SeaTalk1 to NMEA 0183 converter, DIY

Updated 2024-08-30 ! 

!! Another SW solution is available for RPi 5 here ! using the same HW.

Thanks to Thomas, (the guy with the nice marine interface board), it's now possible to decode, one way, the SeaTalk1(ST1) sentences in a pretty simple way. You just use OpenPlotter(OP) and/or SignalK(SK) and an Optocoupler.

The thing that made it, is that Thomas has released a "how to" and Python source code, that will read the data from a GPIO pin on the Raspberry Pi, (RPi), and format it so the standard parser in SignalK can translate it to SignalK delta format. It is then available as NMEA 0183. It's even possible to send the data in to a NMEA 2000 network, with a proper hardware interface.

Raymarine E120 & E80 backlight failure

Just the other day the backlight for our classic Raymarine E 120, Navigator(MFD), stopped working.

It's from 2006 so I'm not surprised that things happen. You may wonder why we keep it instead of buying a new one but the thing is that we have 2 installed together with a well functioning radar so buying new stuff will be a hefty price tag.

After some Googling I found out that the backlight is produced by a CCFL, a type of neon light, and can give up after some years.

The Googling also gave some tips how to change to a LED backlight. The picture above is showing a test with a short LED light strip to verify the solution, with dimming working, and checking the health of the MFD.

NMEA WiFi gateway

Updated 2023-11-06 !

I have searched for a solution transmitting the NMEA data, from the navigation network, via WiFi, to for example iSailor or other Tablet/Phone applications.

Most of these applications just accepts NMEA0183(N1) but many boats are also using SeaTalk 1(ST1) and NMEA2000(N2K).

This post will cover, kept compact, my best findings covering both a DIY and a commercial approach to handle the different protocols.

SignalK, measuring temperature

Updated 2023-11-05 !

An introduction to the SignalK, Marine application, is given here.

A very easy way to measure temperature with Raspberry Pi, RPi, is to connect one wire (1W) DS18B20 (DS)temperature sensors direkt to the RPi GPIO.

Here You find a post where the temperatures are transfered via WiFi

Understand/Install Openplotter/OpenCPN/SignalK, II

Updated 2023-10-16 !

This post is the second post explaining the purpose with, and quick/simple install instructions for, OpenPlotter(OP) and some other applications that can be installed with OP. 

The first post is found here and in this post we will proceed with the install of OpenCPN(OC).

OpenCPN

Install

In OP:s "Application Meny => Other => Settings" app,  mark "OpenCPN Installer" and click on "Install", at the upper right. 

Seatalk 1 and NMEA2000 combined

Updated 2023-01-20 !

Our boat was delivered, 2006, with just Raymarine equipment using network Seatalk 1(ST1), and some NMEA0183(N1). Updates and additional equipment will use the newer NMEA2000(N2K). We will keep the two well functioning Raymarine 12”, E120, and the radar. In addition, for Navigation purposes, we use the iPad app iSailor.

The easy way to combine ST1 with N2K is to use the Raymarine Seatalk 1 to Seatalk NG(STNG) converter, Raymarine E22158. STNG and N2K is the same protocol, with some dialectal differences, but have different cabling.

Don't miss this post where I'm presenting additional solutions, including a NMEA WiFi gateway, and add ons.

NMEA 2000 temperature sensor, wet exhaust

In former posts I used the temperatur sensor DS18B20, in several applications, but now it was time for the boats exhaust temperature and checking out YDTC-13 from Yacht Devices(YDTC). (But please note that the YDTC can be used in any temperature application.)

When you are boating, using the engine, it's very important that the cooling water always is present otherwise major damages can follow. In "wet exhaust" systems it's easy to get the temperature which I posted here.

Raymarine AXIOM and NMEA0183

Updated 2021-07-24 !

Many newer MFD:s don't have any NMEA 0183(N1) connector. The  Axiom don't even have any Seatalk NG connector anymore, just the Device Net micro connector for NMEA 2000. Loosing the  N1 info, too for example the old VHF (position data for DSC), could be a problem so how to solve it ?

Some solutions

• Pick N1 data from the AIS
• NMEA 2000, N2 to N1 konverter
• SeaTalk NG, NG to N1 konverter

Volvo Penta NMEA 2000 Gateway

Updated 2021-06-15

It's always nice to have ALL information at the same place, navigator/plotter, when You are out with the boat. 

What could be missing is the engine information/data. If You have a Volvo Penta from 2006 or later it could be pretty easy.

There are some "standard" NMEA 2000 gateways to choose from, for example; 

• Volvo Penta has it's own 22813366, 3889758
• Raymarine ECI-100
• Maretron J2K100
• .....

Raspberry Pi measuring Voltage

I'm always a little confused that as soon as someone wants to get an analog measure to a Raspberry Pi(RPi) they are often taking a detour via an Arduino/ESP or some other microcontroller. 

Why not just take an Arduino peripheral and use it together with a RPi ? 

In my case I needed to measure the voltage across a fresh water tank level sensor in our boat, but i could be any DC voltage. Hints for sending the data to a Signal K(SK) server is found below. 

In this post I will use an ADS 1115(AD), or ADS 1015, as AD converter.

OpenPlotter, V1, quick install guide

Updated 2020-01-13 !

OpenPlotter is;

• A complete boat navigation system
• Includes OpenCPN, Chart plotter navigation
• OpenSource, so it's free !
• Running on Raspberry Pi(RPi)
• Its hardware is cheap
• Running on Unix, so its reliable

I really don't recommend this old OP 1, instead check out OP V2, stable, which works very well ! 

NMEA WiFi gateway II

My thoughts, about NMEA WiFi have finalized ? since my first post in the subject and the Yacht Devices YDWG-02N is now installed in my NMEA2000/ST/NMEA0183 network and works just fine. 

I'm already using Raymarine ST => ST NG converter but otherwise I had bought the YDNR-02 instead which should have done the same job.

Please find some thoughts from the installation below.

Boat navigation network

In a former post a I presented our approach to mix a modern NMEA 2000(N2) network with the older Raymarine ST 1 network, installed 2006.

During the Years it has grown and been added with new functions. The pictures to the right is the actual layout.

The first add on was a N2 GPS described here.

ST NG software update

Updating the software for the ST1 to ST NG converter, Raymarine E22158
The easiest way to find the right software is to visit
http://www.raymarine.com -Support -Software updates 
And for this case then -Networking -Seatalk NG converter
Since we have an E 120 just I click on the link for E series Classic and the software will be downloaded.
Open up the folder where the software "landed"

NMEA2000 GPS added

Adding a NMEA2000 GPS and add an additional cable to E120

So what happens when You add a NMEA2000, N2K, GPS to the network ?

Nothing much actually. No conflicts. The E120 is still "hocked" on the old Raymaring RS125 GPS and the Garmin GMI 10/20 shows the info from the new NME2000 GPS with some additional data compared to the old GPS.

The chosen GP:s is Garmin GPS 17X because it was on sale for just 20 €.  It is mounted behind the instrument panel.

The picture shows the GPS at the right and the ST converter in the upper part

Network diagrams

Network diagrams Seatalk 1, Seatalk HS, NMEA0183, NMEA2000

To get en idea how the network is configured please find the links below

The diagrams are divided into a Raymarine part, Seatalk/NMEA0183, and a Garmin part, NMEA2000

The respective diagram is vertically divided in 3 parts depending on location.
Helm, tecnical storage room and flying bridge

Boat network ST1, NMEA0183, ST HS

Boat network NMEA2000