Hi everyone, I have successfully assembled my RTK Postcard board with the Portability Shield and updated the RTK Everywhere firmware. However, after connecting it to my GNSS Multi-Band L1/L2 antenna and using my own NTRIP Client, I can’t get a green dot in SW Maps.
I’m sure the hardware setup is correct, and the NTRIP correction data is coming through, but I’m not achieving a green dot. Could I be missing a setting in SW Maps or in the firmware?
Any advice or shared experiences would be greatly appreciated. Thanks!
This might not help, but I’ve had no problems testing the LG290P with the following corrections:
The (3) standard Base Station messages: 1005, 1032, 1033
Plus the MSM4 messages: 1074 (GPS), 1094 (GAL),1084 (GLO),1124 (BDS).
This is a long shot, but the PostCard does take a while longer to establish it’s first fix from a Cold Start. I normally won’t see a position until ~30 seconds, then I start the NTRIP Client afterwards. That way I know the GGA is available to send to the NTRIP Caster.
Just as some background, we’re using rtk2go to broadcast our NTRIP data. We have multiple other RTK Express devices that have no problem with getting the green dot through rtk2go.
Luciano and I are working together on the same project.
The LG290P is new to me, and much different than the F9P inside the Express.
That’s why I’m wondering if the messages from your Base might be involved with the LG290P not getting a RTK Fix.
I’m just guessing here
Your screenshots suggest that SWMaps doesn’t receive the necessary information from the receiver, so you likely don’t have all the necessary NMEA sentences coming from the receiver.
Your DOP values are less than 1.0, suggesting you have an RTK fix, but SWMaps can’t understand that from insufficient fix information.
I would guess you have $GPGSA on (it contains DOP data but no detailed fix data, just 2D/3D) and something like $GPRMC (that includes coordinates), but not $GPGST and $GPGGA.
SWMaps FAQ says:
SW Maps uses the NMEA GGA and RMC sentences for position and time, GSA and GSV sentences for skyplot display, and the GST sentence for accuracy.
Hi @bushman_K, we perhaps don’t fully understand. We are uploading from the Reference Station up to RTK2go, and then from RTK2go to the SW Maps devices. Our regular RTK Expresses get the green dot fine, while the postcards are not.
If we are getting the green dot and correction data for the RTK Expresses, would that mean all the data from RTK2go should also be sufficient for the Postcards?
Yes, you don’t seem to understand the logic of this process.
An RTK rover device (Postcard, in your case) receives correction data from an NTRIP caster (rtk2go) and calculates a precision solution based on that and whatever it receives with its GNSS antenna.
But having a precision solution calculated by your rover device and having your collector application (SW Maps) “realize” it’s a precision solution are two separate things.
In your case, Postcard seems to be able to calculate it just fine. But it doesn’t report it in a way so SW Maps would understand it.
So SW Maps correctly plays half of its role as an NTRIP client - connects to RTK2go, takes correction data, and sends it to Postcard.
But it can’t play another half of its role, displaying the precision solution status, because Postcard doesn’t send enough information back to SW Maps. It doesn’t mean you don’t have a precision solution, it means SW Maps doesn’t show it.
In case when you use RTK Express, it does send enough information back to SW Maps so it does “realize” it’s a precision solution.
RTK Express (U-blox F9P) and PostCard (Quectel LG290P) are 2 different animals.
As I mentioned, I’ve had no problems testing the LG290P with the following corrections:
The (3) standard Base Station messages: 1005, 1032, 1033
Plus the MSM4 messages: 1074 (GPS), 1094 (GAL),1084 (GLO),1124 (BDS).
I don’t think this issue has anything to do with what the caster supplies. OP should figure out what NMEA messages his rover receiver sends back to SW Maps (it definitely doesn’t send all the messages SW Maps wants to receive) instead of diverting his attention to corrections.
