If you are using the Cubepilot flight controller, you can select the DroneCAN version or the UART 6-pin version. The CAN version will be connected to the CAN1 or CAN2 port, and the UART 6-pin can be connected to the GPS2 port.

UART 6 Pin version

If using the UART 6-pin version with Cubepilot flight controller and Ardupilot, set Serial3_Protocol to -1 so that Ardupilot will read the GPS2 port for GPS data if there is nothing connected on the GPS1 port.

The H-RTK ZED-F9P Rover features the u-blox ZED-F9P GNSS receiver, RM3100 Compass, and a tri-colored LED indicator, providing precise positioning and orientation data. It also boasts an IP66 rating, offering robust protection against dust and water, making it suitable for challenging environments.

This RTK GPS offers multi-band RTK capabilities with rapid convergence times and consistent performance. It supports concurrent reception of GPS (L1 & L2), GLONASS, Galileo, and BeiDou signals, ensuring reliable and precise positioning. This RTK GPS delivers centimeter-level accuracy with the use of a base station or NTRIP service. Additionally, there is also a DroneCAN option that offers MCU, IMU, barometer, and robust communication and integration for advanced UAV systems.

The high-precision PNI RM3100 compass ensures accurate orientation and stability, offering exceptional reliability, making it ideal for demanding UAV applications. It provides high resolution, low power consumption, large signal noise immunity, a large dynamic range, and high sampling rates. Its measurements are stable over temperature and inherently free from offset drift.

Features

• Advanced GNSS Receiver: Equipped with the high precision u-blox ZED-F9P GNSS receiver.

• Integrated RM3100 Compass: Accurate orientation accuracy and stability.

• High-Gain Antenna: Integrated large multi-band stacked patch antenna for enhanced signal reception across multiple GNSS frequencies.

• Durable Design: IP66-rated for protection against dust and water, suitable for harsh environments.

Options

Specification

With the newest firmware released by u-blox (v1.5x), all u-blox ZED-F9P now support the Galileo OSNMA feature.

Firmware version 1.51 can be downloaded from the link below, for the latest firmware please visit u-blox's official website.

For tutorials on how to update u-blox firmware on the H-RTK

For more information on enabling the OSNMA feature, please refer to the u-blox Integration Manual:

You can also find a installation guide made by community members:

UART 10 Pin GPS Port

U-blox F9P Chip Firmware Update

This step is optional but recommend for the optimum performance of your new Holybro GPS products. To update the u-blox firmware on your RTK units, you will need to download and use the free u-Center software.

To download u-Center, please go to u-blox's then follow the prompts to install the U-Center software onto your computer. During installation, you will be prompted to install a windows driver. On newer u-center, select "Use Windows USB Serial Driver". On the older version it will ask which driver you want to install, make sure ‘Standard Driver for Windows’ is checked.

Download the u-blox chip firmware from . (The latest firmware for u-blox F9P chip is v1.13.2 at the time of this guide).

Scroll down to firmware update and download the latest firmware: (ex. UBX_F9_100_HPG132.df73486d99374142f3aabf79b7178f48.bin)

Updating the Firmware

Connecting to U-Center

F9P Helical

When upgrading the F9P Helical module, just connect the module to the USB port of the computer via a USB-TYPE-C cable, as shown in the figure below:

F9P Rover

UART Version: To connect the Rover module (UART) to your computer, you need to connect the module to a USB-UART board, and the board is then connected to the computer. As shown in the figure below:

DroneCAN Version: For Ardupilot, you can follow the direction here:

Another way to connect the DroneCAN-F9P Rover to you computer is to open the case, and use a special USB adapter cable to connect the Rover module to the computer's USB port.

Uploading Firmware to U-Center

Open the U-center software, click the connect button (in the red circle in the figure below), and select the corresponding port.

Click tools-> Firmware Update, Firmware image to select the previously downloaded firmware: UBX_F9_100_HPG132.df73486d99374142f3aabf79b7178f48.bin, and then check the corresponding options in the figure below:

Click the GO button and wait for the firmware flashing to complete. Flashing generally only takes less than a minute. If the burning is successful, the upgrade interface will be displayed in green; if the upgrade is terminated, the interface will be displayed in red. If the programming process is interrupted, or if the time does not respond, it needs to be powered on again, and flash once according to the instruction.

