This is just a quick heads-up to let you know that I’m working on a MAX7219 library for NodeMCU. In October last year I first experimented with MAX7219 8×8 matrix displays. Ever since then I wanted to create a library that would support daisy-chained displays and a few text animations. I finally kicked myself in the butt and started tinkering.
The library will allow you to
- define number of displays you connected
- set characters as bytes
- set text and a font table (8 bytes per char)
- scroll the text left and right
- oscillate text
- rotate and invert individual characters
That last feature is quite important for daisy-chained displays. Depending on the module and how they’re chained characters may have to be transformed to appear as you expect them to.
Text displayed on 4-in-1 modules must be rotated left by 90°. If you daisy-chain the standalone modules manually no rotating is necessary but you may want to invert the characters to turn your chain up-side down.
The library is on GitHub at https://github.com/marcelstoer/nodemcu-max7219 and I invite you give it a try. I appreciate if you create an issue on GitHub should you run into problems. General remarks are very welcome here, however.