Light patterns with 3 LEDs - a party gag
This was a project for me to learn about the ATTINY13A, one of the most low cost processors. They are small form factor and ideal for a brooch I created. The purpose is that a group of people can 'see' each other in the night in a foreign city, so nobody gets lost.
There are two contacts at 9 and 12 o'clock, if connected briefly with a small cable you may toggle the light-show on and off.
The battery is 3V CR2016 I use different color LEDs all SMD1206 and resistors to adapt for different forward voltage:
- White/Blue: FV 2.8-2.9V 5.6 Ohm
- Red/Yellow: FV 2.0-2.2V 47.0 Ohm
- Green: FV 2.7-2.8V 12.0 Ohm