Adafruit 1.2" 4-Digit 7-Segment Display w/I2C Backpack - Red

Key Features Big 1.2" 4-digit 7-segment display Backpack has built-in clock that will multiplex the display for your Ultra bright, consistent red color display Connect up to eight 7-segments (or a combination, such as four mini 8x8's and four 7-segments, etc) on a single I2C bus What's better than a single LED? Lots of LEDs! A fun way to make a numeric display is to use a 4-digit 7-segment display. LED 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. 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 backpacks 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 our 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 (or a combination, such as four mini 8x8's and four 7-segments, etc) on a single I2C bus.Item Specifics1 - Fully tested and assembled LED backpack1 - Ultra bright 4-digit 1.2" tall red 7-segment display1 - 5-pin headerSome soldering is required to attach matrix to backpackMounted measurements:  50mm/2" W x 120mm/4.7" L x 13mm/0.5" HThis board/chip uses I2C 7-bit addresses between 0x70-0x77, selectable with jumpers.