Scrolling text with a @Raspberry_Pi and LED Matrix #piday #raspberrypi
Mark’s Space has a great tutorial on how to scroll text across a matrix with a Raspberry Pi.
A friend requested if it was possible to scroll text across three 8×8 LED matrices, specifically this type from Adafruit, which are very bright.
So, I got to work.
These matrices uses a HT16K33 controller chip and communicate with the Pi via the i2c bus.
Adafruit have very good and detailed tutorials on how to solder it up and get i2c working between your Pi and your matrices.
Since we are having multiple matrices using the same i2c bus, we need to make sure that each uses a unique address. By default they will have 0×70 (hexadecimal notation). This value can be changed by brindgin the gap on some copper pads on the back of the matrix.
Adafruit Mini 8×8 LED Matrix w/I2C Backpack – Blue – What’s better than a single LED? Lots of LEDs! A fun way to make a small display is to use an 8×8 matrix or a 4-digit 7-segment display. 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. Here at Adafruit we 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. We have them in two flavors – a mini 8×8 and a 4-digit 0.56″ 7-segment. They work perfectly with the matrices we stock in the Adafruit shop and make adding a bright little display trivial. Read more.
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.