Fairy Lights

A set of miniature fairy lights for a very small Christmas tree controlled by an ATtiny2313 microcontroller.

Download the schematic and source code

I purchased a very small Christmas tree from my local supermarket as I thought it would be a fun project to try to assemble a miniature set of fairy lights for it. The final product works quite well, and has the following specifications:

• 32 warm white LEDs arranged in four individually-controllable strings of eight LEDs each.
• Five different animated effects that can be cycled through by pressing a button.
• Holding the button switches to the "random" mode which switches to a different randomly-selected effect every so often.
• Holding the button again switches to the "static" mode that allows you to keep all of the LEDs switched on at one of eight different brightness levels.

For more details please see the schematic and source code in the package linked above.

Video demonstration

Additional images

The circuit board that is used to drive the LEDs.

The Christmas tree in all its glory.

The prototype for the Dickson charge pump used to boost the voltage to drive eight white LEDs in series was based around an ATtiny13 rather than the ATtiny2313 used in the final design.

A cardboard jig made soldering all of the LEDs together much easier.