ATMegaZero ESP32- S2, showing optional color-coded 40 ... it has some neat features like a connector for inexpensive SSD1306 and SH1106-based OLED displays. Being able to use existing accessories ...

The Pomdoro technique of time management has moved on a little from the tomato-shaped kitchen timer which gave it a name, as [Rukenshia] shows us with this nifty ESP32 and e-paper design.