A Low-Cost IMU-based System for Real-Time Barbell Repetition Counting

Not using a program to manage the number of exercise repetitions is usually inexact, leads to inconsistency and breaks focus during exercise at home. This paper introduces a technology that can automatically record and count movements during physical exercises, in real time. An ESP32 microcontroller works with an MPU6050 IMU to analyze data collected from the accelerometer and gyroscope to identify valid repetitions by comparing them to a specific threshold through the usage of a finite state machine. The core advantage comes from developing a three-state algorithm that uses time delays, dead zones and re-trying to avoid getting false results. It is simple to use, inexpensive and it works without external links or wearable corrections. It consistently detects reps quickly, allows setting a target number of reps with serial communication and provides detailed feedback along the way. These experiments have demonstrated that the wearable sensor accurately detects motions in the gym, responds fast in real time and shows minimal errors with a 50 ms sampling rate. Since many people work out on their own, the system is very useful in keeping track of progress and encouraging them.