These displays get their name because of the controller chip attached to the back of them like a backpack.
7 segment led ht16k33 backpack.
This ht16k33 controller can drive up to 128 multiplexed leds in matrix bar graph 7 segment numeric and even 14 segment alpha numeric.
Led backpack displays are a great way to add a simple bright led display to your project.
These 7 segment displays normally require 13 pins 5 characters and 8 total segments each this backpack solves the annoyance of using 13 pins or a bunch of chips by having an i2c constant current matrix controller sit neatly on the back of the pcb.
The 7 segment displays normally require 16 pins to drive.
These backpacks drive the massive 1 2 7 segment modules.
This backpack uses an i2c constant current matrix controller on the back of the pcb so you only need 2 pins to drive it.
Adafruit led backpack library for our 8x8 matrix and 7 segment led backpacks adafruit adafruit led backpack.
With 2 leds per segment these make a gorgeous and impressive display.
The functions included in this demo sketch should be all that s needed to control the ht16k33 s led matrix from an arduino.
A fun way to make a small display is to use an 8x8 matrix or a 4 digit 7 segment display.
Adafruit industries unique fun diy electronics and kits adafruit 0 56 4 digit 7 segment display w i2c backpack yellow id.
879 what s better than a single led.
As the ht16k33 communicates via i2c you only need two gpios.
For the demo sketch i m using a 16 bit buffer which makes each array element correspond to all outputs for a given com pin you could also use an 8 bit buffer which would make things easier if i only had 7 segment displays.
The ht16k33 led driver chip can control up to 16 x 8 leds.
This is the magic sauce in our 7 segment and matrix backpacks now available in breadboard friendly breakout board format.
There are maker friendly modules available with 7segment leds 14segment leds dot matrix and even blank pcb als simple backpacks for your own project.