Haswing Cayman 55 GPS v1.6 Protocol Analysis

📘 Protocol Documentation: Haswing-Motor-Control.md

Packet dumps and scripts for reverse-engineering the communication protocol of the Haswing Cayman 55 outboard motor.

Directory Structure

dumps/
├── rs232_mavlink_v1/    # Communication via USR-WIFI232-S module (MAVLink v1)
│   ├── to_motor/         # Packets from remote to motor
│   └── to_remote/        # Packets from motor to remote
├── rs485/                # RS-485 dumps (head ↔ bottom control board, 9600 baud)
└── usr_wifi232_s_config.txt  # USR-WIFI232-S module configuration session dump

Hardware Notes

The USR-WIFI232-S module is located in the motor head. It handles wireless communication between the motor and the remote control (and phones — Android connects via the remote, iPhone likely works directly with the module).

From the config dump:

• Protocol: UDP, server mode
• Port: 14550
• Motor sends data to IP 192.168.1.150 (DHCP-assigned when connecting to the motor's WiFi)
• WiFi SSID: varies per motor, e.g. HSW_m4Cgo (can view via wifi search)
• WiFi key: varies per motor, configurable via official app

The RS-232 bus runs at 115200 baud between the USR-WIFI232-S module and motor head central processor. The RS-485 bus runs at 9600 baud between the motor head and the lower control board.

Scripts

• scripts/parse_pymavlink.py — parse MAVLink v1 packets from a text dump using pymavlink, can be used to parse files from dumps/rs232_mavlink_v1 folder

Setup

py -3 -m venv venv
./venv/Scripts/python.exe -m pip install -r requirements.txt

Usage:

./venv/Scripts/python.exe parse_pymavlink.py <packets.txt>