Python SDK - StarArm 102 Robotic Arm Control

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📖 Overview

The Python SDK is the Python control interface for the StarArm 102 robotic arm. It provides a simple and easy-to-use Python API for real-time robotic arm control. This SDK supports leader-follower teleoperation and can directly control the robotic arm servo through the UART serial port interface.

✨ Key Features

• 🤖 Leader-follower teleoperation: Supports real-time control of the Follower arm with the Leader arm.
• ⚡ High real-time performance: Supports 100Hz+ control frequency.
• 🎯 Multi-joint control: Controls 7 servo joints at the same time.
• 📊 Performance monitoring: Displays the control frequency in real time.
• 🔧 Easy to use: Built with Python and requires no complicated setup.

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🚀 Quick Start

System Requirements

Item	Requirement
Operating System	Ubuntu 22.04
Python Version	Python 3.8+
Hardware	StarArm 102 robotic arm (Leader + Follower)
serial port Devices	2 USB-to-serial port adapters

Install Dependencies

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

Hardware Connection

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

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

4. Connect the Follower arm

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

6. Confirm the port name (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 behavior

After startup, the program performs the following operations:

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

3. Establish the UART connection for the Follower arm.

4. Read Leader status

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

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

7. Control Follower motion

8. Convert the Leader joint angles into Follower control commands.

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

10. Performance monitoring

11. Display the current running frequency (Hz) once per second.
12. The control frequency is typically around 200Hz.

4. Stop the program

Press Ctrl+C to stop the program.

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🔧 API Reference

Main Function

main(args=None)

Main control function.

Functions:

• Initialize the Leader and Follower serial port connections.
• Read Leader joint angles in real time.
• Control the Follower arm to follow the Leader arm.
• 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 name
FOLLOWER_PORT_NAME	/dev/ttyUSB1	Follower port name
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. Check before operation
2. Make sure the USB connection is stable.
3. Ensure there are no obstacles around the robotic arm.

4. Check that the power supply is working properly.

5. Emergency stop

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

7. If anything abnormal happens, unplug the USB cable to disconnect.

8. Joint limits

9. Keep the Leader arm within a safe angle range during operation.

10. Avoid fast movements with large amplitude.

11. Power management

12. Use a stable 12V 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 name is correct.
• Try a different USB port.
• Verify that the driver is installed correctly.

Q3: Control frequency is too low?

• Check whether serial port communication is working properly.
• Reduce the load from other running programs.
• Use a USB 3.0 port for better performance.

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

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

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📖 More Documentation

• Main Project README - Project overview
• ROS2 HUMBLE Guide - ROS2 control method
• Lerobot Guide - Lerobot framework integration

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🔗 Related Links

• FashionStar UART SDK
• FashionStar Official Website

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📄 License

This project is open sourced under the MIT License.

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👥 Acknowledgments

• Thanks to FashionStar for the hardware support and SDK.

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Enjoy using it. If you run into any issues, feel free to submit an Issue.