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Topic: NMEA 2000 Shield (Read 22 times) previous topic - next topic

svDeepPlaya

NMEA 2000 is a closed CAN-BUS standard for marine electronics. It would be awesome to have a shield that can accept the standard NMEA 2000 or that has a screw down terminal to accept bare wires.

NMEA 2000 supplies both power and data in it's cable. Not sure if it's adequate to power the ardunio.
http://en.wikipedia.org/wiki/NMEA_2000

If someone out there can handle the hardware and board side of things, I could help do the research.

Thanks,
-p

estratos

Hi,

Building a CAN shield for the Arduino is quite simple. You just need a SPI-based CAN controller (ex: MCP2515) and a CAN interface (ex: MCP2551). The N2K bus typically provides 12VDC so you will need a regulator in order to power the arduino and the shield, and some kind of optical isolation between CAN interface and CAN controller if you want to stay clean. This is just for the physical side of the engine. Then you'll need to implement all the N2K protocol into the Arduino, but remember the following:

1. NMEA 2000 is a proprietary protocol. You'll surely need to purchase the specification from the NMEA association (several $1000's if I remember well).
2. If you want to certify the product, you'll need to pay for a N2K ID to the NMEA association and later you'll need to pay for the certification process.

I've worked with NMEA 2000 in the past so feel free to drop more questions if you need.

Daniel.

svDeepPlaya

Thanks for the tips!

I hear you on the NMEA 2000 proprietary thing, but many are reverse engineering it... so I'm guessing it's not too difficult.

-p

estratos

Depending on the amount of N2K nodes available on the bus and their outgoing traffic load (some N2K devices are programmed to drop CAN messages every 100 ms), you could find that your Arduino-based node is not capable to accept all the traffic load without loosing packets so If you're thinking in using the Arduino as a kind of PC gateway this could be an issue. For end-device applications the AVR should be fine.

rjason

Hello,

Did you ever get anywhere with NMEA 2k -> Arduino? I'm considering the CAN shield to start playing with it.. don't want to recreate the wheel if you've made progress.

Thanks,
Jason

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