Hi there!

This is my first project that I post on hackaday.

Example of working

Attiny13 have onboard 1 kBytes of Flash memory.

Program you see on video use only 882 byte of memory. It means that you can write message 100+ char long. If you off tests of pixel moving and line size of code 522. Almost ~500 chars text.

Attiny13 drive 20 LEDs by 5 pin;s. Let's look at the scheme:

This is "charlieplexing" you can read more on wikipedia.

In every moment of time you can only "on" 2 or 3 LEDs. What you need to do for switching "on" all leds? You must switch on every LED for small part of time.

You can see working version in commit "01940c8". I plan optimize code: remove duty cycle delays and use timers and sleep sequential. Work in progress.

Also on Github you can download all source and schematics with PCBs design. Also BOM list.