When we last heard from [lixielabs] he was building Nixie tube replacements out of etched acrylic and LEDs. Well he’s moved forward a few decades to bring us the Pixie, a chainable, addressable backpack for tiny LED matrix displays.

Each Pixie module is designed to host two gorgeous little Lite-On LTP-305G/HR 5×7 LED dot matrix displays, which we suspect have been impulse purchases in many a shopping cart. Along with the displays there is a small matrix controller and an ATTINY45 to expose a friendly electrical interface. Each module is designed to be mounted edge to edge and daisy chained out to 12 or more (with two displays each) for a flexible display any size you need. But to address the entire array only two control pins are required (data and clock).

[lixielabs] has done the legwork to make using those pins as easy as possible. He is careful to point out the importance of a good SDK and provides handy Arduino libraries for common microcontrollers and a reference implementation for the Raspberry Pi that should be easy to crib from to support new platforms. To go with that library support is superb documentation in the form of a datasheet (complete with dimensions and schematic!) and well stocked GitHub repo with examples and more.

To get a sense of their graphical capabilities, check out a video of 6 Pixie’s acting as a VU meter after the break. The Pixie looks like what you get when a hacker gets frustrated at reinventing LED dot matrix control for every project and decided to solve it once and for all. The design is clean, well documented, and extremely functional. We’re excited to see what comes next!

ESP32 with an I2S mic running FFT with 1024 cells, with each octave overlaid to make a 12-note chromagram, being rendered live by Pixies!https://t.co/0nWQfX0W6W pic.twitter.com/UZgh5ymWAw

— Lixie Labs (@lixielabs) September 22, 2020

Read the full article on MAKE

When you don’t want to use I2C or SPI, and MIDI and DMX are old hat, [Scott] comes along and invents a very strange networking protocol that is just daisy chaining a few Arduinos together with serial connections.

Strange as it may seem, this networking protocol actually makes a whole lot of sense. [Scott] is working on an animatronic birdhouse in the vein of Disney’s Imagineers and needed to network a whole bunch of Arduinos without using up precious IO pins.

The networking stack [Scott] came up with capitalizes on the hardware UART in each Arduino by simply daisy-chaining several boards together. By adding an FTDI breakout at the beginning of the chain, [Scott] can control dozens of Arduinos straight from a terminal

[Scott] isn’t using off-the-shelf Arduinos for this project – a few months ago he found 100 Arduino-compatible stepper motor controllers while dumpster diving at his job, giving him more than enough nodes to come up with some pretty crazy networking protocols. It’s a great use of the hardware he has on hand, and a very clever solution to controlling dozens of microcontrollers at once.

Check out [Scott]‘s demo after the break.