Attention Clock: A Physical Pomodoro Timer

Background

Knowledge is free — but you need to pay attention.

Nowadays, however, it is becoming harder and harder to stay focused. Phones, notifications, and endless distractions constantly compete for our attention.

At the beginning of 2026, I made a resolution to take back control of my focus.

Back in 2023, I had already built a tomato clock using a Particle P2. The idea was simple: press a button to start a focus session. But in reality, I often forgot to press the button, and after a few weeks I completely lost interest in using the tomato clock to track my work.

This time, I wanted to improve the design by adding a more meaningful feature: IoT connectivity.

With this new version, the device can record how many times I use it and send me a daily summary email. By adding this feature, the tomato clock becomes more motivating, because I can clearly see how much focused work I have completed each day.

Hopefully, this will help me build a stronger habit of concentration.

How It Works

For this version, my goal was to keep the system as simple as possible.

All I need to do is press a button when I want to start tracking a focus session. Everything else happens automatically.

The workflow looks like this:

• The Particle P2 stays connected to the Particle Cloud.
• When the button is pressed, the device starts a 30-minute progress bar.
• At the same time, the P2 publishes an event to the Particle Cloud.
• Particle Tachyon listens for these events and stores them in a local database.
• Every day, Tachyon runs a scheduled task that sends me an email summary showing how many tomato sessions I completed during the week.

The email looks something like this:

🍅 Tomato Clock Weekly Report

Total sessions: 66
Focus time: 1980 minutes

Daily breakdown (Mon → Sun):

Mon | ████                 8
Tue | ███████              14
Wed | ███████████          23
Thu | ███████████████      31
Fri | ██                   4
Sat |                      0
Sun |                      0

Summary

As mentioned above, this new version of the tomato clock has been much more encouraging for me.

By simply checking the email summary every day, I can clearly see whether I am improving my focus or not. Seeing the number of completed sessions gradually increase gives me a small sense of progress and motivation.

In a world full of distractions, this simple device helps me build a daily habit of focused work.