Welcome to Holybro Official Documentation.

This documentation will help you understand Holybro's official product introduction, technical specifications, pinout, tutorials, assembly, etc. If you have any comments or suggestions on our documentation, please send an email to [email protected]

Thank you

Inside the Pixhawk®​ 6X, you can find an STMicroelectronics​® based STM32H753, paired with sensor technology from Bosch®​​, InvenSense®​,​ giving you flexibility and reliability for controlling any autonomous vehicle, suitable for both academic and commercial applications.

The Pixhawk® 6X’s H7 microcontroller contains the Arm® Cortex®-M7 core running up to 480 MHz, has 2MB flash memory and 1MB RAM. The PX4 takes advantage of the increased power and RAM. Thanks to the updated processing power, developers can be more productive and efficient with their development work, allowing for complex algorithms and models.

The FMUv6X open standard includes high-performance, low-noise IMUs on board, designed for better stabilization. Triple redundant IMU & double redundant barometer on separate buses. When the PX4 detects a sensor failure, the system seamlessly switches to another to maintain flight control reliability.

An independent LDO powers every sensor set with independent power control. A vibration isolation System to filter out high-frequency vibration and reduce noise to ensure accurate readings, allowing vehicles to reach better overall flight performances.

External sensor bus (SPI5) has two chip select lines and data-ready signals for additional sensors and payload with SPI-interface, and with an integrated Microchip Ethernet PHY, high-speed communication with mission computers via ethernet is now possible.

The Pixhawk®​ 6X is perfect for developers at corporate research labs, startups, academics (research, professors, students), and commercial application.

Key Design Points

• High-performance STM32H753 Processor

• Modular flight controller: separated IMU, FMU, and Base system connected by a 100-pin & a 50-pin Pixhawk®​ Bus connector.

• Redundancy: 3x IMU sensors & 2x Barometer sensors on separate buses

• Triple redundancy domains: Completely isolated sensor domains with separate buses and separate power control

Pixhawk Baseboard Reference and Downloads

Pixhawk 6X Pro Module CAD File

Rev3 & 4

Standard Baseboard

Mini Baseboard

Pixhawk Baseboard Reference and Downloads

Pixhawk 6X Module CAD File

PX4

If you are using PX4, please refer to the PX4 user guide page for additional information.

The Holybro Pixhawk RPi CM4 Baseboard combine the Pixhawk FC module with the Raspberry Pi CM4 companion computer in on compact form factor with all the connections you need for development. It follows the Pixhawk Connector and Bus Standard, allow easy swap of FC Module with any FC that follows the Pixhawk Bus Standard. The FC Module is internally connected to RPi CM4 through TELEM2, and can also be connected via ethernet with a external cable provided. Recommend minimum specification for RPi CM4:

• Wireless: Yes

• RAM: 4GB (or 8GB)

Pixhawk 6C Mini Model A CAD 3D File

Model B CAD 3D File

Pixhawk 6C Case CAD 3D File

PWM Adapter 3D File

FC Module Only

Standard Baseboard v2A

Mini Baseboard

Standard Baseboard v1

The newest batch of Pixhawk baseboard V2 now supports switchable PWM signal voltage (3.3V or 5V). The modification requires the user to open the casing of the Pixhawk flight controller and be familiar with soldering.

For V2A RC12 & V2B RC02

To switch the PWM signal voltage, bridge the 3v3 or 5v soldering pads on the PCB by applying solder on the pads. Make sure the unused pads are cleaned and not shorted.

Pixhawk baseboard V2-A and V2-B have slightly different PCB designs. Follow the red square in the diagram below to locate the PWM voltage select soldering pad.

For V2A RC13 & V2B RC03

A newer design that provides a more stable voltage signal and easier modding process is currently available.

Find the JP1 on the PCB (default with no resistor soldered at the location), leave the spot empty for 3.3V signal voltage, and short the two soldering pads for 5V.

Two methods to flash the board:

SDK Manager:

This is a GUI-based solution by Nvidia which can be found from the link below:

Note: Keep it in mind that at the time of writing this document, we chose to install Jetpack 5.1.2.

Command Line:

You could benefit from .

The newest batch of Pixhawk 6C mini now supports switchable PWM signal voltage (3.3V or 5V). The modification requires the user to open the casing of the Pixhawk flight controller and be familiar with soldering.

