What's better than a single LED? Lots of LEDs! A fun way to make a small display is to use 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.
At Adafruit they 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.
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 the 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 eight 7-segments on a single I2C bus.
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, they also have a detailed tutorial showing you how to solder, wire and control the display. They 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!
This board/chip uses I2C 7-bit address between 0x70-0x77, selectable with jumpers
- Backpack Dimensions: 27mm x 50mm x 4mm / 1.1" x 2" x 0.16"
- Backpack Weight: 5.3g
- 7-Segment Display Dimensions: 19mm x 50mm x 14mm / 0.75" x 2" x 0.56"
- 7-Segment Display Weight: 8.4g
We no longer stock this product
It's sad to say goodbye but sometimes we have to retire products to make way for new things.
You may still be able to buy this product directly from our friends at Adafruit - check out their website!