What is it? This is a take on the famous Knight Rider KITT scanner (aka Larson Scanner)

Why did you make it? It is fun! Need more reason?

What makes it special? It uses a compact pcb with 20x 3520 LED consumes little power and is microUSB powered.

This is a project based on the work of Luc Volders, in his 4 part article on charlieplexing. The article explains in detail all you need to know about charlieplexing and how to make/program your own Larson Scanner LEDs, inspired by KITT from the Knight Rider series.

Luc Volders Charlieplexing Article

How many LEDs? 20 LEDs How much current? around 60mA@5V 26mA@3.7V 15ma@3V, tested down to 2V drawing barely 3mA obviously with much reduced LED brightness.

What kind of power supply needed? Any microUSB 5V source will be just fine. 2x AA in series would also be an excellent choice if reduced brightness is acceptable