ATtiny13A PCB Star Wearable

Description

I've designed this tiny twinkly star for JLCPCB's Christmas decorations design challenge, but I only got to order & assemble it now, so I've repurposed it as a wearable for now.

This was just a fun and quick project, so it's super simple: the LEDs are controlled by an ATtiny13A microcontroller and powered by a 3V CR1225 battery. And it's only 4x4cm wide!

Components

1 × JLCPCB Customized PCB

8 × 0603 2mA Amber LEDs

4 × 0603 5mA White LEDs

4 × 0603 5mA Blue/Purple LEDs

1 × ATTINY13-20MMU Microcontroller Microprocessors, Microcontrollers, DSPs / ARM, RISC-Based Microcontrollers

Build Instructions

Collapse

1

PCB Order & Assembly

I used Figma to create the star shape which I've exported to Eagle CAD using Gordon Williams' SVG to Eagle CAD converter.

I ordered the PCBs from JLCPCB and assembled them myself. I was wondering if they'd be able to cut the PCB at such sharp angles and I'm actually pleased with how they look.

Here's the top of the PCB:

And here's the back:

I've added 4 pads on the back, in case I want to solder some hooks on it to use it as a wearable. The detailed schematic and the Eagle CAD files are here.
2

Programming

I've placed the ISP pads on the back of the star in order to program the ATtiny using this DIY pogo-pins adaptor for my USBasp programmer (3.3V logic).

I've used the MicroCore ATtiny13A core and (very important!) I've disabled the brown-out detection (BOD) when burning the bootloader. If it's set too high the LEDs won't turn on when the battery starts discharging. The code is also on Github.
3

Final product

This is the finished product!