Warning PX4 disconnected from UART



  • Hi all,
    I am getting this message on my Voxl flight deck
    Warning PX4 disconnected from UART.
    I had this issue yesterday as well, I thought it might be a cable issue but everything was fine. So I reset my flight core and set it up again and uploaded this parameter file from GitHub parameter
    The error then went away yesterday. But today again i got this error message.I checked this Post and my parameters are the same. I again uploaded the GitHub parameters like before but no luck.

    yocto:~$ voxl-vision-px4 -d
    loading our own config file
    =================================================================
    Parameters as loaded from config file:
    qgc_ip:                     192.168.1.114
    en_localhost_mavlink_udp    1
    en_secondary_qgc:           0
    secondary_qgc_ip:           192.168.1.214
    qgc_udp_port_number:        14550
    localhost_udp_port_number:  14551
    udp_mtu:                    512
    en_vio:                     1
    en_voa:                     1
    en_send_vio_to_qgc:         1
    en_send_voa_to_qgc:         1
    en_set_clock_from_gps:      1
    en_force_onboard_mav1_mode: 1
    en_reset_px4_on_error:      1
    qvio_auto_reset_quality:    0.000500
    en_adsb:                    0
    adsb_uart_bus:              7
    adsb_uart_baudrate:         57600
    px4_uart_bus:               5
    px4_uart_baudrate:          921600
    offboard_mode:              off
    follow_tag_id:              0
    en_tag_fixed_frame:         0
    fixed_frame_filter_len:     5
    en_transform_mavlink_pos_setpoints_from_fixed_frame:0
    =================================================================
    loading extrinsics config file
    starting geometry module
    starting px4 monitor
    starting uart mavlink
    Successfully opened mavparser
    starting udp mavlink
    Adding manual QGC IP address to udp connection list: 192.168.1.114
    Added new UDP connection to 192.168.1.114
    starting px4 shell
    starting fixed pose input
    starting vio manager
    starting tag manager
    starting voa manager
    Init complete, entering main loop
    Connected to voxl-qvio-server
    done updating transforms to use imu: imu0
    WARNING PX4 DISCONNECTED FROM UART
    

    Thanks & Regards,
    Mohammed Naveed


  • Dev Team

    Hi @mohammednaveed ,

    Sorry for the lag, is this still showing up as an issue?

    One way I try to trouble shoot the MAVLink connection over the UART from the VOXL processor(s) to Flight Core STM32 is using: https://docs.modalai.com/voxl-vision-px4-nuttx-shell/#interactive-mode

    From the other side, if you can open a MAVLink connection over USB to the Flight Core, and run mavlink status from the nutshell, to see if you have any active traffic?



  • Hi @modaltb
    Its alright!
    It still shows up randomly, will try your suggested method and get back soon!

    Thanks & Regards,
    Mohammed Naveed



  • Hi @modaltb
    I checked it today, the issue still exists!
    I followed your instructions and have attached the following messages. This is only happening on this Voxl flight deck unit, my other unit is working perfectly.

