and assembled LED backpack Ultra-bright 4-digit 0.56″ tall seven-segment display 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, this is the solution you’ve been looking for!
Multiplexed 4 digit 7-Segment Ultra Bright Display
I2C Backpack (Requires Soldering) that allows the display to be driven with just 4 pins!
Setup guide and Arduino libraries available from Adafruit