What is it?

The Shamrock is a PCB-Celtic knot shaped like a shamrock with 20 LEDs. It is an SMD soldering kit. The LEDs are independently controlled by an ATTINY 13 using charlieplexing. Code is uploaded to the device with AVR dude using a Bus Pirate, a AVRisp mk II or similar. It is not Arduino compatible. It comes pre-programmed in the kit.

It is also possible to embed plastic into the holes in the PCB using this method: https://www.youtube.com/watch?v=kOk-2FF_amk . Plastic is not included in the kit. Melting plastic into the PCB is done at your own risk.

Materials

• 5 110 Ohm resistors
• 1 0.1 uF capacitor
• 20 LEDs
• 1 ATtiny13A
• 3 to 5v power source (USB, batteries, etc.)

Directions

1. Solder on all 20 LEDS paying attention to the LED orientation on the silkscreen.
2. Solder the capacitor onto the PCB.
3. Solder the ATtiny13A onto the PCB.
4. Solder the Resistors onto the PCB.
5. Solder the power cable onto the PCB.
6. (Optional) Chain them together by soldering cables onto eachother.

Why did you make it?

I designed these as a St. Patrick's Day decoration.

What makes it special?

By 3D printing a coin cell holder, you can turn this into a necklace (http://hammeshacks.com/coinclasp/).