I have searched the GNSS Module Forum for an answer to my issue and have not able to find a solution.
Base Station: Sparkfun RTK Postcard/Portability Shield with L1/L2/L5 active antenna.
ZED-F9P UART3 RTCM3 Telemetry baud rate of 57,600.
Rover 1: Sparkfun ZED-F9P RTK Receiver with .
Rover 2: Sparkfun LG290P RTK GNSS Breakout Module L1/L2 active antenna.
LG290P GNSS RTK Breakout Module FW: LG290P03AANR01A05S
The baud rate for the LG290P RTCM3 Telemetry UART3 input is 57,600.
I decided to evaluate my Sparkfun RTK Postcard/Portability Shield Base Station with the Sparkfun LG290P RTK GNSS Development Module that I plan to install on my Traxxas Rover.
I setup the RTK Postcard/Portability Shield Base Station in the driveway with a clear view of the sky, got a mean deviation of under 0.3 m after a 60 sec Survey-in, after which the RTCM3 transmissions began.
Then I powered up the Sparkfun ZED-F9P RTK Receiver that is presently on my Traxxas Rover, which had a clear view of the sky, and after less than five minutes I had a RTK Fix indication when the board RTK LED indicator quit flashing.
So I swapped out the ZED-F9P RTK Receiver with the Sparkfun LG290P RTK GNSS Breakout Module and could only get a RTK Float indication as the board RTK indicator LED kept flashing and never turned off to indicate a RTK Fix indication.
To verify this issue with the LG290P RTK GNSS Development Module, I took the LG290P RTK GNSS Development Module off the Traxxas Rover and hooked it up to a laptop outdoors and used the Quectel QGNSS app to verify that the LG290P RTK GNSS Development Module on the Rover was only getting a RTK Float indication, not a RTK Fix indication, and that was the case as the QGNSS Data View Quality Indicator was showing “Float RTK”.
Since my Sparkfun ZED-F9P RTK Receiver was able to reach a RTK Fix indication using the same Sparkfun RTK Postcard/Portability Shield Base Station I am confident that the same RTCM3 messages should be being received by the LG290P RTK GNSS Development Module too.
Therefore I am presently at a loss as to how to troubleshoot this issue as it looks like I have the latest stable LG290P software version according to the Sparkfun GitHub.
After doing a lot of IoT searching, its seems that the LG290P RTK GNSS Development Module requires RTCM3-MSM4 messages on the UART3 input to achieve a RTK Fix indication when in the Rover mode.
I believe that my Sparkfun RTK Postcard/Portability Shield Base Station is only outputting RTCM3 messages.
Is this revelation correct and if so how to configure my Sparkfun RTK Postcard/Portability Shield Base Station for RTCM3-MSM4 message output on UART3?
Further research indicates that the UART3 output of the LG290P can be configured directly for RTCM3-MSM4 output by sending the following Quectel NMEA commands to the LG290P:
The command $PQTMSETTING,W,MODE,1,0,3*6D puts the receiver into a mode where it will only output MSM4 and RTCMv3 1005 messages.
Save the new settings to the non-volatile memory by sending $PQTMSAVEPAR*5A.
Reboot the module by sending $PQTMSRR*4B.
On the other hand, I have tried using the RTK Everywhere serial user interface with PuTTY, but the “Configure GNSS Messages” Menu item only opens up a menu that allows “Set Base RTCM Messages” which allows the selection of available RTCM3 messages, but not the configuration of those messages.
Thanks for the additional response.
If the RTK Postcard UART3 output is both RTCM3-MSM4, why won’t the Sparkfun LG290P Development Module go into RTK Fix?
Hi All,
I am at a loss as to why the Sparkfun LG290P RTK GNSS Breakout Board on the Rover cannot reach a RTK Fix solution whereas my Sparkfun ZED-F9P RTK GNSS module, when receiving RTCM3 messages at 57600 baud from the same Sparkfun RTK Postcard, can reach a RTK Fix solution.
Using 115200 baud for both the Base Station and the Rover UART3 does not result in RTCM3 transmissions whereas using 57600 baud does and the Rover obtains a RTK Float, but never a RTK Fix.
Hi All,
The solution to my issue was to use a L1/L2/L5 active antenna instead of the the L1/L2 active antenna that had been working satisfactorily with the ZED-F9P RTK GNSS Receiver on the Rover and disabling the NMEA messages in the UART3 Radio output stream on the Sparkfun RTK Postcard.
The LG290P on the Rover will now display a solid white RTK LED indicating a RTK Fix solution when taken outdoors.
Regards,
TCIII