Python SDK - StarArm 102 Robotic Arm Control

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📖 Introduction

The Python SDK is the Python control interface for the StarArm 102 robotic arm. It provides an easy-to-use Python API for real-time robotic arm control. The SDK supports Leader/Follower teleoperation mode and can directly control the robotic arm servo through UART serial port.

✨ Core Features

• 🤖 Leader/Follower teleoperation: supports real-time control of the Follower robotic arm by the Leader robotic arm
• ⚡ High real-time performance: supports a control frequency of 100 Hz+
• 🎯 Multi-joint control: controls 7 servo joints at the same time
• 📊 Performance monitoring: displays the control frequency in real time
• 🔧 Easy to use: Python-based and requires no complex configuration

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🚀 Quick Start

Environment Requirements

Item	Requirement
Operating system	Ubuntu 22.04
Python version	Python 3.8+
Hardware device	StarArm 102 robotic arm (Leader + Follower)
serial port device	Two USB-to-serial port devices

Install Dependencies

# 安装 Python 依赖包
pip install pyserial fashionstar-uart-sdk

Hardware Connection

1. Connect the Leader robotic arm:
2. Connect the Leader robotic arm to the computer with a USB cable.

3. Confirm the port number (default: /dev/ttyUSB0).

4. Connect the Follower robotic arm:

5. Connect the Follower robotic arm to the computer with a USB cable.

6. Confirm the port number (default: /dev/ttyUSB1).

7. Check USB devices:

# 查看所有串口设备
ls -l /dev/ttyUSB*

# 如果没有权限，赋予读写权限
sudo chmod 777 /dev/ttyUSB*

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📂 Project Structure

Python_SDK/
├── stararm102_ro.py       # 主从控制程序
└── README.md              # 本文档

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💻 Usage

Basic Usage

1. Configure Serial Port Parameters

Edit the stararm102_ro.py file and modify the following parameters:

SERVO_BAUDRATE = 1000000          # 舵机通信波特率
LEADER_PORT_NAME = "/dev/ttyUSB0" # Leader 机械臂端口号
FOLLOWER_PORT_NAME = "/dev/ttyUSB1" # Follower 机械臂端口号

2. Run the Leader/Follower Control Program

# 赋予 USB 设备权限
sudo chmod 777 /dev/ttyUSB*

# 运行控制程序
python3 stararm102_ro.py

3. Program Functions

After startup, the program performs the following operations:

1. Initialize serial port connections:
2. Establish the UART connection for the Leader robotic arm.

3. Establish the UART connection for the Follower robotic arm.

4. Read Leader status:

5. Read the joint angles of the Leader robotic arm in real time.

6. Supports 7 servo units (ID: 0-6).

7. Control Follower motion:

8. Convert Leader joint angles into Follower control commands.

9. Send commands through multi-turn angle interval control.

10. Performance monitoring:

11. Display the current running frequency (Hz) every second.
12. The control frequency is usually around 200 Hz.

4. Stop the Program

Press Ctrl+C to terminate the program.

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🔧 API Description

Main Function

main(args=None)

Main control function

Function:

• Initialize Leader and Follower serial port connections.
• Read Leader joint angles in real time.
• Control the Follower to follow the Leader.
• Display the running frequency.

Parameters: none

Servo Control Parameters

Parameter	Value	Description
SERVO_BAUDRATE	1000000	servo communication baud rate
LEADER_PORT_NAME	/dev/ttyUSB0	Leader port number
FOLLOWER_PORT_NAME	/dev/ttyUSB1	Follower port number
servo_ids	[0,1,2,3,4,5,6]	servo ID list

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📊 Control Flow

┌─────────────┐
│  Leader     │
│  机械臂      │
└──────┬──────┘
       │ 读取角度
       ▼
┌──────────────────┐
│   UART 串口通信   │
│ (/dev/ttyUSB0)   │
└──────┬───────────┘
       │
       ▼
┌──────────────────┐
│  Python 控制程序  │
│  - 数据处理       │
│  - 角度转换       │
└──────┬───────────┘
       │ 发送指令
       ▼
┌──────────────────┐
│   UART 串口通信   │
│ (/dev/ttyUSB1)   │
└──────┬───────────┘
       │
       ▼
┌─────────────┐
│  Follower   │
│  机械臂      │
└─────────────┘

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🛡️ Safety Notes

1. Pre-operation check:
2. Make sure the USB connection is stable.
3. Confirm that there are no obstacles around the robotic arm.

4. Check that the power supply is normal.

5. Emergency stop control:

6. Press Ctrl+C to stop the program immediately.

7. If an exception occurs, unplug the USB cable to disconnect it.

8. Joint limits:

9. Make sure the Leader robotic arm is operated within a safe angle range.

10. Avoid fast, large-range movements.

11. Power management:

12. Use a stable 12 V power supply.
13. Avoid voltage fluctuations.

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🐛 Troubleshooting

Common Issues

Q1: Cannot find the /dev/ttyUSB0 device?

# 检查 USB 设备
ls -l /dev/ttyUSB*

# 检查 USB 设备信息
lsusb

# 查看串口日志
sudo dmesg | grep ttyUSB

# 如果被 brltty 占用，卸载它
sudo apt remove brltty

# 赋予权限
sudo chmod 777 /dev/ttyUSB*

Q2: serial port connection failed?

• Check whether the USB cable is loose.
• Confirm that the port number is correct.
• Try another USB port.
• Check whether the driver is installed correctly.

Q3: Control frequency is too low?

• Check whether serial port communication is normal.
• Reduce the load from other running programs.
• Use a USB 3.0 port to improve speed.

Q4: The Follower robotic arm does not follow the Leader?

• Check the Follower port-number configuration.
• Confirm that the servo IDs are set correctly.
• Check the serial port communication baud rate.

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📖 Detailed Documentation

• Project Overview - project overview
• ROS2 HUMBLE Documentation - ROS2 control method
• LeRobot Documentation - LeRobot framework integration

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🔗 Related Links

• FashionStar UART SDK
• FashionStar Website

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📄 License

This project is open source under the MIT License.

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👥 Acknowledgements

• Thanks to: FashionStar Technology for providing hardware support and the SDK.

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Enjoy using it. If you have questions, feel free to submit an Issue.