A Rotary-Dial Pomodoro Timer with Waveshare E-Paper

A Rotary-Dial Pomodoro Timer with Waveshare E-Paper. The published build describes its mechanical design, controls and pin mapping.

PineMux Editorial 30 Sep 2026 2 min read

Microcontrollers & Input

01 / Project overview

Rukenshia’s focus timer pairs a rotary dial with an e-paper display to create a dedicated desk timer. The published build describes its mechanical design, controls and pin mapping. It is a useful example of choosing a display resolution and an input method together, rather than trying to fit a timer onto an arbitrary screen.

02 / Materials & software

ESP32
Waveshare 4.26-inch 800 × 480 e-paper HAT
KY-040 encoder
status LED
printed enclosure

FROM THE ORIGINAL PROJECT
The author’s CAD view of the LED shroud helps explain the light-control part of the enclosure.
Rukenshia/pomodoro · View original image

03 / Compatibility & setup notes

The author explicitly says the repository is not ready to use as-is because some fonts and assets were removed. Allow time to supply alternatives; this is an adaptation project.

04 / Build the project

Review the parts list and the encoder/display pin map.
Get the display and encoder working separately before connecting the complete interface.
Generate or replace the required assets, build the firmware and test the timer before fitting the printed case.

FROM THE ORIGINAL PROJECT
The original preset-selection screen shows how the rotary control is used.
Rukenshia/pomodoro · View original image

05 / Check the result

Test clockwise and counterclockwise movement, button presses, pause/resume and timer completion. Check that quick dial movements do not skip unexpectedly.

PineMux build note: Keep a record of the board revision, firmware version and first successful test. Follow the upstream guide for exact pins and commands.