Arduino Quadruped Spider Robot

A four-legged spider robot powered by an Arduino Nano. This project utilizes a PCA9685 servo driver to control 8 servo motors, enabling a variety of movements that can be controlled via Bluetooth using a smartphone.

Demo

Here are some images, GIFs, and videos of the spider robot in action:

Video Demo:

Click the image above to watch the full demonstration video on YouTube.

Example:

Caption: The spider robot in its default idle position.

Example GIF:

Caption: The spider is happy.

Features

• Bluetooth Control: Wirelessly control the robot using the Dabble app on a smartphone.
• Dynamic Movements: Capable of walking forward and turning left or right.
• Special Actions: Pre-programmed actions like a "happy dance," "defense mode," and a "pull-up" motion.
• Scalable Design: The PCA9685 driver supports up to 16 channels, leaving room for future expansion.

Hardware Components

Component	Quantity	Purpose
Arduino Nano	1	Main microcontroller for processing commands.
PCA9685 Servo Driver	1	Manages PWM signals for all 8 servo motors.
JDY-33 Bluetooth Module	1	Enables wireless communication (SPP & BLE).
Servo Motors	8	Actuators for hip and knee joints.
liPo Battery	2	3.7V LiPo Battery.
3D Printed	*	3D printed for the spider.

Wiring Diagram

Controller and Bluetooth

JDY-33 Pin	Connects to
TX	Arduino Nano D4
RX	Arduino Nano D5
VCC	3.3V or 5V
GND	GND

Servo Driver

PCA9685 Pin	Connects to
VCC	Arduino Nano 5V
GND	GND
SDA	Arduino Nano A4
SCL	Arduino Nano A5
V+	External 5V Power Supply

Servo Motor Connections (to PCA9685)

Channel	Joint	Channel	Joint
0	Front Left Hip	4	Back Left Hip
1	Front Left Knee	5	Back Left Knee
2	Front Right Hip	6	Back Right Hip
3	Front Right Knee	7	Back Right Knee

Software and Dependencies

This project relies on the Arduino IDE and several libraries.

1. Arduino IDE: Download here
2. Required Libraries:
   • Wire (Built-in)
   • SoftwareSerial (Built-in)
   • Adafruit PWM Servo Driver Library
   • Dabble Library

Setup and Installation

1. Assemble Hardware: Connect all components as shown in the wiring diagram. Ensure the external power supply for the servos is correctly connected.

2. Install Libraries: Open the Arduino IDE and install the required libraries via the Library Manager.

3. Upload Code: Flash the main control code to your Arduino Nano.

   spider-robot/main/main.ino

4. Install Dabble App: Install the Dabble application on your smartphone.

5. Pair Bluetooth: Power on the robot and pair your smartphone with the JDY-33 Bluetooth module.

6. Connect in App: Open the Dabble app, connect to the robot, and select the Gamepad module.

How to Use

1. Power On: Turn on the robot. It will assume its default idle position.
2. Connect: Launch the Dabble app and establish a connection with the robot.
3. Control: Use the gamepad interface to control the robot's movements and actions.

Control Scheme

Dabble Input	Robot Action	Function Called
Up Arrow	Move Forward	moveForward()
Left Arrow	Turn Left	turnLeft()
Right Arrow	Turn Right	turnRight()
Triangle	Happy Dance	happyAction()
Cross	Defense Mode	defenseAction()
Circle	Pull-up	pullUpAction()
(No Input)	Idle Position	idle()

Calibration and Debugging

If the robot's movements are erratic, you may need to calibrate the servos.

1. Upload Debug Sketch: Flash the debug/debug.ino file to the Arduino Nano.
2. Open Serial Monitor: Set the baud rate to 9600.
3. Send Commands: Test each servo individually by sending commands in the format <servo_number> <angle>.
   • Example: 1 90 sets servo 1 to a 90-degree angle.
   • Use command 8 to reset all servos to the idle position (45°).

Servo Mappings for Debugging

Servo Number	Joint Assignment
0	FRONT_LEFT_HIP
1	FRONT_LEFT_KNEE
2	FRONT_RIGHT_HIP
3	FRONT_RIGHT_KNEE
4	BACK_LEFT_HIP
5	BACK_LEFT_KNEE
6	BACK_RIGHT_HIP
7	BACK_RIGHT_KNEE

Contributing

Contributions are welcome! If you have ideas for improvements or have found a bug, please feel free to:

1. Fork the repository.
2. Create a new branch (git checkout -b feature/your-feature-name).
3. Commit your changes (git commit -m 'Add some feature').
4. Push to the branch (git push origin feature/your-feature-name).
5. Open a Pull Request.

Alternatively, you can open an issue with the "bug" or "enhancement" tag.

License

This project is open-source. See the LICENSE file for more details.

Acknowledgments

• A big thank you to the creators of the libraries used in this project.
• Inspiration from the broader Arduino and robotics communities.

Contributors

• Tai Ngo: Software Lead
• Vinh Pham: Hardware Lead

Contact

If you have questions or would like to connect:

• Email: vantaingo.056@gmail.com
• LinkedIn: Tai Ngo
• GitHub: TaiVanNgo
• Youtube: taivan130