RobotArmMK1.2

🤖 Desktop Robot Arm

A compact, fully customizable desktop robot arm designed for small-scale automation tasks. Developed as part of a Bachelor of Engineering in Mechatronics at Technological University Dublin, this project integrates 3D-printed components, servo motor actuation, custom electronics, Arduino-based firmware, Bluetooth control, and an Android app interface.

Figure: CAD render of the assembled Desktop Robot Arm

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📦 Features

• 6 Degrees of Freedom using MG66R and SG90 servo motors
• Bluetooth-enabled control with HC-05 and MIT App Inventor
• Android app with presets and direct manual controls
• Custom PCB with schematics and Gerber files (KiCAD)
• Modular 3D-printed design with STL files included
• Smooth servo motion using filtering algorithms

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📁 Repository Structure

1. Documentation

   • RobotArm-ProjectReport.pdf – Full project report with design, testing, and results

2. Electrical

   • KiCAD-PCB/ – Circuit schematics, custom PCB layout, and Gerber files

3. Mechanical

   • STL-Files/ – 3D-printable mechanical components
   • Includes exploded views and CAD drawings

4. Software

   • Arduino-Firmware/ – Code for ATmega328P (Arduino)
   • MIT-App-Inventor/ – Android app .aia source and .apk installer

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🔧 Hardware Overview

• Microcontroller: ATmega328P (Arduino Uno or custom board)
• Servos: 5× MG66R, 1× SG90
• Peak Current Draw: 2.8A (measured)
• Bluetooth Module: HC-05
• Build Volume: 135mm x 90mm footprint
• Chassis: Fully 3D-printed components (PLA)

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📱 Android App

• Built with MIT App Inventor
• Control individual servo angles or trigger gesture presets:
  • Home, Ready, Wave, Screwdriver, Circles, Diagonals, Worm, Demo
• Bluetooth communication with Arduino via HC-05

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📐 Mechanical Design

• All STL files for 3D printing included
• Exploded views, BOM, and design drawings available
• Desktop-sized and modular for easy assembly and customization

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🔌 Electrical Design

• Custom PCB designed in KiCAD
• Includes:
  • Circuit schematics
  • PCB layout
  • Gerber files for fabrication
• Power and signal headers for servos, Bluetooth, and logic

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🧠 Arduino Firmware Features

• Servo smoothing for fluid movement
• Bluetooth and Serial input parsing
• Support for:
  • Comma-delimited angle commands (e.g., 90,90,90,90,90,90*)
  • Keyword triggers (Demo, Home, etc.)
  • Real-time smoothing level adjustment (0#/100#)

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🚀 Getting Started

🔩 Requirements

• Arduino IDE
• Android device with Bluetooth
• 3D printer (recommended material: PLA)
• 5V power supply (min. 3A)
• HC-05 Bluetooth module
• Basic tools for assembly and soldering

🛠️ Setup Instructions

1. 3D Print all components from the STL-Files/ folder.
2. Assemble using provided CAD diagrams.
3. Upload firmware from Arduino-Firmware/ to your ATmega328P.
4. Install Android app from MIT-App-Inventor/ (.apk) or open .aia to modify.
5. Pair Bluetooth module and connect via the app.
6. Power on the system and start experimenting!

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📚 Documentation

📄 Full design details, diagrams, testing results, and methodology can be found in the Project Report (PDF).

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🧩 Future Improvements

• Add tactile or force sensors
• Integrate IoT control (Wi-Fi, MQTT)
• Implement gesture learning via AI
• Design swappable gripper attachments
• Develop an educational kit version

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📝 License

This project is open-source and distributed under the terms of the GNU General Public License v3.0 (GPL-3.0).

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👤 Author

Ethan Lawlor
B.Eng. Mechatronics
Technological University Dublin