We love the design of this calculated doom clock, and it’s quite simple inside — an Arduino Pro Mini outputs the graph on an 2.9″ e-paper display, and both are powered with a 5.5 V solar panel.

Learn how to create a simple heart rate monitor using an Arduino Pro Mini, PulseSensor, and OLED display. This beginner-friendly project is perfect for learning basic electronics, sensors, and ...

The creator of the Arduino RF Pro Mini open source development board Etienne, explains a little more about the inspiration behind the project. “ I’ve loved Arduino for years.