Tennis Buddee

Tennis Buddee is a smart tennis racket that helps players understand their own shots and explore how a change might affect their game. Tennis lessons can be expensive, and most recreational players have little information about what happens during the hundreds of shots they hit between lessons. I wanted to make that information accessible during ordinary play, using the racket they already own. I built a sensor insert that fits inside the racket handle. It combines an LSM6DSV320X motion sensor, a microphone, and an ESP32-C3. The racket detects impacts and computes shot measurements on the device, including swing speed, ball speed, spin, stroke type, and estimated contact location. A small machine-learning model I trained uses the sound of impact to estimate where the ball met the strings. Players can also double-tap the handle to keep score during a match. The experience continues on iPhone, Mac, Apple Watch, and Meta Ray-Ban Display. Players can see their shots, track sessions and scores, and play with friends. The glasses show information such as the latest shot, score, and drill progress while the player stays on court. Meta Muse Spark turns that data into an interactive way to explore a player's game. Rather than relying on generic answers, Muse can call tools to inspect the player's shots, compare sessions, read live racket data, and run a physics simulation. In “What If,” a player can ask what might happen if they changed their swing or contact point. Muse uses the player's own data and the simulator to predict the result, then can suggest a drill to try on the watch or glasses. “Scout Yourself” examines patterns in a player's game and describes how an opponent might exploit them. I tested the racket in an 86-minute club session and used what I learned to improve the design. For example, unreliable Bluetooth streaming led me to move shot processing onto the racket and add storage for shots captured while disconnected. The app is also available to test online at tennisbuddy.net/emulator with a data derived from pro tennis players match videos, so you get the full Tennis Buddee experience and feel like a pro. Tennis Buddee brings sensing, on-device processing, Meta AI, and wearable displays together in one seamless experience: hit a shot, understand it, explore a change, and take that idea back onto the court.