The u-blox GPS has not accepted one of ArduPilot's settings

What ArduPilot says:

• GPS N: u-blox … configuration 0x0x…

ArduPilot configures a u-blox receiver step by step and ticks a step off when the receiver confirms it. This line names the first step still open (“solution rate”, “GNSS settings”, “SBAS settings”, “navigation settings”, “TIM TM2” and so on) and gives all open steps as one hexadecimal number. Right after power-on that is normal. If it stays, the receiver is refusing that setting, or is not hearing the flight controller.

What to do, most likely first

1. The receiver is still being configured.

   FixWait half a minute and try to arm again.

2. The module is a clone or an older generation and does not support the setting.

   CheckThe start-up line “u-blox … HW: … SW: …” shows what the module says it is. The open step stays the same however long you wait.

   FixFor “GNSS settings”, set GPS1_GNSS_MODE (GPS2_GNSS_MODE for the second GPS) to 0: the module then keeps its own choice of satellite systems and the step is ticked off. A module that refuses other steps is best replaced with a genuine one.

3. A setting of your own asks for something this module cannot do: a rate above 5 Hz (“navigation rate”), raw data (“raw rate”) or an SBAS choice (“SBAS settings”).

   CheckGPS1_RATE_MS is below 200, GPS_RAW_DATA is not 0, or GPS_SBAS_MODE is not 2.

   FixPut them back to their defaults (GPS1_RATE_MS 200, GPS_RAW_DATA 0, GPS_SBAS_MODE 2) and reboot.

Parameters to look at

Where to do it:Setup & Tuning Guide