This is a focus timer device I built for a friend. All the relevant source code and a more detailed writeup of the project can be found on the GitHub repository: [https://github.com/Rukenshia/pomodoro](https://github.com/Rukenshia/pomodoro)

Parts

• ESP32 (I used an AZDelivery ESP32 NodeMCU)
• WaveShare 4.26inch e-Paper display HAT, 800x480 (link)
• KY-040 rotary encoder with button
• A single WS2812 LED (could be replaced with a simple RGB LED)A
• A USB-C connector (like this one)
• 3d printed case (onshape file), download here as well
• Some resistors and 0.1uF capacitors
• The bottom part of the case is printed with fuzzy skin, which makes it take longer - feel free to disable

Print Recommendations

• The case is printed using fuzzy skin - to save time you can disable this
• The top part of the display frame is very thin and flimsy, I recommend turning the fans settings lower as needed
• The USB-C slot is a press fit, you might need to slightly adjust the sizes
• Print the LED Shroud in a white, solid filament
• I preferred the matte black PLA for the case, but PLA-CF could also look great