Developer Guide: NMEA 2000 Core & IoT CAN Bus 🔌🔌

Athena Helm integrates with standardized marine electronics using an optimized local micro-controller socket simulator and native CAN-bus parser.

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🧭 Hardware Interface Architecture

For real vessels, NMEA 2000 (IEC 61162-3) operates in standard CAN (Controller Area Network) profiles at a raw 250 kbps baud-rate.

 [NMEA 2000 Backbone] ──┬── [Actisense NGT-1 USB Gateways] ── [Raspberry Pi Node Server]
                        ├── [GPS/Compass Transceiver]
                        └── [Yanmar Engine Microcontrollers]

🔌 Actuator Control & PGNS

Athena maps physical yacht status properties to common NMEA Parameter Group Numbers (PGNs):

PGN	Description	Tracked Core Values
127250	Vessel Heading	Pitch, Roll, Heading, Magnetic Variance
130306	Wind Data	Apparent Wind Angle, Apparent Wind Speed, True Direction
127508	Battery Status	State of Charge, Output Amps, Voltage Levels, Temperature
127505	Fluid Level DB	Bilge Sump Sump Rate, Fresh Water Tank, Diesel Level

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🛠️ Testing via JSON API Trigger Frame Injection

To test specific alarms or trigger emergency bilge actions on your boat's digital twin panels during simulations, developer post requests can target:

POST /api/nmea/inject-frame

{
  "pgn": 127505,
  "data": {
    "sump_pump_overflow": true,
    "bilge_height_inches": 3.4
  }
}

The system dashboard will instantly pivot, launching thermal warnings and starting extraction pumps within <12ms.