This is a little fun project that i did to teach students about standalone arduino and product design from the perspective of a embedded developer, explain the concepts of how a perticular compoent is selected and how PCBs are designed and how to manage BoM and deal with board house
The pendent has Attiny 13 at its heart. There are two LEDs which can be programed to generate diferent patterns, there is a latch implemented to turn on and turn off the device using a single switch. The IC that impelents latch also has schmitt trigger configuration to avoid switch debounce. The device works on a coin cell CR1224.
Concept, design, prototyping and firmware by Deepankar Maithani