Ublox gps on RS232

Technical Support
1

Hi Team,
I am using colibri imx8x module, BSP 6.x, doing test on ublox gps module on RS232 using ttl converter , I am not able to retirve the data from modem.
At the same GPS module is verified on the host side , it was fine.
can you give some inputs ? or if any of gps module is tested and verfied already please let me know, it will helpful.

Thanks,
Aadhuraj

2

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Hello,

To troubleshoot the issue with your u-blox GPS module not transmitting data to your Colibri iMX8X module via RS232 with a TTL converter, please follow these steps:

  1. Verify Hardware Connections: Ensure that the GPS module’s TX pin is correctly connected to the RX pin on the Colibri iMX8X and vice versa. The VCC and GND should also be correctly connected, matching the power requirements of the GPS module.

  2. Check Power Supply: Verify that the GPS module is receiving the correct voltage. Some GPS modules operate at 3.3V, while others may require 5V.

  3. Serial Port Configuration: On the Colibri iMX8X, you need to configure the serial port to match the baud rate and serial configuration (data bits, stop bits, parity) of the GPS module. u-blox modules typically use 9600 baud by default, but this can vary. You can use the stty command to configure the serial port settings. For example:

    stty -F /dev/ttyUSB0 9600 cs8 -cstopb -parenb

    Replace /dev/ttyUSB0 with the correct serial device for your setup.

  4. Verify Serial Device: Ensure you are using the correct serial device file. On Linux, serial devices are usually named /dev/ttyS0, /dev/ttyS1, etc., for onboard UARTs, or /dev/ttyUSB0, /dev/ttyUSB1, etc., for USB-to-serial converters. Check the kernel log with dmesg command after connecting the device to confirm the device name.

  5. Permissions: Make sure you have the necessary permissions to access the serial port. You might need to add your user to the dialout group or use sudo to access the port.

  6. Test with GPS Software: Use GPS software tools such as gpsd and gpsmon to test the connection to the GPS module. These tools can help in diagnosing communication issues and verifying that data is being received correctly.

  7. Check for Kernel Messages: Look for any relevant kernel messages using dmesg that might indicate a problem with the serial port or the connection to the GPS module.

If after following these steps you are still unable to retrieve data from the GPS module, it could be helpful to test with a known working GPS module or setup to rule out any hardware issues.

Please, also check if these links can help you solve your problem:

U-Boot | Toradex Developer Center.

4

I have tried above instruction, still not able to read the gps data.
can you help on this ?

5

Hi @Aadhu ,

By host side, I assume that you are talking about the GPS module.

Do you mean that the GPS modem is sending data to Colibri iMX8X but you are not able to receive it.
Let us know how you are trying to receive the response from the GPS modem, did you send any command to it?.
Also, what UART you have connected

6

Hi Sahil,

I tried with usb to ttl converter on the host side, it was fine,
In Colibri module, i am using TTL to RS232 converter as gps is based on TTL.
I suspect ttl to rs232 converter had issue, I tried to test the loopback on the converter it’s not happening, I will get the new one, let me test with that device and confirm.
have been using both ttyLP0 and ttyLP2,
Thaanks,
Aadhu