Once you remove the top half of the flight controller casing, you'll notice the ribbon connector with silicone glue along its sides. The connector isn't fully adhered to, so it can be detached with a small amount of force. After removing the ribbon connector, you'll have safe access to the back side of the PCB for making modifications to the PWM signal voltage.

To switch the PWM signal voltage, bridge the 3v3 or 5v soldering pads on the PCB by applying solder on the pads. Make sure the unused pads are cleaned and not shorted.

For Pixhawk 6C mini, you have the option to change the PWM signal voltage for FMU outputs and IO outputs separately. Make sure the correct soldering pads are bridged to avoid any damage.

Pixhawk 6C mini-A (legacy) and mini-B have slightly different PCB designs. Follow the red square in the diagram below to locate the PWM voltage select soldering pad.

Popular cameras supported out of the box include IMX219 camera modules, such as the Raspberry Pi Camera Module V2. For the CSI camera, basically you could benefit from the Nvidia guide

The Holybro Jetson carrier board can have two CSI cameras connected. To give a short intro, you can try the following commands in the terminal in case your carrier board is connected to a display screen:

nvgstcapture-1.0

To open the capture on a specific CAM, you can pass the following (assuming we want to test cam1 on Orin_camera 1):

nvgstcapture-1.0 sensor-id=1

The newest batch (version RC09 and newer) of Pixhawk 6C now supports switchable PWM signal voltage (3.3V or 5V). The modification requires the user to open the casing of the Pixhawk flight controller and be familiar with soldering.

To switch the PWM signal voltage, bridge the 3V3 or 5V soldering pads on the PCB by applying solder on the pads. Make sure the unused pads are cleaned and not shorted.

For RC12 PCB design, the process is more straightforward. Locate the JP1 soldering pad at the bottom left of the PCB. Bridge the JP1 pads for 5V and unbridge to revert to 3.3V.

PX4

Pixhawk 6X Pro is supported on Master/Main or PX4 1.14.3 release and later. PX4 Firmware Target: FMUv6x

Pixhawk 6X Pro is supported in Ardupilot 4.5.0 stable release and later. Ardupilot Firmware Target: Pixhawk 6X. Ardupilot firmware can be flash via Mission Planner or QGroundControl. It can also be downloaded here:

Weight

• Outer alloy case weight: 90g

• Without Jetson and Flight Controller: 85g

Schematics

Pixhawk Baseboard Reference Schematic

CAN2 on the basboard is conneted internally to both FCU and Jetson module. The basics could be implemented from Nvidia user guide:

However, you could follow the below quick commands might make you able to loopback test the CAN connection between Jetson module and FCU on Jetson's terminal:

The last command has to have the following output if can is running OK:

To install Raspberry Pi CM4 companion compute onto this baseboard.

• Disconnect the FAN connector.

• Remove these 4 screws on the back side of the baseboard.

The Pix32 v6 is the latest update to the pix32 v5 flight controllers. It is a variant of the Pixhawk 6C. It is comprised of a separate flight controller and carrier board which are connected by a . It is designed for those pilots who need a high power, flexible and customizable flight control system.

Inside the Pix32 v6, you can find an STMicroelectronics® based STM32H743, paired with sensor technology from Bosch® & InvenSense®, giving you flexibility and reliability for controlling any autonomous vehicle, suitable for both academic and commercial applications.

The Pix32 v6’s H7 microcontroller contain the Arm® Cortex®-M7 core running up to 480 MHz, has 2MB flash memory and 1MB RAM. Thanks to the updated processing power, developers can be more productive and efficient with their development work, allowing for complex algorithms and models. It includes high-performance, low-noise IMUs on board, designed to be cost effective while having IMU redundancy. A vibration isolation System to filter out high-frequency vibration and reduce noise to ensure accurate readings, allowing vehicles to reach better overall flight performances.

This flight controller is perfect for people that is looking for a affordable and modular flight controller that can use a customized baseboard. We have made the , you can either make a custom carrier board yourself or just let us help you with it. By using a customize baseboard, you can make sure that the physical size, pinouts and power distribution requirements match your vehicle perfectly, ensuring that you have all the connections you need and none of the expense and bulk of connectors you don’t.

