Adam - I have an ST60 Multi at the nav station ...
I have an ST60 Multi at the nav station and I found out that it is supposed to support Seatalk to NMEA0183 conversion bidirectionally. I'm currently reading data via an optocoupler but I'm interested in switching to the NMEA solution both for putting data onto the Seatalk chain for the Autopilot, but also so I can move to the Pi 5 since Seatalk isn't supported on the PI 5 yet.
I'm using an RS422 USB converter. It has a TX and RX +- Which I've hooked up to the connections on the back of the Multi. I did have to go into the Multi's settings and turn on NMEA. Only sad part is that I don't seem to be getting anything at all. I can see the USB device on the Raspberry PI. When I use the screen command on the command line I get no data. The lights on the converter aren't lighting up for tx or rx. Any ideas?
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There is a ground on the board that I don't have hooked up to anything. Not sure where I would connect that.
if 'Tx+ to Rx+' and 'Tx- to Rx-' doesn't work, reverse polarity, so do 'Tx+ to Rx-' and 'Tx- to Rx+' I also had to do this and it is identified in the Openplotter docs
What the heck I swear I've read all the docs and didn't see that. Ok let me give it a try.
@Jason_SV.Apres|Hunter336|WI Does that also apply to inbound? I'm trying to read NMEA first before writing.
You're saying it should be like this?
I'm hoping to avoid spending 200 bucks on a seatalk nmea multiplexer.
First try TX+ to NMEA IN+ , TX- to NMEA IN-, RX+ to NMEA OUT+, RX- to NMEA OUT-
if that doesn't work reverse the polarity as you have shown
Ya sadly I think I've tried both 😦
I tried the way you just explained first and didn't get anything.
Swapped polarities and also nothing.
I wonder if the unit is defective. I did confirm I have NMEA output switched on in the settings.
I will send a pic of how mine is connected up when I get to the boat, over the weekend. It is worth checking what messages the device would send out just to check if there would be traffic, I would still expect trafic from Signalk to NMEA. Do you have the serial connection setup correctly in Openplotter or SIgnalK?
So I did get the Signalk to NMEA working. I am getting lat, lon from the Maiana going through the nmea in. But all quiet on the out.
That’s good then because that means you have the polarity correct. Now it is down to getting the out to work, and you could alway go the ST1 route for that!!
Ya I have the ST1 out working but I want to get to a solution that can utilize the pi 5. I'm not confident that's going to get resolved anytime soon.
good point, I hope it does. I do wonder if the Signal K team has any insight into switching the pigpio library to a different one that works with RPi5 and can handle the 9bit (a bit beyond me here). I know Sailoog is looking at libgpiod - gpiomon and trying to get further help. its a bit beyond me, but I will test as soon as they have something to try. There are a few Yakbitz products that will do it if you are stuck: https://www.yakbitz.com/ST1toWiFi.aspx. I had one, prior to the Optocoupler solution, but I let the smoke out of it...
Hate it when that happens. I think I'm just going to pick up a digital yacht ST1 USB module and call it done.
The weirdest thing just happened, I didn't change anything about my setup and now all of the sudden I'm receiving data. One thing that's interesting though is I'm definitely not getting all of the data I am over the raw ST1 connection. So I feel better about my decision to go with the converter. So weird though I really have no idea. I just left it connected with instruments on for 2 days and now all the sudden bam. Really awesome now that I'm starting to see so much signalk data to look at.