Configure the Sparkfun LG290P RTK Receiver UART3 for 57k baud

GPS/GNSS
1

I have a Sparkfun LG290P RTK Receiver module that I am using as a Rover and would like to configure the UART3 input of the LG290P RTK Receiver module for 57K baud to match the baud rate of the telemetry radio receiving RTK correct data from my Sparkfun RTK Postcard Base Station.

I have connected the Sparkfun LG290P RTK Receiver module to the QGNSS app on my PC and can receive the NMEA data stream in the QGNSS Console window on the USB Enhanced Serial-A port. I have setup the Console Checksum for NMEA and the Suffix set to CRLF. Using the Console Tool I can stop the received NMEA messages using the (up arrow) button and only see transmitted NMEA messages (down arrow) button sent from the Data Input window.
As as test case, I have transmitted the PQMT message $PQTMVER*58 to see if I could receive the firmware version. So the question is, how am I supposed to see the received firmware version message if I have both the received and transmitted NMEA message buttons on. I know that the $PQTMVER*58 is being sent as I can see it in the Console window when the received NMEA message button (up arrow) is off and the transmitted NMEA message button (down arrow) is on. However, I can see no way to see the LG290P response to the $PQTMVER*58 NMEA firmware request message mixed in with the satellite NMEA messages from the LG290P in the Console window.

What am I doing wrong in the Console window to be able to see the LG290P response to the $PQTMVER*58 NMEA firmware request message? Should I be on the USB Enhanced Serial-B port and not the USB Enhanced Serial-A port to configure UART3 using the QGNSS app Console?

Regards,

TCIII

2

Here a valid explanation:

link

Qgnss 2.2 latest link on mega because en_official do not work but cn_ https://www.quectel.com.cn/wp-content/uploads/2025/02/QGNSS-V2.2_CN.zip do if registered.

so for 57600 baud …

stop gnss engine for see only commands_debug

$PQTMGNSSSTOP*09

resp. $PQTMGNSSSTOP,OK*21

$PQTMCFGUART,W,3,57600*34 set uart3
resp. $PQTMCFGUART,OK*60

$PQTMCFGUART,R,3*29 ask&get
response $PQTMCFGUART,OK,3,57600,8,0,1,0*6E

save $PQTMSAVEPAR*5A

reboot $PQTMSRR*4B

for default all three uarts accept rtcm in & out + nmea

see $PQTMCFGPROT at 2.3.12

and for baud_setting in official doc!?:

immagine
immagine617×164 6.17 KB

3

@bamarcant

Thanks for the quick response, much appreciated.

Question: Should I be on USB Enhanced Serial-A or Serial-B to change the UART3 baud rate?

The IoT says that USB Enhanced Serial-B should be used for configuration changes.

Regards,

TCIII

4

Of course,Paul explained well: LG290P UART1 is connected to the CH342 USB interface chip on its channel B. for direct debug purpose…

ch A is for esp32 who contains pygps interface program.

1 Like
5

@bamarcant

Ran the PQTM sequence using QGNSS v 2.2 on USB Enhanced Serial-A and UART3 is now set to 56.7k baud.

Thanks for your help, much appreciated.

Regards,

TCIII

1 Like