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Newbie jumps in - instant problems
#1
Good day

I have installed a multiplexer with 2 connections

1. GPS antenna on Connection 2
2. Nmea 0183 data from a variety of B&G instruments on Connection 1

I followed the latest directions in Openplotter, which had me bouncing back and forth between OP and Signal K.  It seemed I had been successful but there are 2 problems:

1. The only data being received is from the GPS antenna (confirmed by looking at a dashboard and by viewing the sentences being received).  None of the nmea data from my instruments is being received

2. The diagnostic screen threw the following message:

"Checking OpenCPN...[not running}autostart disabled
The default OpenCPN connection is missing and is not getting data from Signal K.  Please create this connection in OpenCPN:
Network
Protocol: Signal K
Address: localhost
Dataport:3000
Automatic server discovery: not


I'm tempted to re-flash the SD card and start over.  Advice needed...I should say one weird thing I noticed is that the switch to "Suppress nmea events" is ON...that seems to be a bad thing.
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#2
Hi,   the opencpn errors you can ignore, just means opencpn isn't running.

The supress nmea events is usually best left off, when off any nmea0183 coming in automatically gets sent out again to tcp port 10110.

So are you seeing no signalk sentences in the data browser tab on the signalk server? Any nmea data which can be converted to signalk (which is lots) should show up there
[Image: ZXjlyll.png]

Some screen shots would be handy, if no data coming in from instruments it  could be wrong serial port or baud rate wrong...

and from your other thread - sorry no answer to that one, usually this forum is very good but that thread seems to have been overlooked..

[Image: Dv6lrcq.png]

The raspberry Pi should do the job of the multiplexer, though you can end up needing a few serial/usb adaptors.
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#3
PaddyB thanks for your replies.

When I configured the connection the only data I was getting was from my GPS antenna, which is wired to the MUX along with all the B&G nmea data.

Here's when fate intervened...while I was sorting out a potential software problem, the circuit breaker powering the B&G Fastnet2 network tripped. I investigated and found that the power connection to the 4 way hub had shorted out from a corroded and broken pin.

Therefore I need to replace the 4 way hub before I can continue trying to sort out the issue.

The way I see it, the multiplexer is talking to Openplotter...otherwise I wouldn't have GPS data. The issue must be either software (Openplotter isn't setup properly to 'see' the nmea data from the B&G instruments) or hardware (I have mis-wired the connection between the Universal Interface and the multiplexer).

The AIS system shown does not yet exist, but I believe I will connect it directly to the RPi via usb rather than what I've drawn.
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#4
Did you give access to the serial devices ?. Sudo usermod -a -G dialout user-name.
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#5
(2021-10-07, 10:44 PM)verkerkbr Wrote: Did you give access to the serial devices ?. Sudo usermod -a -G dialout user-name.

I followed the instruction listed here:


Other examples — OpenPlotter 2 documentation

My multiplexer is connected to the Rpi with a usb cable.

It's odd that there isn't a comprehensive guide for connecting to Openplotter with a multiplexer. Perhaps I just haven't found it, that or the new openplotter suite of apps are meant to be foolproof and don't require detailed instructions. The link I posted above has a 1/2 dozen steps then immediately move on to discussing outputting data to an autopilot.

The version of Openplotter I downloaded includes RPi OS and I'm not even sure where I would enter commands (sudo)...
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#6
(2021-10-07, 11:36 PM)Island_Moose Wrote:
(2021-10-07, 10:44 PM)verkerkbr Wrote: Did you give access to the serial devices ?. Sudo usermod -a -G dialout user-name.

I followed the instruction listed here:


Other examples — OpenPlotter 2 documentation

My multiplexer is connected to the Rpi with a usb cable.

It's odd that there isn't a comprehensive guide for connecting to Openplotter with a multiplexer.  Perhaps I just haven't found it, that or the new openplotter suite of apps are meant to be foolproof and don't require detailed instructions.  The link I posted above has a 1/2 dozen steps then immediately move on to discussing outputting data to an autopilot.

The version of Openplotter I downloaded includes RPi OS and I'm not even sure where I would enter commands (sudo)...

Unfortunately, there are not enough users writing up their experiences in in the documentation and it isn’t the developers priority at the moment. If you get it working, perhaps you can publish what model you are using and how you set it up.

The fact you have gps working and not the B&G stuff means one connection is working and, I think, points to the issue being with the the B&G connection. One wire seems funny I think there should be a ground reference TX+ and TX- connected to the multiplexers RX channel. If it doesn’t work, try reversing the polarity
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#7
(2021-10-08, 04:51 AM)Techstyle Wrote:
(2021-10-07, 11:36 PM)Island_Moose Wrote:
(2021-10-07, 10:44 PM)verkerkbr Wrote: Did you give access to the serial devices ?. Sudo usermod -a -G dialout user-name.

Here's how I wired the connection between the B&G interface and the multiplexer:




I followed the instruction listed here:


Other examples — OpenPlotter 2 documentation

My multiplexer is connected to the Rpi with a usb cable.

It's odd that there isn't a comprehensive guide for connecting to Openplotter with a multiplexer.  Perhaps I just haven't found it, that or the new openplotter suite of apps are meant to be foolproof and don't require detailed instructions.  The link I posted above has a 1/2 dozen steps then immediately move on to discussing outputting data to an autopilot.

The version of Openplotter I downloaded includes RPi OS and I'm not even sure where I would enter commands (sudo)...

Unfortunately, there are not enough users writing up their experiences in in the documentation and it isn’t the developers priority at the moment. If you get it working, perhaps you can publish what model you are using and how you set it up.

The fact you have gps working and not the B&G stuff means one connection is working and, I think, points to the issue being with the the B&G connection. One wire seems funny I think there should be a ground reference TX+ and TX- connected to the multiplexers RX channel. If it doesn’t work, try reversing the polarity


Attached Files Image(s)
   
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#8
I'm beginning to wonder if the TX- on the B&G Interface should not be grounded as I have done.  I have read that one should connect TX+ to RX+ and TX- to RX-, but in the absence of RX- on the multiplexer, I put the TX- to ground.  I have also read that this could cause a short at worst, and at best is optional.

Does anyone have an opinion on this?
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#9
SUCCESS!!!

The reason my B&G instruments were sending corrupt data sentences to OpenCPN/Signal K was because of an imbalance in my voltage drop.  If you see how I had the units wired above, the Tx+ and Rx+ were travelling about 10cm.  The Tx- and Rx- were grounded to the boats negative ground, which was about 3 meters away.  

I was advised by Steve at Yakbitz to look for a ground closer to the source, and I found the screen inside the Universal Interface itself.  This is grounded inside the UI and matched the length of travel to the Data + lines.

With this new wiring configuration the dissimilar voltage drop disappeared and I instantly got good data from all of my instruments!

$IIHDG,,,,,*67
$IIHDM,,M*0C
$IIHDT,,T*0C
$IIMTW,,C*0D
$IIMWD,,T,,M,,N,,M*44
$IIMWV,,T,,N,A*3B
$IIRMB,V,,,,,,,,,,,,,N*45
$IIRMC,,V,,,,,,,,,,N*44
$IIVHW,349,T,349,M,,N,,K*55
$IIVLW,,N,,N*4D
$IIVTG,,T,,M,,N,,K,N*3B
$IIDPT,3.59,,*7D
$IIGGA,,,,,,,,,,M,,M,,*41

I am now on to creating dashboards and will soon create a link back to my autopilot!  Victory!!!


Attached Files Image(s)
   
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