Inspired by various LED Throwies, blinking LEDs and similar instructables I wanted to do my version of an LED controlled by a microcontroller.
The idea is to make the LED blinking sequence reprogrammable. This reprogramming can be done with light and shadow, e.g. you could use your flashlight.
How is it done?
It consists of an LDR, an LED and a tiny microcontroller. I used a ATtiny13v which is able to run with 1.8V. That makes it easy to power it with smallest batteries or even fruits.
All components can be easily used on a breadboard. Be aware, that you will need a separate programmer or an ISP adapter to program it.
The final version
The final version is powered by a CR2032 cell. It should have enough power for at least two weeks, depending on the light sequence it plays.
I have done a step-by-step instructable here.
Here are some responses to the instructable