i2c Square Bi-colour LED Matrix
What's better than a single LED? Lots of LEDs! A fun way to make a small colorful display is to use a 1.2" Bi-color 8x8 LED Matrix. Matrices like these are 'multiplexed' - so to control all the 128 LEDs you need 24 pins. That's a lot of pins, and there are driver chips like the MAX7219that can help 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 three flavors - a mini 8x8, 1.2" Bi-color 8x8 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. It's called a Bicolor LED, but you can have 3 colors total by turning on the red and green LEDs, which creates yellow. That's 3 colors for the price of 2!
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, 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/bicolor (or a combination, such as four mini 8x8's and two 7-segments and two bicolor, etc) on a single I2C bus.
The product kit comes with:
- A fully tested and assembled LED backpack
- 1.2" Bi-color 8x8 LED 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 wrotea 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!