nmea2000.h File Reference

NMEA 2000 codec (DETWS_ENABLE_NMEA2000) - the marine instrumentation network, built on J1939 over CAN. More...

#include "ServerConfig.h"

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Detailed Description

NMEA 2000 codec (DETWS_ENABLE_NMEA2000) - the marine instrumentation network, built on J1939 over CAN.

NMEA 2000 is J1939 at the transport layer (the same 29-bit priority / PGN / source / destination identifier), so this codec reuses the J1939 id encode / decode (DETWS_ENABLE_NMEA2000 force-enables DETWS_ENABLE_J1939). What it adds is the NMEA-specific Fast Packet transport: messages of 9..223 octets are split across CAN frames using a per-frame control octet (sequence counter + frame counter) instead of the J1939 BAM/CMDT protocol. The first frame carries the total length; continuations carry 7 data octets each.

Pure and host-tested. Drive it from the ESP32 TWAI peripheral or an MCP2515 over SPI to bridge an NMEA 2000 backbone (GPS, wind, depth, engine PGNs) onto Wi-Fi.

Author

Douglas Quigg (dstroy0)

Date

2026

Definition in file nmea2000.h.