    Voxl FD unit 2.png

    loading our own config file
    =================================================================
    Parameters as loaded from config file:
    qgc_ip:                     192.168.1.114
    en_localhost_mavlink_udp    1
    en_secondary_qgc:           0
    secondary_qgc_ip:           192.168.1.214
    qgc_udp_port_number:        14550
    localhost_udp_port_number:  14551
    udp_mtu:                    512
    en_vio:                     1
    en_voa:                     1
    en_send_vio_to_qgc:         1
    en_send_voa_to_qgc:         1
    en_set_clock_from_gps:      1
    en_force_onboard_mav1_mode: 1
    en_reset_px4_on_error:      1
    qvio_auto_reset_quality:    0.000500
    en_adsb:                    0
    adsb_uart_bus:              7
    adsb_uart_baudrate:         57600
    px4_uart_bus:               5
    px4_uart_baudrate:          921600
    offboard_mode:              off
    follow_tag_id:              0
    en_tag_fixed_frame:         0
    fixed_frame_filter_len:     5
    en_transform_mavlink_pos_setpoints_from_fixed_frame:0
    =================================================================
    loading extrinsics config file
    starting geometry module
    starting px4 monitor
    starting uart mavlink
    Successfully opened mavparser
    uart send msgid:   0 sysid:  0 compid:197
    starting udp mavlink
    Adding manual QGC IP address to udp connection list: 192.168.1.114
    Added new UDP connection to 192.168.1.114
    starting px4 shell
    starting fixed pose input
    starting vio manager
    starting tag manager
    starting voa manager
    Init complete, entering main loop
    Connected to voxl-qvio-server
    done updating transforms to use imu: imu0
    uart send msgid:   0 sysid:255 compid:190
    uart send msgid:   0 sysid:255 compid:190
    WARNING PX4 DISCONNECTED FROM UART
    uart send msgid:   0 sysid:255 compid:190
    uart send msgid:   0 sysid:255 compid:190
    ^C
    received SIGINT Ctrl-C
    Starting shutdown sequence
    Stopping adsb
    stopping voa manager
    stopping tag manager
    stopping vio manager
    stopping fixed pose in module
    stopping px4 shell module
    Stopping udp mavlink module
    exiting QGC udp listener thread
    exiting localhost udp listener thread
    udp_mavlink stopped
    Stopping uart mavlink module
    waiting for uart reader thread to join
    waiting for SDSP mavparser to close
    Stopping px4 monitor
    closing remaining client pipes
    closing remaining server pipes
    Removing PID file
    exiting
    


  • Is there a possibility that my VOXL board is bricked? Since the issue hasn't been resolved.


  • Dev Team

    Hi @mohammednaveed ,

    The screen shot from QGC is of the unit with the issue? I'm a little confused as it shows a connection here which is that connecting to the VOXL:
    81cc0fab-fb77-4ee9-9971-2e9c16dff534-image.png

    If you can adb into the VOXL side and also get a MAVLink connection over USB to the Flight Core side, I'd say no it's not bricked.

    I'm wondering if we are missing something else. Are you modifying the PX4 FW or software on VOXL at all?

    What else are you running if anything on VOXL?

    There's a physical UART connecting the two, there are discrete components on the board such as ESD diodes, is the hardware being altered or installed into anything or just used in a Flight Deck? It's sounding like software and maybe an edge case with timing if it's intermittent though... if hardware issue it wouldn't work at all..



  • Hi @modaltb
    No I can ADB into the voxl, so its not bricked!
    This board is brand new and we were just configuring the flight core and we had just updated the custom firmware from v0.0.5 to v0.2.3.
    We just wanted to do VOA.
    However we found the issue, it seems to be a hardware issue!
    The J12 port to which the TELEM cable is connected to is not working correctly. I physically inspected if there are any damages but couldnt find anything wrong.
    This voxl was not able to communicate with another flight core as well. But once we shifted to J10 port it started to work correctly.
    So is it still hardware issue?

    Thanks & Regards,
    Mohammed Naveed


  • Dev Team

    Hi @mohammednaveed ,

    AH ok I thought you had a VOXL-Flight, but it sounds like you have a VOXL and an external flight controller?

    J12 is on the VOXL:
    78be1d65-234a-4d8f-a75b-96183974115f-image.png

    On VOXL-Flight, it's internally routed.

    OK, we have a loop back test that you can use to test the hardware on J12.

    If you can connect pins 2/3 together via a custom cable, you can try the loop back test to see if the HW is OK: https://gitlab.com/voxl-public/core-libs/libvoxl_io/-/blob/master/lib/apps/voxl-uart-loopback.c#L54



  • Hi @modaltb
    Sorry if i didnt mention this earlier. Its a VOXL flight deck which is having this issue. My other VOXL flight deck is working fine and we tried to interchange the board and see where the issue was and found out to be the J12 port. In the other flight deck J12 is working correctly.
    I'll try the loop back test.

    Thanks & Regards,
    Mohammed Naveed


Log in to reply