3.3 KiB
u-blox Diagnostics with u-center
u-center is u-blox's desktop tool for monitoring a receiver's live satellite, signal, and position data, and for reading and writing its configuration.
Setting GPS_UBX_MODE to 7 configures a u-blox receiver's UART2 as a UBX diagnostic port for u-center, while the receiver continues to serve the autopilot on UART1 (as usual).
This is useful for diagnosing poor fixes, interference, or RTK issues without disconnecting the autopilot.
:::info Heading and static-base-on-UART2 setups cannot use this feature. For more information see Constraints below. :::
布线
Connect the adapter's RX to the receiver's UART2 TX, its TX to UART2 RX, and share ground.
u-blox UART pins are 3.3 V.
PX4 配置
The parameters to set:
| Parameter | 设置 |
|---|---|
| GPS_UBX_MODE | u-center on UART2 (7) |
| GPS_UBX_BAUD2 | UART2 baudrate, must match the USB-serial adapter (default 230400) |
Both parameters take effect after a reboot.
Messages Enabled on UART2
The following messages are enabled when GPS_UBX_MODE is set to 7:
| 消息 | 频率 |
|---|---|
NAV-PVT, NAV-DOP, NAV-STATUS, MON-RF |
Every navigation epoch |
NAV-HPPOSLLH |
Every epoch, except M9 |
RXM-RTCM |
Every epoch, M9 and F9P |
NAV-SAT |
Every 10th epoch |
The set runs around 300 bytes per navigation epoch (GPS update cycle), roughly triple that on the epoch carrying NAV-SAT.
The default UART2 baud rate (230400) covers the 25 Hz maximum; 115200 is the practical floor at the 10 Hz default rate.
Below that, the NAV-SAT epoch saturates the link, and a u-blox receiver drops messages on a congested port rather than throttling: the result is gaps in u-center.
约束
- UBX input is enabled on
UART2, so anything connected there can reconfigure the receiver. Use this on the bench, not in flight. - The driver writes to the receiver's RAM configuration layer on every boot. Changes made from u-center to the RAM layer are lost at the next power cycle; changes written to BBR or flash persist and will fight the driver.
GPS_UBX_MODE1, 2 and 5 useUART2for RTCM, so heading and static-base-on-UART2 setups cannot use mode 7.- The mode is skipped with a warning on M10 and F10 receivers, and on receivers older than u-blox protocol version 27.