I had to build a blinking device as a Proof of Value (PoV).<br><br>The concept is quite simple:<br>* The device should blink in green during 2 hours,<br>* After two hours, the device should blink in red,<br>* After two more hours, the device should stop blinking,<br>* The time counter can be reset with a magnet near the device.<br>* The device had to be as small as possible, as it should be wear and visible.<br><br>I chose the components, made the PCB layout, write the code, and built the case with my 3D printer.<br><br>You can read the full blog post and get the source code here:<br><a target="_blank" rel="noopener noreferrer" href="https://www.iot-experiments.com/blinking-wearable/">https://www.iot-experiments.com/blinking-wearable/</a>