LG290P - still garbage data / no PQTM replies even after trying every baud rate

[Michael_Boeding]

What I’m seeing

• Connected via USB-C (CH342) and directly to an ESP32-S3 (TX1/RX1 pins).
• Set port to 8-N-1, tried every standard baud from 9 600 → 921 600, including the spec’d 460 800 bps.
• No matter the rate:
  • Port B (UART1?) = silent.
  • Port A (UART3?) and ESP32 link = endless repeating pattern
    80 00 78 80 78 80 78 … (0x78/0x80/0xF8/0x00).
  • $PQTMVERNO*58<CR><LF> always times out.

What I already verified

• TX/RX crossover & common ground OK (swapping silences output).
• Added explicit CR+LF after every command.
• Tried $PQTMDEBUGOFF*06 and blindly sent CFGPROT/CFGUART strings—no ACK.
• 3 V3 rail stable; same antenna works on other receivers.

[Michael_Boeding]

To add to this I also tired to use the QGNSS through the USB-C (UART1) and the only data im getting is this which seems to be garbage also…could I have a bad board?

[bamarcant]

Did U try to flash the fw?
But use Qgnss 2.1
https://www.quectel.com/content/uploads/2024/07/QGNSS_V2.1_EN.zip
then complete upgrade on esp…

[JanW]

How to connect to the module is described here Interface w/ LG290P - SparkFun RTK Postcard Hookup Guide in the Connecting to the LG290P section.

If the connection is successful, you can try to restore factory settings:

Restore settings to factory defaults
$ PQTMRESTOREPAR*13

If there are no errors, you will receive the foloowing response:
$PQTMRESTOREPAR,OK*3B

To see satellites in QGNSS the antenna must be outside the window.

[Michael_Boeding]

@bamarcant

fw?

Switched to the latest version of QGNSS and flashed it with the latest firmware and it all just works now…super weird. So maybe just bad firmware?

[Michael_Boeding]

I also now have it working while connected to my esp32s3…but feeding 3.3v from the esp32s3 to the BlueSMiRF did not work - I had to feed 5v from the esp32s3 to the 5v on the board before it would start actually exporting the full sentences over UART 2