NMEA output in Simulator mode

I’m using AgOpen GPS as simulator to explain guys how to work with Autopilot.
But now i need to use demo stand with electric drives and need to get NMEA from simulator to stand.
Please tell me how to get serial NMEA from your simulator to outside thru COM port on laptop.
P.S.:Previously i’m using Ag Leader gps simulator but it has poore functionallity.


This looks like an uncommon request. Usually, on a non simulation setup, the NMEA messages are generated by a GNSS module able to perform RTK calculations. Then, AOG listens to these NMEA messages to display stuff and to drive the tractor (or any other machine). Thus, as far as I can see this, AOG is never asked to output NMEA, and I don’t know if on simulation there is even NMEA being generated internally. @BrianTee_Admin may be able to confirm this.

it does actually, the class CSim generates a sentence and just throws it in the stream used to parse the nmea. That is why you don’t have to select usb or udp etc when feeding it nmea.

There are some free nmea simulators online - but do you need specifically AOG putting out nmea on a serial port?

Hi guys.
Thanks for answer. I thought you never answer me)))

Yes, I need to get nmea out from Com port on my laptop. Think GGA, RMC, VTG is enough.
As a rule I’m using AG Leader simulator but AG OPEN GPS have good visualization and Autopilot.
Please tell/show me how to do it. It will help me a lot to make experiments in my shop


Well you kind of can’t unless you program a new serial port and take the sentence from CSim class which makes the sentence and output on that port.


Thanks for advice.

What we make:

We create COM3 for output GGA, make it on 115200baud on 10 Hz and transmit simulated position to that COM PORT.

What we have:

We get NMEA out to my tablet. But something wrong with GGA transmitting. Tractor are moving on screen and i see satellite and correction status but doesn’t see speed, heading and Error decrease with higher speed.

I have a stand with 2 electric drives which should spinning when tractor moving but it doesn’t happened without speed getting.

Please advise what can be wrong? What coding system are you using? Why speed and heading doesn’t show?

Below you can find print screens of what we program and picture of my tablet with GPS status colored red.

Thanks in advance,

@ARTEM Did you have any luck getting this NMEA output to work? I too am looking to output NMEA 0183 messages out of my computer to an external device.

Hi Ideroo! Unfortunately i didn’t get any luck in this. Guys from AG open not interested in this soution and they told that it needs some controller to configure COM port there. My friend who is programmer try to write a part of code but there was big gaps in nmea output and it need to spend a lot of time to figure out why is that happened. Now i leave that idea and using AgLeader simulator for my needs.

Please let me know if you will have any success on that. Thanks

If you download the current version, there is a udp simulator - stand alone. Does that help?

With version 5 now everything is very different especially with the sim since AgOpenGPS no longer does any nmea parsing as that is AgIO’s job.

@BrianTee_Admin Thanks for the reply. I’m not sure what the UDP Simulator - Stand alone does.

I have set up a custom UDP IP Address. In AgIO I see messages being sent (confirmed with Wireshark), however it looks like AgIO is not receiving the Lat/Lon from AgOpenGPS. Screenshot attached. Is there somewhere in the setting that will route the Sim Lat/Lon out to Ag IO?

UDP Debugging

@ARTEM Where can I find AgLeader simulator software? I think it may be good for my requirements but I can’t find a download link for it anywhere.

AgIO generates its own lat lon from the nmea rec’d.

Doesn’t the sim in the folders within the release work for you? It does every sentence.


Ah HA! I didn’t realized UDP_Sim was a separate application. I was able to stimulate AOG with it. I think I’ll be able to build the NMEA output over com port using the the UDP_Sim code.


Hi Ideroo
Would you be so kind to share with me how you get GGA from COM port on AgOpen GPS. As i understand the program cannot output it to com port now and it needs to add some code inside? I’m not so familiar with it.

GGA would have to come from AgIO since it never goes to AgOpenGPS. You would have to write all the code to output GGa from AgIO on its own serial port.

Yes, just make a serial port and output the same as the udp. UDP was used so it could feed AgIO anywhere on the network as well as on its own machine. Or if no network, use as the IP.