If you want to mess around with some microcontrollers but don’t really have a purpose in mind this project is perfect for you. It’s cheap, easy to assemble, and there’s blinking LEDs! [TigerUp] shows us how he put together some LED matrix pendants using just five components.
He calls the project Tiny Matrix, which is fitting as the pendant outline is barely 0.5″ by 0.7″. On the back an ATtiny2313 chip has been soldered directly to the legs of the LED display. They just happen to line up with I/O pins on the chip which makes for super simple soldering. Power comes from a coin-cell which is connected to the pendant by a red and black wire which make up the necklace for the device. The last two components not yet mentioned are a momentary push switch for changing modes, and a pull-up resistor on the reset pin. The bill of materials rings in at $4 and his firmware offers up nine different modes as you can see in the clip after the break.
[TigerUp] was inspired by this 8×8 matrix project.