UART Communication Issue with Sparkfun Ublox SAM-M8Q

GPS/GNSS Development Boards
1

Hey,

I recently bought a Sparkfun Ublox SAM-M8Q and tried to use it with a RaspberryPi Zero and the Python library (https://github.com/sparkfun/Qwiic_Ublox_Gps_Py.git). However, I can not establish the UART communication to work.

I am using the example programs in the library to test the Module, but I don’t receive any data via UART. (gps.geo_coords() returns NONE )

I have checked the following:

  • wiring

  • The serial interface is active on the pi

  • serial communication is working with another device

    • I am out of ideas on what to check or how to get this to work, I would appreciate it if anybody has an idea how to solve this.

    2

    Hi,

    The SAM-M8Q defaults to 9600 Baud on its UART1 TX pin. Maybe that’s it? Modules like the ZED-F9R default to 38400.

    I hope this helps,

    Paul

    3

    Paul, you beat me to the reply!

    Here are some additional steps for getting more information about this issue:

    1. Can you try using Screen or Picocom on the Pi, see if the Pi is recognizing the serial connection, and if so, what is being transmitted on it?

    2. When you say, “serial communication is working with another device”, do you mean you tested the Pi serial with another device and it works, or you tested the M8Q serial with another device and it works?

    3. Also, if you have a 3.3v microcontroller available, hooking that up to the M8Q might be a good way to verify that the issue is not the Pi; I’ve had trouble with serial on the Pi before with tty settings and whatnot. A microcontroller is going to be a much simpler system to work with, bypassing some of the complexity of a full OS.

    4

    Thank you very much for the quick replies.

    I forgot to mention it earlier, but I played around with different Baud rates. It seemed to have no impact on the functionality and I stuck with 9600 Baud.

    The SAM-M8Q defaults to 9600 Baud on its UART1 TX pin

    I didn’t try that, I will check that out.

    Can you try using Screen or Picocom on the Pi, see if the Pi is recognizing the serial connection, and if so, what is being transmitted on it?

    I tested the Pi serial with another device, not the M8Q

    When you say, “serial communication is working with another device”, do you mean you tested the Pi serial with another device and it works, or you tested the M8Q serial with another device and it works?

    Definitely gonna try this, it didn’t come to my mind, that the problem could be the Pis serial interface even if it works with other devices.

    1. Also, if you have a 3.3v microcontroller available, hooking that up to the M8Q might be a good way to verify that the issue is not the Pi

    I will post an update on what worked and what didn’t.