NMEA wiring issue with Garmin 541S and Uniden UM380

[dingbat]

Re: NMEA wiring issue with Garmin 541S and Uniden UM380

I thank you guys very much.
Ok, then, I guess I can not finish wiring this yet as I don't have an accurate color key to identify uniden's GPS Data In (-).
I agree that this is not rocket science, but if you have never dealt with it, and are trying to learn some of it, you really need good and accurate advice... give a man a fish...

According to your manual, Page 29....BRN and WHT are NEMA OUT and GRN and YEL are NEMA IN.
http://www.uniden.com/content/ebiz/uniden/resources/ownersmanuals/UM380om.pdf

ONE MORE TIME........
From Radio to GPS = Uniden Brown or white (output) connects to Garmin Brown or violet (input)
From GPS to Radio = Garmin Blue or Grey (output) connects to Uniden green or yellow (input)
Blk to blk + bare

 

[KRH1326]

Re: NMEA wiring issue with Garmin 541S and Uniden UM380

I think you are missing the point. THEY CHANGED THEIR WIRING HARNESSES COLOR CONFIGURATIONS WITHOUT ANY DOCUMENTATION. Uniden also uses polarity in their scematics, so saying that this color or that color can be used is not accurate. The wording as per their directions, on page 29, SPECIFICALLY stated to connect their yellow to Garmins Blue and the bare to Garmins ground. Furthermore, they SPECIFICALLY stated, on page 31, to connect their brown to the negative (-) wire of your chartplotters NMEA data input. And their WHITE to the positive (+) wire of your chartplotters NMEA data input.

They had their yellow going to Garmin blue, and it actually needs to go to brown.
AND THERE IS NO WHITE WIRE

It is difficult enough to undertake a task that is new to you, with HORRIBLE manufactures diagrams and instructions that do not use clear and accurate descriptions, let alone that their directions are no longer applicable or current, then to ask for help, and receive short curt response, that appear sarcastic and implying that it is very simple, duh, "one more time".. cant you understand this???
This OR that to THIS or THAT

What about the orange wire?
This would not have worked:
ONE MORE TIME........
From Radio to GPS = Uniden Brown or white (output) connects to Garmin Brown or violet (input)
From GPS to Radio = Garmin Blue or Grey (output) connects to Uniden green or yellow (input)
Blk to blk + bare

without the orange wire. That orange wire is not in ANY directions.

I dont want to sound ingrateful, I do appreciate the help, but even the answers were confusing, the bottom line is it got figured out and verified.

Thank you all.

 

[dingbat]

Re: NMEA wiring issue with Garmin 541S and Uniden UM380

This would not have worked:

Explain why this would not have worked.

From Radio to GPS = Uniden Brown or white (output) connects to Garmin Brown or violet (input)
From GPS to Radio = Garmin Blue or Grey (output) connects to Uniden green or yellow (input)
Blk to blk + bare

Keep in mind that the nomenclature Input, RX and - are one and the same and output, TX and + are one and the same.

Yes... I did take polarity (off the schematic) into consideration when making the determination which wire connect to which

 

[KRH1326]

Re: NMEA wiring issue with Garmin 541S and Uniden UM380

These are reasons why:

# 1 Are you aknowledging the fact, that the diagram that you are looking at is not accurate, because the harness that is being utilized, has less wires and a different color coding?
# 2 From Radio to GPS = Uniden Brown or white (output) connects to Garmin Brown or violet (input) INCORRECT
The Uniden brown is not used and there is no white.
#3 From GPS to Radio = Garmin Blue or Grey (output) connects to Uniden green or yellow (input) PARTIALLY CORRECT
Garmin Blue DOES go to Uniden GREEN only, as the UNIDEN yellow is needed to connect to Garmin Brown.
#4 Blk to blk + bare is PARTIALLY CORRECT. The Uniden Orange must also be grounded.
#5 Keep in mind that the nomenclature Input, RX and - are one and the same and output, TX and + are one and the same. INCORRECT
The explanation that I got from Cust Service is this:
The - and + have nothing to do with Rx, IN, Tx or OUT. For a circuit to work, and current to move ( or to be read ) there has to be polarity. That is why in DC electric there is a positive and negative terminal. Device A needs to put its signal out, in positive polarity, through its Tx (transmit) or OUT wire, into device B's Rx (Receive) or IN [ still in + polarity ]. For device A to send that signal, for device B to read it, device A still needs to have that signal ( current) returned to its - pole, OR THERE IS NO SIGNAL OR CURRENT ( closed circuit) In this case Garmin does its -NMEA ( thru common ground ) done internally, in the unit. That is why there are no Garmin wires labeled with + or -. The Uniden uses common ground BUT YOU MUST MAKE THAT CONNECTION IN THE FIELD ( it is not done internally with factory wiring.) In this case it is the Uniden Orange wire and it must be grounded to the same wire, as the Garmin. The Uniden bare wire is merely a shield (that happens to be grounded) to eliminate interference.

