Comm Node

ROS2 Communication Node for RoboMaster AutoAim System

---

Overview

Comm Node is a ROS2 communication package designed for RoboMaster robots.

The node receives targeting data generated by the AutoAim system, packs the data according to a custom communication protocol, and transmits it to the lower-level STM32 controller through a USART serial interface.

It serves as the bridge between the high-level perception system and the embedded control system.

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Features

• ROS2-based communication architecture
• Subscribe to AutoAim target data
• Custom protocol packing
• USART serial communication
• Low-latency data transmission
• Modular design
• Easy integration with STM32 controllers
• Support for custom message definitions

---

System Architecture

+----------------+
|    AutoAim     |
| (Perception)   |
+--------+-------+
         |
         | AutoaimData.msg
         v
+--------+-------+
|   Comm Node    |
| Protocol Pack  |
+--------+-------+
         |
         | USART
         v
+--------+-------+
|     STM32      |
| Lower Controller|
+----------------+

---

Communication Flow

Camera
   │
   ▼
YOLO Detection
   │
   ▼
PnP Solver
   │
   ▼
Kalman Tracker
   │
   ▼
AutoAim Result
   │
   ▼
ROS2 Topic
   │
   ▼
Comm Node
   │
   ▼
Protocol Packing
   │
   ▼
USART Transmission
   │
   ▼
STM32 Controller

---

Sequence Diagram

┌─────────┐
│ AutoAim │
└────┬────┘
     │ Publish AutoaimData.msg
     ▼
┌────────────┐
│ Comm Node  │
└────┬───────┘
     │ Receive Data
     ▼
┌────────────┐
│  pack.py   │
└────┬───────┘
     │ Build Frame
     ▼
┌────────────┐
│   USART    │
└────┬───────┘
     │ Send Packet
     ▼
┌────────────┐
│   STM32    │
└────────────┘

---

Project Structure

comm_node/
│
├── src/
│   └── comm_node/
│       ├── comm_node/
│       │   ├── __init__.py
│       │   ├── comm_node.py
│       │   └── pack.py
│       │
│       ├── resource/
│       ├── test/
│       ├── package.xml
│       ├── setup.cfg
│       └── setup.py
│
├── interface/
│   ├── msg/
│   │   └── AutoaimData.msg
│   ├── CMakeLists.txt
│   └── package.xml
│
└── .gitignore

---

Message Interface

AutoaimData.msg

This custom ROS2 message carries targeting information generated by the AutoAim system.

Example fields:

float32 yaw
float32 pitch
float32 distance
uint8 fire

---

Protocol Workflow

1. Receive AutoAim data from ROS2 topics
2. Extract targeting information
3. Pack data according to custom protocol
4. Generate communication frame
5. Send frame through USART
6. STM32 receives and parses the packet

---

Build

cd ~/ros2_ws

colcon build --packages-select interface
colcon build --packages-select comm_node

source install/setup.bash

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Run

ros2 run comm_node comm_node

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Dependencies

• ROS2 Humble/foxy
• Python 3.10+
• pyserial
• rclpy

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Applications

This package is designed for:

• RoboMaster AutoAim Systems
• Embedded Robotics
• Vision-to-Control Communication
• ROS2 and STM32 Integration

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Author

Jingqi Mei

Robotics • Computer Vision • Embedded Systems

GitHub: https://github.com/AMwhisper