NMEA Seatalk et al to lap top

yotter said:
We probably need a little more info on what you want to do, for a start NMEA0183 is not encrypted so no need to decode, are you thinking of seatalk which is encrypted. I use NavMonPC to display NMEA data, its old and clunky, a bit like me but works well.
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It might not be encrypted (then he might have asked for it to be decrypted) but the data is encoded - if you don’t know how, or have a bit of software to do it for you the sentences are not exactly easily human readable.

I think the what are you trying to do question is fair though - I have a raspberry pi which is able to do the same sort of stuff as Ship Modul for a significantly lower cost, but higher hassle/learning curve factor. I’ve never felt a desire to connect a laptop to it.
 
yotter said:
We probably need a little more info on what you want to do, for a start NMEA0183 is not encrypted so no need to decode, are you thinking of seatalk which is encrypted. I use NavMonPC to display NMEA data, its old and clunky, a bit like me but works well.
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No version of Seatalk is encrypted but all are encoded so need decoding. They are all closed standards, as are NMEA0183 and NMEA2000 which also need decoding but not decrypting. NMEA0183 escaped into the public domain very quickly as the encoding is simple and was quickly reverse engineered. Seatalk 1 was reverse engineered by Thomas Knauf and NMEA2000 by Timo Lappalainen. As far as I am aware the Raymarine extensions to NMEA2000 which are found in SeatalkNG are still unknown but I doubt that they are encrypted.

NMEA0183 is a text based encoding making it easy to decode - you can do it by looking at it with a bit of knowledge or guessing. All the others are binary encoded meaning that they are just a stream of numbers making them harder to read by humans, but that is not encryption, and they aren't encrypted. The Enigma cypher was a stream of letters making it easy to read, but encrypted meaning impossible to understand (they thought).

Other marine network protocols are closed but less well publicly understood. Good progress had been made on reverse engineering Micronet but Raymarine has now deprecated it. Raynet as far as I know is still unknown but I doubt that it is encrypted.

The reason why these protocols are unencrypted is because at the time of their specification, especially Seatalk 1 and NMEA0183, cryptography was computationally expensive requiring additional or upgraded hardware and software. The cost/benefit analysis didn't show that it made sense to implement when the value of the data is minimal. Times have changed and it is now cheap and easy to do.
 
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No idea for a MAC .... but literally any of the basic PC based Charting progs such as Seaclear etc will display the sentences as they are received via USB. I would assume that there are MAC prog's doing same ?

Seaclear as example can then 'pass thru' if needed the sentences to other gear to use ...

Online there are many sites that list the NMEA sentence strings and their meaning.
 
yotter said:
We probably need a little more info on what you want to do, for a start NMEA0183 is not encrypted so no need to decode, are you thinking of seatalk which is encrypted. I use NavMonPC to display NMEA data, its old and clunky, a bit like me but works well.
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More details;-
I have a (n old) RM GPS receiver.
Vertex Standard VHF transceiver
Two E80 plotters connected by RM "router/multiplexer
A NASA "radar" (ie AIS receiver)
A Matsutec AIS transmitter/receiver (with built in GPS)
A number of instruments all Seatalk.

I would like to connect the lot.

The vhf radio needs NMEA 0183 at 4800 baud.
The GPS outputs position either as NMEA 0183 at 4800 baud or /Seatalk.
The E80 can receive at either 4800or 38400 baud (but not both) or Seatalk.
The NASA "radar" needs NMEA 0183 (presumably at 4800 baud.
The E80 can read Seatalk, Setalkhs (= RM ethernet), and NMEA 0183 but at only 1 baud rate (4800 or 38400).
I bought a Quark "Combiner/mu;tiplexer" in the hope that it would produce workable solution.
As an engineer, I like to understand!
 
ok but where does the laptop fit in?
Why keep two AIS and GPS ? If the answer is redundancy then would it be better if they were kept on a separate “network” with the VHF and the rest were linked?

Can the E80s both connect to different devices/standards or does one need to be set as master/slave?

Which quark box did you get? What is it not doing that you want?
 
ylop said:
ok but where does the laptop fit in?
Why keep two AIS and GPS ? If the answer is redundancy then would it be better if they were kept on a separate “network” with the VHF and the rest were linked?

Can the E80s both connect to different devices/standards or does one need to be set as master/slave?

Which quark box did you get? What is it not doing that you want?
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In order;-
The laptop "may" help me to understand the basics (I used to understand RS232, 422 and the like and, indeed have a patent for another self clocking data transmission system).
I like to understand.
The reason for the NASA AIS is that it is low power and ticks along in the background without draining the batteries. The NASA AIS needs NMEA 01831 which is a constraint.
That the E80s may connect to different sources, is something I hadn't considered and worth exploring.
QKA031 is the Quark device. It defies my comprehension. (one is 85 coming on 86!, where is a child of eight when one needs one?).).
 
Graham_Wright said:
More details;-
I have a (n old) RM GPS receiver.
Vertex Standard VHF transceiver
Two E80 plotters connected by RM "router/multiplexer
A NASA "radar" (ie AIS receiver)
A Matsutec AIS transmitter/receiver (with built in GPS)
A number of instruments all Seatalk.

I would like to connect the lot.

The vhf radio needs NMEA 0183 at 4800 baud.
The GPS outputs position either as NMEA 0183 at 4800 baud or /Seatalk.
The E80 can receive at either 4800or 38400 baud (but not both) or Seatalk.
The NASA "radar" needs NMEA 0183 (presumably at 4800 baud.
The E80 can read Seatalk, Setalkhs (= RM ethernet), and NMEA 0183 but at only 1 baud rate (4800 or 38400).
I bought a Quark "Combiner/mu;tiplexer" in the hope that it would produce workable solution.
As an engineer, I like to understand!
Click to expand...
have you considered getting Openplotter and running on a Raspberry Pi with a Macarthur hat board on it? You need to be a bit techie, but the Macarthur hat has ports for NME0183, Seatalk and NMEA2000 and can do all the converting, plus it also has the option of a WIFI hotspot.
 
Parabordi said:
have you considered getting Openplotter and running on a Raspberry Pi with a Macarthur hat board on it? You need to be a bit techie, but the Macarthur hat has ports for NME0183, Seatalk and NMEA2000 and can do all the converting, plus it also has the option of a WIFI hotspot.
Click to expand...
No!
I'm trying to understand what exists not add to the complication!
The Quark device already has wifi.
 
Pye_End said:
Are you asking for laptop software to show the 0183 detail?

Pretty sure OpenCPN can do this for you.
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But I’m not sure it will help the OP - he already had devices on his boat which will display the content if correctly configured… so adding another system with uncertainty about wiring, baud rates etc isn’t going to help him work out his jumble (unless i am misunderstanding his challenge).
 
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