Checking the current Firmware Version on the Module

With the Ground station/mobile station connected to U-center, click the view option, and enter View -> UBX-> MON -> VER.

As you can see from the arrow in the figure above, the firmware has been upgraded to 1.3.2.

Resetting U-Center Config

If you run into issue after some U-Center Configuration, you can always reset the config via the following command.

DroneCAN MCU Firmware Upgrade

Please use Mission Planner 1.3.74 or higher. Close the parameter setting page, click “Menu>Update” to check available updates. Update the DroneCAN MCU firmware. After clicking “Update”, it will ask whether to search for updates from the Internet. Click “Yes”. (Automatically searches for upgrades to the latest stable version firmware).

If “No update available” appears when searching updates. You can try to turn off your firewall in the system setting and try again.

Alternatively, If you have already downloaded the firmware on your local computer from (name of firmware folder is “HolybroG4-GPS” , and file to download is “AP_Periph.bin”) , Click “No” and you will be presented with a selection dialog box and then select the firmware file from your local drive.

After the upgrade, check whether the version is successfully upgraded.

H-RTK ZED-F9P Rover (all versions)

PX4 Guide for RTK

Ardupilot Wiki for RTK

Change Log

Getting started

In this section of the manual, we will cover the basic setup of the units. To setup the RTK units with Ardupilot, you will need Mission Planner installed on your computer or Ground Control Station and Ardupilot installed on your flight controller.

If you are using PX4 firmware and QGroundControl ground station software, please refer to the link for more information: https://docs.px4.io/en/advanced_features/rtk-gps.html Using RTK (Real Time Kinematics) greatly increases the accuracy of the GPS positioning. RTK mode requires a base station and a rover station. Either Rover or Helical can be use a rover station. The Helical or the "Base" model, we recommend using the "Base" model should be used as base station since it allows a larger external antenna.

Preparation

To use the H-RTK on a drone, you need the following hardware:

• A flight controller with CAN port for the GPS, a free serial port for the radio telemetry. A Holybro Pixhawk 4 or newer is recommended. This example uses a Pixhawk 6C.

• A pair of radio telemetry radios for data transmission, this example uses Holybro Sik Telemetry Radio V3

• A H-RTK Rover or Helical (UAV side)

• A H-RTK Helical or Base Station H-RTK F9P (base station side)

Connection Diagram

Connect the devices as follow:

Compass Setting

There is a compass on the GPS Module. After the flight controller connects and recognizes the GPS, you can see that a BusType of UAVCAN or I2C has been added on the SETUP -> Mandatory Hardware -> Compass page. If the priority of this external compass is not 1, you should click the icon on the page and set it to be the highest priority compass.

Compass Calibration:

Select the compass you want to use (the default is normally fine). Then click "Start" to begin calibrating the compass, follow the process until the calibration is done.

Ardupilot Parameter Setup

For flight controllers using Ardupilot Firmware

Using one GPS：

Connect the cable connector to the flight controller.

1.) Power the flight controller and connect it to Mission Planner. Go to "CONFIG > Full Parameter List" and modify the following parameters:

If connecting to the CAN1 port:

• : 1 (set virtual driver of CAN1 to DRONECAN)

• : 1 (set this parameter to enable CAN 1 bus)

if connecting to the CAN2 port:

• : 1 (set virtual driver of CAN 2 to DRONECAN)

• : 1 (set this parameter to enable CAN 2 bus)

2.) Set the following if you are using the DroneCAN version:

• : 9 (set the communication protocol type of GPS 1 to DroneCAN)

• : 231 (set to DroneCAN for the integrated LED’s type)

3.) On the RM3100 version, there is no external safety switch on the GPS unit, so ensure that (BRD_SAFETY_ENABLE on earlier ArduPilot versions) to 0 to disable the safety switch, or connect a external safety switch to the flight controller.

4.) Click "Write Params" when done. CAN functions will be available after rebooting the flight controller.

Using two GPS (Blending or Moving Baseline)：

Refer to the Ardupilot guide for the latest information

Two GPS may be used at the same time on a flight controller to either provide redundancy/blending, or moving baseline yaw.