In simple terms, the signal has to travel from one device (+) to the other, be read by the 2nd device, then return to the - side of the initiating device.

If I had made only the three connections that you listed, even if they were the right Tx/Rx or IN/ OUT combinations, the devices couldn't "speak" to each other because without that Orange NMEA- wire connected, there would be no common ground for the NMEA signal to complete a closed circuit.

I could be wrong and maybe I really didn't learn anything studying this all weekend, but I can tell you this:
It is in and wired like this :

Uniden GREEN (NMEA + In Rx) is wired to Garmin BLUE (NMEA port 1 Tx Out)
Uniden YELLOW (NMEA + Out Tx) is wired to Garmin BROWN (NMEA port 1 Rx In)
Uniden ORANGE (NMEA - In Rx) is wired to Garmin BLACK grounding wire.
Uniden BARE/SHIELD is wired to Garmin BLACK grounding wire.

And it is working perfect.

 

[NYBo]

Re: NMEA wiring issue with Garmin 541S and Uniden UM380

Glad you figured this mess out.:encouragement:

 

[jhebert]

Re: NMEA wiring issue with Garmin 541S and Uniden UM380

...It is in and wired like this:

Uniden GREEN (NMEA + In Rx) is wired to Garmin BLUE (NMEA port 1 Tx Out)
Uniden YELLOW (NMEA + Out Tx) is wired to Garmin BROWN (NMEA port 1 Rx In)
Uniden ORANGE (NMEA - In Rx) is wired to Garmin BLACK grounding wire.
Uniden BARE/SHIELD is wired to Garmin BLACK grounding wire.

And it is working perfect.

I am glad you got the electrical connection configured correctly.

That is just the start of the interface problem, as you also need to set the port configurations to the proper baud rates. Usually NMEA-0183 is set for 4800-bps. Perhaps both devices were already set for this and did not need any further configuration.

Now with the electrical connection made and the two ports talking and listening at the same baud rate, we have to configure the data being sent between them. You have to configure the GPS receiver to send the correct data to the radio. Can you tell us what the radio manufacturer said was the proper NMEA sentence to send to the radio?

And, what sentence, in fact, did you configure to be sent from the GPS receiver?

Perhaps, the GPS was just set by default to send the correct sentence for the radio. But one should be aware of this additional step in the interfacing of the two devices, as it often occurs that one or another of the devices is rather particular about what NMEA sentence it wants to send or receive.

 

[KRH1326]

Re: NMEA wiring issue with Garmin 541S and Uniden UM380

I do not have the unit or paperwork, infront of me right now to check for actual terminology.
But this is how it went. Neither unit had been powered up, both brand new. I turned on the radio and fiddled with it. I listened to WX and fooled around surfing some chanels. Then I turned on the GPS. It went into a "Set up for first time" activity. It started asking questions about units of measure, coordinates format, language.... blah blah blah, then it asked about the NMEA port 1 and I entered YES.... is it an AIS...NO... some Q&A and the set up was done. I looked at the vhf and the coordinates on the gps were being displayed right on the radio screen along with heading speed etc.

 

[hippie2]

KRH1326, I have been looking for an article like this for over a year! I too have a Garmin 541s and am attempting to connect it to a Uniden UM415 that has DSC built into it. I have the same articles and pics as you have, saved from my search over the past year. I'm not stupid but I can not understand any of this. All I want to do is hook up the radio to my chartplotter so when someone talks their location will appear on my chartplotter along with the GPS numbers of their location. I am sure the wires on a Uniden 380 and Uniden 415 are the same coming out the back. So what colors go to what colors ? On your baud question, a factory rep told me to set my Garmin 541s to "Garmin Standard" for 0183 applications. Thank you, Bob

 

[GA_Boater]

Almost 2 years old and KRH1326 has not visited since May of 2015. Start a new topic, hippie.

Closed.