LG290P BB + BlueSMiRF v2 - Issues with GST sentences not showing up through Bluetooth

Hello, i am creating this topic hoping to find someone that can give me ideas to solve an absurd problem that occured to me after solving multiple issues with my LG90P breakout board in conjonction with a BleSMiRF v2.

When i bought my units a few months ago, with the intent to use them with my phone and both SWmaps and Qfield for general purpose on survey projects (forestry/archeology), i already had (predictable) issues with device recognition, wich i easily solved by adjusting the output baudrate of my bluetooth device to the by default one of the LG290P (460800 b/s) through a serial terminal. I updated the LG290P with the latest firmware thanks to Quectel QGNSS, operation that solved both the absence of GST sentences to receive error estimation, and the “not enough decimal printed” problem to show error values under a centimeter. After that, my devices worked perfectly, exept for one thing: when connected through BT error estimation, wether vertical or horizontal, was not functional (Fig.1).

Fig.1

So i hooked a USB/serial and BT/serial terminal on my phone to check on the output of my devices. To my surprise, although i had GST messages flowing through my USB/serial terminal (Fig.2), it was not the case for the BT/serial terminal (Fig.3).

Fig.2

Fig.3

To be sure there was no problem with the hardware i checked all i could, and remade the soldering of the header for the BlueSMiRF on the breakout board, with flux this time, ensuring there was no potential shortage between Rx and Tx.

And there i am, with data sent (presumably) from the GNSS chip directly to the reception port of my BT device, where a bunch the infomations carried by the signal is lost in the process. I have absolutly no idea on what cause the issue and i have next to no experience in this field to further tinker .

If you’ve encoutered a similar situation or have a lead on that matter, i’d be glad to hear what you can tell me.

Thank you for the read, have a good evening.

Welcome defacil! Luckily, I believe this is a known issue. tldr, update the firmware on the LG290P.

Original post. RTK Everywhere issue has some additional info.

Thank you for your answer and sorry for the late response.
I have done the firmware update for the LG290P (Beta 0224), the latest to my knowledge released by Quectel in last february. It didn’t fix my problem. I think the issue is different than the one you pointed to.
I have enabled GST messages in QGNSS with $PQTMCFGMSGRATE,W,GST,1*, as well as saved the changes and reboot. And indeed i have those messages showing up when the BB is connected through USBC. However, when connecting the bluetooth module to any of the Rx/Tx on the BB, the output is always the same. Even if i disable GGA messages on QGNSS for instance, they are still showing up on my bluetooth terminal.

You need to indicate on which uart activate…
LG290P has three uart, one for the usb the other on opposite sides.


$PQTMCFGMSGRATE,W,GST,1,2*15

AH !

A thousand thanks for this solution. It worked !!

I don’t know where you found this documentation, the one i found (wich is what’s available on Quectel website) that describe this $PQTM command (Fig. 1) for the LG290P does not specify the arguments i see in your image. Maybe its has been updated since the multiple new firmwares from early 2025, or have you taken it from another Quectel’s module manual ? Since i didn’t manage to find a general list of $PQTM commands i thought it was specific or partly specific to each individual module.

Anyway, thanks you again. have a good evening.

Fig.1

Here:

Regards

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