If you are using DroneCAN version, make sure the firmware used for flight controller is ArduCopter 4.1.5 or higher, which automatically allocates 2 node IDs for DroneCAN. Older firmware might not be able to automatically allocate 2 node IDs.

To use two GPS on one flight controller at the same time, in addition to setting the parameters above, the following operations must be performed:

1.) Connect one GPS to the flight controller. If you are using the DroneCAN version, connect one to the CAN1 port and another to the CAN2 port.

2.) Power up the flight controller and connect to Mission Planner. Go to "CONFIG > Full Parameter List" and modify the following parameters:

• : set to 9 (If the communication protocol type of GPS 2 is DroneCAN)

• :set to 1 (If the communication protocol type of GPS 2 is UART)

To set up dual GPS Blending or GPS priority:

• : 2 for blending, 1 to usethe best GPS (self-judged)

• : bitmask for which elements are blended between the two GPS: bit 0, Horizontal Position, bit 1, Vertical Position, bit 2, Speed. A value of 7 (first three bits set) is suggested.

To set up Moving Baseline for Yaw:

Refer to the Ardupilot guide for the latest information

RTK Survey by Mission Planner

Base Module Setting using Mission Planner

Start with a base station setup first. During the base station setup, the rover and the UAV do not need to be turned on.

Open the Mission Planner ground station software on your computer and go to the "SETUP→ Optional Hardware → RTK/GPS Inject". You will see the following page:

Select the correct COM port that the base RTK module is connected to in the top right corner and click connect. In the SurveyIn Acc section, enter the absolute geographic accuracy that you expect your base station to achieve (2m or better is typical). In the Time column, enter the minimum survey time you expect (60sec or longer is typical). Click on Restart, the ground station will transfer the data you have entered to the base module, the base module will start a new round of surveying. You will see the following page:

During the survey process, the right box will show the current survey status:

• The Position is invalid: The base station has not yet reached a valid location.

• In Progress: The survey is still in progress.

• Duration: The number of seconds that the current surveying task has been executed.

The Green bar at the lower part of the Mission Planner page shows the current satellites being detected and the signal strength related to each satellite. At least eight or more satellite signals need to be guaranteed to exceed the red line (Only when the satellite signal exceeds the red line is the effective number of satellites).

The base station needs a certain amount of time to meet the accuracy requirements of your input. Testing shows that in an open area without shelter, to achieve the absolute accuracy of 2m takes a few minutes; to reach the absolute accuracy of less than 30cm takes around an hour; to reach the accuracy of 1cm takes around 24 hours.

Even if the accuracy of the base station is 1.5 to 2 m, the position accuracy of the rover module relative to the base station can still reach the centimeter level.

After the survey is complete, the Mission Planner will display the following page:

In the RTCM box it shows that the base status indicator is green, and the GPS/Glonas/BeiDou/Galileo satellite systems are all green. The Survey In box on the right says, Position is valid.

To store the current location in the Mission Planner: Click Save Current Pos, enter a name in the dialogue box, and click "OK". As shown below, you can see your saved location in the list. Click the Use button for the location you saved. The base station will enter the fixed mode and the status will show "Using FixedLLA".

In the future, if you set the base station in the same location, you do not need to conduct the survey again, just click the "Use" button that corresponds to the location you have saved.

Rover Module and Flight Controller Setup

After the base station is set up, you can turn on the UAV. The base station data will be transmitted through the telemetry module to the GPS module on the UAV. In the Mission Planner main page, you can see the current GPS status displayed as RTK Float / RTK Fixed / 3D RTK, indicating that the positioning of the UAV has entered RTK mode.

• RTK Float is a floating-point solution。

• RTK Fixed is a fixed solution. RTK Fixed mode has higher accuracy and requires better signal strength.

• 3D RTK is unified saying of RTK Float / RTK in the Mission Planner Chinese version

Mission Planner Software Configuration of F9P Parameters (DroneCAN Version)

Parameters change

To change the internal parameters of the F9P module through Mission Planner, connect to the controller normally and go to the SETUP->Optional Hardware->DroneCAN/UAVCAN screen. Press the MAVLink CAN1 (or MAVLink CAN2 If on the CAN port 2) button, and you will see the GPS by name:

Press the “Menu” button and then click "Parameters" from the right drop down menu.

