Tempo: An affordable activity vest for sprinters
Built by Kyle Gordon
The Problem My friends and I started short sprinting at the beginning of the semester. Our routine consists of six sets of 100-meter dashes with a two-minute rest period. We do this in the gym as a way to get cardio in after our strength training sessions. During these workouts, we lack a reliable way to track time, distance, heart rate and speed. While I have an Apple Watch for general workouts, the device lacks a built-in option to track interval sprinting. My friends rely on less accurate methods like manually tracking their times with a stopwatch. Beginners and hobbyists currently have no affordable way to track interval sprinting and the associated health metrics without spending a significant amount of money. The Solution Taking inspiration from how professional soccer players measure their performance, I want to create an affordable, vest-like wearable. The device will track sprinting speed, distance and sprint time using GPS. It will also include a small wrist-based heart rate monitor. All of this data will be sent to a web app for easy viewing. How It Works The main device is a GPS tracker based on an ESP32 chip that processes sensor data. Location Tracking: The GPS uses the NEO-M9N module with a 25Hz update rate for fast sprints. Time Tracking: A real-time clock logs precise time data. Acceleration: An IMU measures sprinting acceleration. Hardware Design: The main unit is a small, removable module for easy recharging, stored in a generic GPS vest while in use. The heart rate wristband uses photoplethysmography, relying on light to detect blood volume changes to measure heart rate. Both modules are powered by lithium-ion batteries and charge using USB-C. Each device stores data using onboard NAND flash memory. The app is based on a Bluetooth web application. It is easier to code and develop while providing benefits similar to a native application. You will be able to start workouts and view data on the web application.