INF: txbuf alloc

[bretwitt]

Describe the bug

Using a ZED-F9P with the latest firmware available on the ublox website. Launching the drivers with the following configuration file leads to the error (shown after cfg)

ublox_gps_node:
  ros__parameters:
    debug: 0                    # Range 0-4 (0 means no debug statements will print)
    device: /dev/ttyACM0
    tmode3: 0
    config_on_startup: false
    uart1:
       baudrate: 38400

[ublox_gps_node-11] [INFO] [1724096281.438107458] [ublox_gps_node]: U-Blox: Opened serial port /dev/ttyACM0
[ublox_gps_node-11] [INFO] [1724096281.441598932] [ublox_gps_node]: EXT CORE 1.00 (0fa0ae), HW VER: 00190000
[ublox_gps_node-11] [INFO] [1724096281.450412981] [ublox_gps_node]: U-Blox Firmware Version: 9
[ublox_gps_node-11] [INFO] [1724096281.452508922] [ublox_gps_node]: U-Blox configured successfully.
[ublox_gps_node-11] [ERROR] [1724096282.244591241] [ublox_gps_node]: INF: txbuf alloc
[ublox_gps_node-11] [ERROR] [1724096283.243799671] [ublox_gps_node]: INF: txbuf alloc
[ublox_gps_node-11] [ERROR] [1724096284.243412818] [ublox_gps_node]: INF: txbuf alloc

(that last message continues indefinitely)

This error appeared seemingly overnight, have tried with multiple ZED-F9Ps on the same vehicle and getting the same error. Using UART1 for the driver and UART2 with a radio for RTK. Have tried multiple USB-C cables, works fine with U-Center. Please let me know if any more info is needed

[bnbhat]

Hi @bretwitt,

The issue you’re experiencing is due to the TX buffer being full. The F9P module is unable to transmit all the data because of the limitations of the UART line, as you can only send certain amount of data at baudrate 38400.

You can get more detailed information about the TX buffer using the UBX-MON-TXBUF or UBX-MON-COMMS messages in u-center.

To resolve this, you can either increase the baud rate to allow more data to pass through the UART line or lower the Navigation Solution Rate (so there’s less data to send).

Since you have config_on_startup: false, I'm unable to replicate this issue on my F9P module.

Let me know if you have any questions.