---
title: "Workout Timer with a phone remote"
description: "A round timer for workouts with sound cues and a built-in web server, so it can be started from a phone."
date: 2023-03-04T18:09:29+01:00
lastmod: 2026-10-16T18:58:52+02:00
url: https://klimek.link/projects/workout-timer/
author: "Marcin Klimek"
source: https://klimek.link/projects/workout-timer/
---

# Workout Timer with a phone remote

I wrote this interval timer for round-based training, the way a boxing round timer works, as a **.NET 7 Windows Forms** app where you set the work time, the rest time and the number of rounds.

Under the interface I put a small timer engine that raises events on every tick, at half-time, in the last ten seconds, at the start of rest, on the next round, on the last round and at the finish. For every one of those the app plays a sound (a gong, beeps, a count of short beeps for the round number, and chimes at the end). All of the sounds are synthesized by a small script in the repository, so the project is free to share under the GPL.

The app also starts an embedded HTTP server on port 8080 that serves a small web page and has JSON `start` and `stop` endpoints, which lets you control the timer from a phone's browser while you're on the mat.

*Diagram: How the timer engine, sounds and the phone control fit together* There's an early experiment with a cross-platform .NET MAUI version as well.

[Source on GitHub](https://github.com/marcinklimek/workoutTimer).

Source: https://klimek.link/projects/workout-timer/