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. Control a matrix without tons of wiring with these lovely LED matrix backpacks.
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 are photographed at the dimmest setting to avoid overloading the camera), 1/16 step display dimming, all via a simple I2C interface. These 1.2"" matrix backpacks come with three address-selection jumpers so you can connect up to eight 1.2"" 8x8's together (or a combination, such as four 1.2"" 8x8's and four 7-segments, etc) on a single I2C bus.Kit includes:
- Fully tested and assembled 1.2"" LED backpack
- Ultra-bright 1.2"" 8x8 blue 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.