Scalable Multi-Servo Control

A multi-modal system for controlling large arrays of hobby servos in 2-DOF (Degrees of Freedom) configurations using TouchDesigner and an ESP32 microcontroller.

This repository contains the project files for a scaleable framework designed to serve as the foundation for complex kinetic art installations, enabling the precise, choreographed movement of many individual 2-axis mechanisms.

Features

• 2-DOF Mechanism Control: The entire system, from the C++ code to the TouchDesigner network, is architected to control servos in X/Y pairs, creating 2-DOF movement.
• Multi-Modal Control: The system can be controlled via three distinct input methods within TouchDesigner:
  • Real-time Gesture Control: Using a Leap Motion sensor for direct, intuitive manipulation.
  • Manual Slider Control: A simple UI for direct control over the X and Y axes of all servos.
  • Pre-Programmed Automation: Using TouchDesigner's Animation COMP for precise, repeatable keyframe sequences.
    • (Update coming soon. See https://github.com/steven-tbd/robotic-arm-control-system for example of using Animation Comp to control servo movements)
• Wireless-Capable & Robust Communication: Utilizes an ESP32 to receive control data via OSC over UDP, a professional and flexible protocol for interactive installations.
• Scalable Architecture: Employs a PCA9685 driver board to control large arrays of servos (12 servos / 6 2-DOF mechanisms in the prototype).

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I/O Diagram

INPUT:  [Leap Motion Camera (Sensor)] ---> (USB HID) ---> [Computer/TouchDesigner (Processor/VPL)]
OUTPUT: [Computer/TouchDesigner (Processor/VPL)] ---> (WiFi/Network UDP) ---> [ESP32/C++ (Microcontroller Board/Arduino IDE)] ---> (I2C) ---> [PCA9685 (Motor Control Board)] ---> (PWM) ---> [12x Hobby Servos (Actuator)]

• This workflow can switch between inputs from TouchDesigner: Leap Motion camera, manual, and pre-defined movement.
• Motor movements are created using the Animation Comp in TouchDesigner.
• For installations, the networked protocol connection should be switched to a tethered Serial link for reliability.

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Repository Contents

• ESP32:
  • touchdesigner-udp-com.ino: The C++ code for the ESP32. It connects to WiFi, listens for incoming OSC messages, and controls the X/Y servo pairs.
• TouchDesigner:
  • motor-control-system_005v2-1.toe: The multi-modal control network with switchable inputs for Leap Motion, Manual sliders, Programmed Movements, and a Reset position.

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Setup & Usage

Hardware Requirements

• ESP32 Development Board
• PCA9685 16-Channel Servo Driver
• EMAX ES08MA II Servos (or similar hobby servos)
• Leap Motion Controller
• External 5V power supply for the servos

Software Requirements

• TouchDesigner
• Arduino IDE with the ESP32 board manager installed.
• Required Arduino Libraries: Adafruit_PWMServoDriver, OSC

Instructions

1. Configure WiFi: Open touchdesigner-udp-com.ino and replace the placeholder ssid and password with your WiFi credentials.
2. Upload Code: Upload the sketch to your ESP32 board.
3. Run TouchDesigner: Open motor-control-system_005v2-1.toe. The network is configured to send OSC data to the ESP32's IP address (update the IP address in the OSC Out CHOP).
4. Interact: Use the buttons at the top of the Touchdesigner network switch between inputs running through the switch_inputMaster Chop to the OSC Out chop.

Note: Python Script for Keyframe Generation

The motor-control-system_005v2-1.toe file contains a Python script (generate_keys_script) designed to automate the creation of keyframe animations.

This script provides a fast, data-driven way to create and modify complex choreographies. Instead of manually editing curves in the Animation Editor, you can simply define servo "poses" in a table (null_table_keys), and the script will automatically generate the correctly formatted keys table to drive the Animation COMP.

Project Links & Demos

• Project Write-up: https://stevenmbenton.com/project/scalable-multi-servo-control/
• YouTube Demo: Gesture-Controlled 2-axis mechanisms