Last week on hack-a-day I saw their post on an LED Menorah that was powered by a 9v battery with the lights controlled by dip switches. I thought to myself, “gee, that’s not a very creative design”. There was redemption in the minimalist designs linked too showing a menorah soldered to a tiny2313 and one soldered to an LM2913, both without a circuit board.
These free formed designs were creative but a little too down and dirty for me. I thought I could do better, and immediately thought of the handful of tiny13 8-pin microprocessors I had sitting around. I wanted to make a menorah with the following features in mind:
- Controlled by an AVR ATtiny13
- Powered by ~3v (unregulated to save on parts)
- One button operation
- Sleep mode when the menorah “burns out” after an hour or so
I’m happy to say I did accomplish all of my goals. More after the break.
For more pictures check out my Instructable of this project:
- Power supply that puts out between 2.7v and 3.3v.
- 9 LEDs (I used white)
- 4 resistors (22ohm)
- 1 momentary push button
- 1 pin header (2 pins)
- 1 DIP socket (8 pins)
- 1 AVR ATtiny13 microcontroller
- 1 Circuit board of some type
Here is the full board layout from Eagle CAD. You can see that I have managed just one place where I need to jump over a some traces (in red). I could have avoided this by running a track in between the two pads of LED9 but I avoided this to make etching the board easier.