RTKCONV not generating .OBS


I'm attaching a M8T module to teensy 3.1 (arduino like board) via UART 1. It is configured to provide 

raw data measurements with GPS + GLONASS and save it to a file .ubx.

Everything is alright with the process of configuring the module with Arduino IDE. 

The problem comes when a run the .ubx file through rtkconv. I only get the .nav.

But I'm only interest  in the .obs.

Does anyone is having the same problem?

I get the E=275 error. Couldn't find a reference anywhere. 


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  • Thanks on reply Marina!

    In the meanwhile, I downloaded Demo5 version of RTKLib and everything passed well.

    Anyway I am not skilled enough to enter inside code nor to compile it by myself.

    God bless You Marina


  • Hi!! 

    I solved this by setting a loop in my code to collect GNSS data for one second.

    String dataStringGNSS = ""; //aux string to print on datalogger
    char inByte; //aux char 

    int start = millis(); // variable to count milli seconds

    while (millis() - start < 1000) // 1 second loop
                if(gpsSerial.available() > 0){

                      inByte = gpsSerial.read(); //UART reads byte by byte

                      dataStringGNSS = String(inByte); //typecast byte into string 

                      dataFileGNSS.print(dataStringGNSS); // saves on datalogger


  • Same problem like Marina had 3 years ago...

    RTKConv.exe doesn't bulit OBS file, while ConvBin.exe does it but regardless to entered start time it produces RINEX with wrong date: 2019/04/16 (tomorrow) instead 2019/04/09 (last tuesday when actual observations were taken)

    Btw. I'm working with DJI Phanton 4 RTK and during last few months everything has been passing well...

    Tnx. & if somebody is interested there are two files attached below: single flight file and VRS rinex in ZIP for PPK



  • Hi,

    You can try to use TEQC like this : teqc loggps1_3.ubx > loggps1_3.obs



    • Hi!

      Thanks for the tip. But apparently there's something else.

      I'm starting to wonder if Arduino IDE is not modifying the data somehow while it prints to the file. Or if the microprocessor is modifying the data as well. Putting in a format that neither Teqc or RTKLIB can understand.  'Cause if I collect the data using U-Center, my configuration works just fine and I can get the .obs from RTKLIB.


    • Hi,

      Which kind of ublox GNSS module are you using ?

      When you do "teqc loggps1_3.ubx > log.obs" what do you get into the file "log.obs" ? Nothing ?



    • M8T module.

      I get blank file...

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