12 LED KITT-scanner / Cylon-eye with trail effect
The famous visual effect from the TV-series Battlestar Galactica and Knight Rider

Download the ATtiny15L datasheet.
Download the ATtiny13 datasheet.

A 12 LED KITT scanner with trail. Often this kind of gadgets have no trail effect, but just a single LED moving visually back and forth. In the TV-series Knight Rider or Battlestar Galactica you saw clearly a trail effect in the visual motion, the same way you see in the gif animation on this webpage. Here one with a trail effect, using an ATtiny15L or ATtiny13 AVR microcontroller, the applied technique called charlieplexing.

Part list: 1x ATtiny15L or ATtiny13 2x 1N4007 1x 78L05 12x low-current LED 4x 47 ohm 1x 10k 2x 100n 1x 47uF/16V

Download this *.hex file, and dump it into an ATtiny15L AVR microcontroller with e.g. this programmer. For the ATtiny13 use this *.hex file. Have fun!

Prototype of the KITT-scanner on a small piece of veroboard

Diagram of the 12 LED charlieplexed KITT-scanner / Cylon-eye (without speed adjust)

A 20 LED circular effect
A tiny 20 LED circular effect

Download the ATtiny12 datasheet.

The circuit diagram 20 LED effect

A 20 LED circular effect. On the right a diagram of twenty charlieplexed LEDs. Only five i/o ports of an ATtiny12 microcontroller and five 47 Ω resistors are used to drive these twenty LEDs. In this example the LEDs are placed in a circle and showing multiple light effects. (program under construction)

A round 20 LED effect (charlieplexed)

Short movie of "Rondo"

Part list: 1x ATtiny12 SOIC 20x red LED 1206 5x 47 ohm 0805 1x 10k 0805 2x 100n 0805