Introduction

The “Smart Wing Chun Dummy” is an interactive training device that combines traditional martial arts equipment with modern electronics. Designed to improve reflexes, memory, and striking accuracy, the dummy features strain gauges and LEDs embedded in the arms. It plays a version of the “Simon Says” game, where fighters must strike the correct lit arm in a growing pattern, with increasing speed and difficulty over time.

Table of Contents

URS
Physics
Free Body Diagram
Design
BOM
Electronics
Code
Modeling
Fabrication
Guides
Notes
Contact

URS

User Requirement Specifications
A list of requirements that need to be met. Posted to GitHub

Constraints	Approach	Achieved
Size:	Human-sized dummy (approx. 5’6″)
Depth:	20″
Height:	66″
Width:	24″
Weight:	< 50 lbs
Cost:	<$250
Power	USB-C / Battery
Decibels	< 60 dB
Geometry	Cylindrical body, 3 arms
Case	Wooden / PVC casing
Assemble	DIY-friendly, under 2 hrs
Temperture Range	0°C to 40°C

Physics

Physics

• $Strain = ( frac{\Delta L}{L_0} )$
• $Stress = ( \frac{F}{A} )$
• Force detection via strain gauge Wheatstone bridge
• Reaction time = Strike timestamp – LED ON timestamp
• Impact force derived from calibrated strain gauge output

FBD

Free Body Diagram

• Dummy body represented as vertical cylinder
• Arms represented as cantilever beams with load vectors
• Impact force shown as arrows on arm ends
• Reactions: fixed body base, moment on arms

Design

Design

• Cylindrical body with three arms
• Each arm has embedded LED strip and strain gauge
• Electronics housed inside main body
• LED color feedback for correct/incorrect strikes
• Optional base with vibration dampening

BOM

Bill of Materials || BOM

Qty	Name	Cost	Notes
10	Strain Gauge Sensor	$8.50/each	For detecting arm impacts
3	SEZO WS2812B LED Strip Light 3.3FT/1M	$9.99/each	Visual cue per arm
1	ESP32 Dev Board (3)	$15.99	Control unit, Wi-Fi enabled
1	3″ PVC Pipe (4ft)	$14.00	Dummy body
3	PVC Arms or Wood Dowels	$6.00/each	Strike targets
1	Wiring, Breadboard, etc.	$15.00	Prototyping essentials

Electronics

Electronics

Schematics

• Napkin sketch: ESP32 to LED strips and strain gauge bridges
• Logic: LEDs light up → wait for hit → verify via strain change → next step

Wokwi

Sketch a simple simulation showing ESP32 → LED + strain gauge logic

Notes

• May need analog-to-digital converter for gauges
• Ensure debounce logic on hits

Code

Coding

Sequence Diagram

• Start → Light up arm 1 → Wait for strike → Check hit → Light up next + previous → Repeat → Speed increases

Repo

• GitHub repo (TBD): wingchun-simon

Notes

• FastLED or Adafruit Neopixel library for lighting
• Use millis() for time-based pattern timing
• Data logging for force and reaction time

Modeling

Modeling

Parametric Model

• Body + Arm placements
• Internal compartment for electronics

Revisioning

• V1: PVC Frame w/ exposed wires
• V2: Enclosed body with wireless module

Notes

• Add cutout for access to ESP32 USB

Fabrication

Fabrication

• [ ] 1. Cut arms and body sections from PVC or wood
• [ ] 2. Drill and embed LED strips + sensors
• [ ] 3. Mount electronics and connect wiring
• [ ] 4. Upload firmware and test patterns
• [ ] 5. Tune sensitivity and thresholds
• [ ] 6. Add final enclosure or finish

Revisioning

• Add color touch display for control (future rev)

Notes

• Recommend using hot glue or epoxy to secure sensors

Guides

Guides

Assemebly Guide

• Link to Google Doc (TBD)

Operating Guide

• Link to YouTube demo (TBD)

Notes

• Consider printable QR code on dummy to pull up manual

Notes

Notes

• Could expand to torso and leg targets
• Consider gamified app integration
• Add haptics for missed hits?