ST4000 Compass/Autopilot Data to OpenCPN?

[Ryban]

I have an old ST4000+ that still works great. I would like to get the fluxgate compass data into OpenCPN (mainly for the radar), but am not really sure where to start here.

It seems like a Seatalk -> NMEA0183 converter is going to be required at a minimum, but I'm not even sure if the compass heading will be an output string in the NMEA0183 data. I have a means to get NMEA0183 to USB already.

[Tupaia]

It does output compass bearing. You will need a Raymarine E85001 interface to convert the raw Seatalk to NMEA 183. These are hard to come by but there is a Youtube vid that has a guy build his own from scratch. You might also look at Quark mutiplexors I think they also have a Seatalk to wifi converter as an add-on.

[Franziska]

Originally Posted by Tupaia

It does output compass bearing. You will need a Raymarine E85001 interface to convert the raw Seatalk to NMEA 183. These are hard to come by but there is a Youtube vid that has a guy build his own from scratch. You might also look at Quark mutiplexors I think they also have a Seatalk to wifi converter as an add-on.

No Raymarine interface needed, if you can't get one cheaply.
Many NMEA multiplex devices can read Seatalk.
The ones from Shipmodul for example do.
We have a Shipmodul multiplexer and it reads the Seatalk data and NMEA data from other devices..

[Corsair63]

From the information of your device it has no NMEA output (it has only input) attached picture.

so you'll need a multiplexer with Seatalk connection.

Shipmodul is the best, but expensive and has no stock for the time being.

Quark-Elec has some cheap multiplexers with Seatalk feature.

also this one that are really cheap but can't tell you anything about:

https://www.vela-navega.com/index.ph...g-multiplexers

I have ST6002 connected via Seatalk to Shipmodul MiniPlex-3E-N2K and I get all the information send by the autopilot.

now only need to know how to control in from computer

[Ryban]

I gotta learn to use the search feature. I found an identical thread here:
https://www.cruisersforum.com/forums...lk-173060.html

I am pretty electronics-savvy and could probably create a converter based on the YAPP design, but I free time is not one of my luxuries right now, so I ended up finding a relatively cheap E85001 bridge on ebay and purchased that.

[Ryban]

Update on this.

Finally got around to fiddling with the E85001 bridge I got on ebay for cheap. I fed this into a $15 DTech RS422 to USB dongle, and was flummoxed for a while as I wasn't getting data into the computer running OpenCPN. I checked the serial port for data as well -- nothing.

The NMEA output from the E85001 is a +/- pair that I fed into the +/- RS422 connections on the dongle. I instead tried the RS232 output from the E85001 bridge. That produced data on the serial terminal, but it was garbage. After checking the output from the NMEA ports on an oscilloscope it was clear that the bridge was outputting something, but it wasn't showing up on the computer. Out of ideas, I just started moving the wires around on the dongle, and after swapping the polarity, I suddenly got the NMEA sentences I was looking for. This is probably just a novice error when working with NMEA 0183/RS422 type signals, but thought I'd offer my experience in case it saves someone else's time in the future.





Now I just need to figure out how to adjust/re-calibrate the fluxgate compass, as it's off by a good 20 degrees (I compensated above in the radar settings).

[Corsair63]

Hi Ryban,
Read in the manuals, because there is a procedure to swing the vessels and auto calibrate the fluxgate, at least in my ST6002 it is.
in mine is searching in the autopilot the feature and swing the vessels twice at slow speed and there are other adjustments that used to be clearly explained in the user manual.

[rgleason]

Ryban I had similar experience getting a gps puck connected to my dsc vhf. Massive struggle before I tried switching the wires.

[Corsair63]

Originally Posted by rgleason

Ryban I had similar experience getting a gps puck connected to my dsc vhf. Massive struggle before I tried switching the wires.

I don't know how I do? I read all the manuals before starting any new installation but for unforeseen elements at last I must switch the wire connections

but worst was when fitting a switch in the power supply of the computer and myself was praying red with red & black with black, I did the job connect the computer and pouring smoke by the HDMI connection, well you could understand what I did.
red with black, I pulled from the wire and by means of miracle the computer was still working. and me banging my head with the ship's bulkhead calling myself stupid and don't know how many times.