Interfacing with Matlab through USB port of Mosaic-X5 Triband GNSS RTK Breakout

taho2192 · July 22, 2024, 8:02pm

I am trying to interface with Matlab as a serial port through the USB-C Port on the breakout board. However, no data is being transmitted through the serial port when connected to Matlab. Output from the USB-C works properly when connected to RxTools software, just not when connected to a third-party application like Matlab. I had a long discussion with Septentrio Support and they couldn’t help and said it must be a handshake issue between the port and Matlab. Has anyone had this issue before and/or is there a known way to fix it? Any ideas would be greatly appreciated.
Thanks!

PaulZC · July 29, 2024, 7:17am

Hi @taho2192 ,

It might be easier to connect to one of the UART COM ports instead using a “FTDI” cable or breakout board? Just make sure you have the cable / board configured for 3.3V.

If the COM port is unresponsive, you can send an “escape” sequence to wake it. From the firmware manual:

"
A connection that is not configured in CMD mode or auto mode will be blocked for user commands. There are two ways to re-enable the command input on a blocked connection. The first way is to reconfigure the connection by entering the command setDataInOut from another connection. The second way is to send the “escape sequence” consisting of a succession of ten “S” characters to the blocked connection within a time interval shorter than 5 seconds.
"

"
By default, all COM ports are set to a baud rate of 115200 baud, using 8 data-bits, no parity, 1 stop-bit and no flow control.
"

This Arduino code might help:

github.com

sparkfun/SparkFun_u-blox_PointPerfect_Library/blob/be02bf28a329018ec138b834c6db7101271a07b0/examples/Example3_mosaic-X5_L-Band/Example3_mosaic-X5_L-Band.ino#L288-L346


      
          bool sendWithResponse(const char *message, const char *reply, unsigned long timeout = 1000, unsigned long wait = 100); // Header
          bool sendWithResponse(const char *message, const char *reply, unsigned long timeout, unsigned long wait)
          {
            if (strlen(reply) == 0) // Reply can't be zero-length
              return false;
          
            if (strlen(message) > 0)
              serialGNSS.write(message, strlen(message)); // Send the message
          
            unsigned long startTime = millis();
            size_t replySeen = 0;
            bool keepGoing = true;
          
            while ((keepGoing) && (replySeen < strlen(reply))) // While not timed out and reply not seen
            {
              if (serialGNSS.available()) // If a char is available
              {
                uint8_t chr = serialGNSS.read(); // Read it
                if (chr == *(reply + replySeen)) // Is it a char from reply?
                  replySeen++;

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I hope this helps,
Paul

btreichel · August 1, 2024, 5:20am

Start by looking at this page. Serial and USB Communication - MATLAB & Simulink