Ever wonder who is forking your code? [Jack] did, so he built a real time GitHub activity display for his company’s repositories. The display is based a Wyolum The Intelligent Matrix (TiM) board. The TiM is an 8 x 16 matrix of the ubiquitous WS2811/Smart Pixel/NeoPixel RGB LEDs with built-in controller. We’re seeing more and more of these serial LEDs as they drop in price. Solder jumpers allow the TiM to be used as 8 parallel rows of LEDs (for higher refresh rates), or connected into one long serial chain.
[Jack] wasn’t worried about speed, so he configured his board into a single serial string of LEDs. An Arduino drives the entire matrix with a single pin. Rather than reinvent the wheel, [Jack] used Adafruit’s NeoMatrix library to drive his display. Since the TiM uses the same LEDs as the Adafruit NeoPixel Matrix, the library will work. Chalk up another victory for open source hardware and software!
An Electric Imp retrieves Github data via WiFi and passes it on to the Arduino. This is a good use of a microcontroller such as the AVR on the Arduino. [Jack’s] display has a scrolling username. Every step in the scroll animation requires all the pixel data be clocked out to the TiM board. The Arduino can handle this while the IMP takes care of higher level duties.
GitHub actions are represented by colored pixels forming the background of the display. The username of the last user to touch the repository is scrolled across the display. It’s a bit hard to translate the background matrix colors to activities without some sort of key. We’re guessing this would become second nature after the display is in use for a few days. We don’t know if [Jack’s] company does any automated build testing, but we would love to see his project merged with this traffic light build monitor. A big bright red LED matrix with a white scrolling user name would leave no question who broke the build – and who is going to be working late to fix it!
The next sw release of the imp has better fast SPI support which allows you to drive neopixels direct from the imp, so no need for two CPUs :)
(I’m from electric imp)
The 8×16 RGB LED array TiM is available here: http://www.seeedstudio.com/depot/tim-p-1516.html