Block Diagram

Reference Wiring Diagram

PX4

Ardupilot

Dimension for discontinued version Model A

Betaflight Target: KAKUTEH7V2 (BF 4.3.1 or Newer)

INAV Target: KAKUTEH7V2 (INAV 5.1 or newer),

Ardupilot Target: KakuteH7v2 (Ardupilot 4.3 or newer)

PX4: (PX4 1.14 or newer) Firmware can be built using make holybro_kakuteh7v2

PX4

Supported on PX4 v1.11.0 and later.

Ardupilot

Supported in Ardupilot 4.0 and later.

Pix32v6 is supported on PX4 and later. Pix32 v6 (with SN number higher than XXXX XXX 20221112) requires or later.

Pix32 v6 is supported in Ardupilot 4.2.3 stable release and later. It uses the "Pixhawk 6C" Firmware Target. Firmware can be flash via Mission Planner or QGroundControl. It can also be downloaded here:

Must use or later, or .

Betaflight Target: KAKUTEH7MINI

INAV Target: KAKUTEH7MINI

Ardupilot

• v1.2 & prior: KakuteH7Mini

• v1.3: KakuteH7Mini-Nand

• v1.5: KakuteH7Mini (Supported in master/latest FW or 4.6.0 & later)

PX4

Firmware can be built using make holybro_kakuteh7mini

KakuteH7 Mini v1.5 is supported in PX4 main or version later than 1.15.4

PX4 Bootloader HEX file for Kakute H7 Mini v1.3 and before:

PX4 Bootloader HEX file for Kakute H7 Mini v1.5 and later: (Must use QGC Daily, or v4.4.4 or later)

Key Design Point

• High-performance ADIS16470 Industrial IMU with high accelerometer dynamic range (±40 g), perfect for accurate motion sensing in demanding UAV applications

• All New advanced durable vibration isolation material with resonance frequency in the higher spectrum, ideal for industrial and commercial drone applications

• High performance STM32H753 Processor

• Ethernet interface for high-speed mission computer integration

Features

• Triple redundant IMU & double redundant barometer on separate buses

• Modular flight controller: separated IMU, FMU, and Base system

• Safety-driven design incorporates sensors from different manufacturers and model lineups

• Independent LDO powers every sensor set with independent power control.

Rev 8 (ICM-45686) Version

Support in PX4 1.14.3 release and later.

Supported in 4.5.0 stable release and later.

Rev 3/4 Version

Pixhawk 6X is supported on PX4 and later.

Supported in Ardupilot 4.2.3 stable release and later.

The Pixhawk® 6C is the latest update to the successful family of Pixhawk® flight controllers, based on the Pixhawk® FMUv6C Open Standard and Connector Standard. It comes with PX4® pre-installed.

Inside the Pixhawk® 6C, you can find an STMicroelectronics® based STM32H743, paired with sensor technology from Bosch® & InvenSense®, giving you flexibility and reliability for controlling any autonomous vehicle, suitable for both academic and commercial applications.

The Pixhawk® 6C’s H7 microcontroller contain the Arm® Cortex®-M7 core running up to 480 MHz, has 2MB flash memory and 1MB RAM. Thanks to the updated processing power, developers can be more productive and efficient with their development work, allowing for complex algorithms and models.

The FMUv6C open standard includes high-performance, low-noise IMUs on board, designed to be cost effective while having IMU redundancy. A vibration isolation System to filter out high-frequency vibration and reduce noise to ensure accurate readings, allowing vehicles to reach better overall flight performances.

The Pixhawk® 6C is perfect for developers at corporate research labs, startups, academics (research, professors, students), and commercial application.

Key Design Points

• High performance STM32H743 Processor with more computing power & RAM

• New cost-effective design with low-profile form factor

• Newly designed integrated vibration isolation system to filter out high frequency vibration and reduce noise to ensure accurate readings

• IMUs are temperature-controlled by onboard heating resistors, allowing optimum working temperature of IMUs

Pix32 v6 STM32 Pinout

Pix32 v6 RC04 Reference Schematic

Pix32 v6 Flight Controller Module Connector Datasheet (Panasonic-AXK5S-6S)

