Rock Paper Scissors Shock

Inspiration

We've all played Rock Paper Scissors to settle something — who pays, who goes first, who does the dishes. It's the world's most universal tiebreaker. But we always felt like it was missing something.

Stakes.

Verill pitched it first: "What if the loser got shocked?" The rest of us agreed before he even finished the sentence. The kind of idea that's so stupid it loops back around to genius.

A few hours later we had flex sensors stitched onto gloves, an ESP32 taped to the back of a hand, a 3D printer running in the corner, and a very real debate about who was going to be the first test subject.

Rock Paper Scissors Shock was never meant to be practical. It was meant to be fun, a little dangerous, and very, very silly.

What it does

Two players each wear a smart glove. On countdown, both throw their gesture — Rock, Paper, or Scissors. The gloves detect the gesture, send it wirelessly to a central server, and the server decides the winner. The loser gets shocked. Ties result in nothing — just like in real life.

How we built it

Gloves — flex sensors stitched onto each glove on the index and ring fingers, wired to an ESP32 microcontroller taped to the back of the hand, powered by a LiPo battery
Gesture detection — two flex sensors per glove read ADC values. Finger position combinations map to Rock, Paper, or Scissors
Wireless communication — each ESP32 connects over WiFi to a central server, sending the detected gesture on countdown completion
Server — compares both gestures, determines the loser, and sends a shock trigger back to the losing glove
Shock mechanism — the losing glove's relay triggers the shock output
UI — a web interface displays the countdown, gestures, and winner in real time

Challenges we ran into

Hardware is humbling. We spent a significant chunk of the day debugging flex sensor calibration — getting consistent ADC readings that reliably map to Rock, Paper, and Scissors took way more iterations than expected. The servo motor connection also gave us grief right at the end, including a last-minute reprint of the motor stick because the tolerances were just slightly off. Cable management on a wearable is also a completely different problem from a breadboard — zip ties and electric tape became our best friends.

Accomplishments we're proud of

We built a fully functional wearable gesture-detection system in 8 hours from scratch — flex sensors stitched onto gloves, ESP32s talking wirelessly to a central server, and a web UI that shows the countdown and result in real time. The gesture detection is reliable, the server logic works, and both gloves connect seamlessly. Oh, and we 3D printed components live at the hackathon.

What we learned

Wearable hardware is a completely different beast from a normal project. Tolerances matter, cable management is an art form, and soldering on a deadline is a special kind of stress. We also learned to cut scope ruthlessly — knowing what to drop and when is just as important as knowing what to build.