Looking for a cool way to create a numeric display? Well, multiple LEDs are way better than a single one! A 4-digit 7-segment display is a fun choice. These LED matrices are multiplexed, usually needing 14 pins to control all the seven-segment LEDs. That's a lot of pins! There are driver chips like the MAX7219, but they require a lot of wiring and take up a ton of space. At Adafruit, we get your frustration! What if you could control a matrix without all that wiring? That's where our cute LED matrix backpacks come in. We have them for various 8x8 and 7-segment displays. They work great with the displays in our Adafruit shop, making it super easy to add a bright display. The backpacks use a driver chip that does all the hard work. They have a built-in clock for display multiplexing, and constant-current drivers for ultra-bright, consistent color. You can adjust the display brightness in 1/16 steps via a simple I2C interface. The backpacks come with address-selection jumpers, allowing you to connect up to eight 7-segments or a combination of different displays on a single I2C bus. The product kit includes a fully tested and assembled LED backpack, an ultra-bright 1.2-inch tall yellow seven-segment display, and a 5-pin header. A bit of soldering is needed to attach the matrix to the backpack, but it's very easy and only takes about 5 minutes. We also have a detailed tutorial on soldering, wiring, and controlling the display. We've written nice libraries for the backpacks, so you can start displaying numbers on the 7-segment for Arduino or Raspberry Pi in under half an hour. If you've been hesitant about matrix displays due to complexity, this is the perfect solution!
Using this product is a breeze. First, you'll need to do a bit of soldering to attach the 4-digit 7-segment display to the LED backpack. It only takes about 5 minutes, and we have a detailed tutorial to guide you through the soldering process. Once it's soldered, you can connect it to your Arduino or Raspberry Pi using the 5-pin header. The backpack uses a simple I2C interface, so wiring is straightforward. You can then use the libraries we've written to start displaying numbers on the 7-segment display in under half an hour. When it comes to adjusting the brightness, you can do it in 1/16 steps via the I2C interface. As for maintenance, keep the display and backpack clean and free from dust. Avoid exposing it to extreme temperatures or moisture. If you need to connect multiple displays, use the address-selection jumpers on the backpack to connect up to eight 7-segments or a combination of different displays on a single I2C bus.