In the parameter setting page, you can see all the parameters of F9P. If you change something, click "Commit Params" to save the changes。

Getting started

In this section of the manual, we will cover the basic setup of the units. To setup the RTK units with PX4, you will need QGroundControl installed on your computer or Ground Control Station and PX4 installed on your flight controller. If you are using Ardupilot firmware and Mission Planner ground station software, please refer the Ardupilot setup guide. Using RTK (Real Time Kinematics) greatly increases the accuracy of the GPS positioning. RTK mode requires a base station and a rover station. Either Rover or Helical can be use a rover station. The Helical or the "Base" model, we recommend using the "Base" model should be used as base station since it allows a larger external antenna.

Preparation

To use the H-RTK on a drone, you need the following hardware:

• A flight controller with CAN port for the GPS, a free serial port for the radio telemetry. A Holybro Pixhawk 4 or newer is recommended. This example uses a Pixhawk 6C.

• A pair of radio telemetry radios for data transmission, this example uses Holybro Sik Telemetry Radio V3

• A H-RTK Rover or Helical (UAV side)

• A H-RTK Helical or Base Station H-RTK F9P (base station side)

Connection Diagram

Connect the devices as follow:

Flight controller Setting with PX4 Firmware

If you are using DroneCAN version, make sure The firmware used for flight control is PX4 V1.12.3 or higher, which automatically allocate 2 node ID for DroneCAN. Older firmware might not be able to automatically allocate 2 node ID. You will need to use newer firmware and perform following operation to manually assigning node ID. Connect the GPS to the flight controller.

If you are using DroneCAN version, connect the flight controller to QGC and Make sure the parameter has been set to "Sensor Automatic Config". The DroneCAN-F9P will now work.

RTK GPS settings

The RTK GPS settings are specified in the QGroundControl (Settings View > General Settings > RTK GPS).

These settings define the minimum duration and minimum accuracy for completing the RTK GPS setup process (known as "Survey-In").

Flight Controller Setup

The parameter needs to be set to Enabled.

MAVLink2

The MAVLink2 protocol must be used because it makes more efficient use of lower-bandwidth channels. This should be enabled by default on recent builds. Holybro SiK Telemetry Radio uses MAVLink2 protocol by default. But if you are not sure about the status of the data transmission, you can go through the following steps to ensure MAVLink2 is used:

Update the telemetry module firmware to the latest version

Set to 2

Tuning

You may also need to tune some parameters of the flight controller as the default parameters are tuned assuming a GPS accuracy in the order of meters, not centimeters. For example, you can decrease and to 0.2.

RTK Connection Process

The RTK GPS connection is essentially plug and play:

1.) Start QGroundControl and attach the base RTK GPS via USB to the ground station. The device is recognized automatically.

2.) Start the vehicle and make sure it is connected to QGroundControl.

3.) QGroundControl then starts the RTK setup process (known as "Survey-In").

Survey-In is a startup procedure to get an accurate position estimate of the base station. The process typically takes several minutes (it ends after reaching the minimum time and accuracy specified in the ).

You can track the progress by clicking the RTK GPS status icon.

Once Survey-in completes, the RTK GPS icon changes to white and QGroundControl starts to stream position data to the vehicle.

Vehicle GPS switches to RTK mode. The new mode is displayed in the normal GPS status icon.

Introduction

This is a portable solution that sends the RTK corrections via a Sik Telemetry Radio link directly to the vehicle’s RTK GPS, rather than through Mission Planner. With one exception, it allows one to setup an RTK Fixed Baseline station and have it update the vehicle’s GPS with RTCM corrections without having to use a PC running Mission Planner in the field.

The exception is that, without modification, the portable base cannot “survey” itself in at a new location automatically, which is required for it to send valid RTCM corrections to the Rover or Vehicle. So, if the base station location changes, you must attach it to a PC and use the Ublox U-Center application to have the survey-in process restarted. Its still an improvement by not having to have the PC out in the field adjacent to the base RTK GPS unit.

However, if one removes the backup batteries on the base unit GPS such that it “cold” starts every power up, the Base GPS can start a new survey-in automatically.