u-blox Firmware Update

The u-blox receiver's firmware is separate from the ARK module's CAN node firmware, and is updated with u-blox's u-center desktop tools — u-center for the ZED-F9P, u-center 2 for the ZED-X20P. The procedure applies to the ARK RTK GPS, ARK RTK Base, and ARK X20 RTK GPS.

Connecting

• ARK RTK Base — connect over USB-C. The F9P enumerates directly as a USB serial port.

• CAN modules (ARK RTK GPS, ARK X20 RTK GPS) — hold the safety switch while powering the module through a CAN port, until all three LEDs blink rapidly. This bridges the receiver's UART1 to the debug connector's UART (pins 2/3 of the 6-pin JST-SH, plus GND). Attach a 3.3V USB-serial adapter there and connect u-center to that COM port. Check Use this baudrate for update and select 115200. See the PX4 ARK RTK GPS page for the full procedure.

u-blox firmware cannot be updated over UART2. GPS_UBX_MODE 7 opens UART2 as a UBX diagnostic port for u-center, but firmware update is only available on UART1 via the debug passthrough above.

Updating

1. Check the installed version: in u-center open View > Messages View > UBX > MON > VER; u-center 2 shows the firmware version on the device page.

2. Download the firmware image from the u-blox product page — ZED-F9P or ZED-X20P, under Documentation & resources.

3. Run the firmware update tool (Tools > Firmware Update in u-center, Firmware Update on the device page in u-center 2), select the downloaded image, and leave the remaining settings at their defaults.

4. When the update completes, power cycle the module and re-check the version.

Do not power cycle the module while the update is running.