photo CC BY-SA 2.5, GFDL or CC-BY-SA-3.0, Erato at Italian Wikinews, via Wikimedia Commons

I know many people who get value from a simple tool called the Pomodoro Technique.

It's a time management technique used to break work into periods of activity separated by short breaks. Each activity period is called a pomodoro. Why "pomodoro"? The technique was developed by Francesco Cirillo, who named the technique "pomodoro" as a nod to the tomato kitchen timer he initially used.

The technique has come a long way from those humble beginnings with phone apps, web versions, etc. I decided to make a simple hardware version in CircuitPython with a rotary encoder to set the time and mode!


Here's what you'll need from Adafruit to build the Pomodoro Timer:

1 x Adafruit ItsyBitsy M0 Express - for CircuitPython and Arduino IDE
What's smaller than a Feather but larger than a Trinket? It's an Adafruit ItsyBitsy M0 Express!
1 x NeoPixel Ring - 16 x 5050 RGB LED with Integrated Drivers
Round and round and round they go! 16 ultra bright smart LED NeoPixels are arranged in a circle with 1.75" (44.5mm) outer diameter.
1 x Piezo Buzzer
Piezo buzzers are used for making beeps, tones and alerts. This one is petite but loud!
1 x Rotary Encoder + Extras
This rotary encoder is the best of the best, its a high quality 24-pulse encoder, with detents and a nice feel.
1 x LiIon/LiPoly Backpack
Adafruit LiIon/LiPoly Backpack Add-On for Pro Trinket/ItsyBitsy
1 x Breadboard-friendly SPDT Slide Switch
These nice switches are perfect for use with breadboard and perfboard projects.
1 x Lithium Ion Polymer Battery - 3.7v 500mAh
Lithium ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light and powerful. This battery has a capacity of 500mAh for a total of about 1.9 Wh.
1 x Silicone Cover Stranded-Core Wire - 50ft 30AWG Blue
Silicone-sheathing wire is super-flexible and soft, and its also strong! Available in various colors.

Materials and Supplies

  • 3D Printer and Filament
  • Superglue
  • Small diameter heatshrink tubing


  • Wire Strippers
  • Wire Cutters
  • Pliers
  • Pin-vise drill and 0.8mm drill bit
  • Soldering Iron
  • Solder
This guide was first published on Jul 02, 2018. It was last updated on Jul 02, 2018.
This page (Overview) was last updated on Oct 07, 2020.