Pix32 v6 FMU 100Pin Header PinMap

Pix32 v6 Baseboard DXF file

Pix32 v6 Baseboard RC03 Schematic

CAD Files

3D Print

Pixhawk Baseboard v1 to v2

Processors & Sensors

• FMU Processor: STM32H743

The Holybro Kakute H7 v2 Flight Controller is full of features including integrated Bluetooth, HD camera plug, dual plug-and-play 4in1 ESC ports, 9V VTX ON/OFF Pit Switch, barometer, OSD, 6x UARTs, 128MB Flash for Logging, 5V and 9V BEC, and bigger soldering pad with easy layout and much more. The Kakute H7 v2 builds upon the best features of its F7 predecessor and further improves on hardware components and layout. With the additional integrated Bluetooth chip onboard, you can perform configuration and tuning wirelessly on your phone with the SpeedyBee Android & IOS App. The Kakute H7 is DJI HD ready. It has an easy plug-and-play port with an on-board 9V regulator designed to power your HD video transmitter such as the DJI/Caddx FPV Air Unit & Caddx Vista while supporting analog system. It features an onboard “VTX ON/OFF Pit Switch” that allows you to completely power off the video transmitter using a switch on your RC transmitter. Great if you are working on your drone, waiting for the GPS to get a fix, getting ready for a race while preventing it from overheating or interfering with others flying. It has 6x dedicated UART ports with built-in inversion for peripherals (UART2 is used for Bluetooth telemetry), a 128 MB Flash for logging, Dual plug-and-play 4in1 ESC connectors, allowing easy plug-and-play support for x8 & Octocopter configuration and keeping it simple and clean.

The integrated BetaFlight OSD makes it easy to display important information on your FPV display like battery voltage, flight time, warnings, RSSI, smart audio features and more. It is also ready for autonomous flight with the on-board barometer. There are LED & buzzer pad, I2C pad (SDA & SCL) for external GPS/Magnetometers. The integrated BetaFlight OSD makes it easy to display important information on your FPV display like battery voltage, flight time, warnings, RSSI, smart audio features and more. It is also ready for autonomous flight with the on-board barometer. There are LED & buzzer pad, I2C pad (SDA & SCL) for external GPS/Magnetometers.

The Pixhawk® 6C Mini is the latest update to the successful family of Pixhawk® flight controllers, based on the and . It shares the same STMH743 microprocessor and sensors as the Pixhawk 6C. Compared to the standard Pixhawk 6C, this Mini version has a built-in PWM header, and some ports have been removed in order to fit this Mini form factor.

Inside the Pixhawk® 6C Mini, you can find an STMicroelectronics®-based STM32H743, paired with sensor technology from Bosch® & InvenSense®, giving you flexibility and reliability for controlling any autonomous vehicle, suitable for both academic and commercial applications.

The Pixhawk® 6C Mini's H7 microcontroller contains the Arm® Cortex®-M7 core running up to 480 MHz and has 2MB flash memory and 1MB RAM. Thanks to the updated processing power, developers can be more productive and efficient with their development work, allowing for complex algorithms and models.

The FMUv6C open standard includes high-performance, low-noise IMUs on board, designed to be cost-effective while having IMU redundancy. A vibration isolation system to filter out high-frequency vibration and reduce noise to ensure accurate readings, allowing vehicles to reach better overall flight performances.

The Pixhawk® 6C Mini is perfect for developers at corporate research labs, startups, academics (research, professors, students), and commercial applications.

Description:

The Holybro Kakute H7 Mini is a Flight Controller full of features including onboard VTX ON/OFF Pit Switch with battery voltage, HD System/VTX & 4in1 ESC plugs, barometer, OSD, 6x UARTs, easy soldering layout and much more. The Kakute H7 Mini builds upon the best features of its F7 predecessor and further improves on hardware components and layout. HD ready, it has an easy plug to power HD system like Caddx Vista while supporting analog system. It features an onboard “VTX ON/OFF Pit Switch” that allows you to completely power off the video transmitter using a switch on your RC transmitter. Great if you are working on your drone, waiting for the GPS to get a fix, getting ready for a race while preventing it from overheating or interfering with others flying.

It has 6x dedicated UART ports with built-in inversion for peripherals, 4in1 ESC plug, and x8 compatible with M5-M8 Signal Pads, allowing easy support for x8 Octocopter configuration. The integrated BetaFlight OSD makes it easy to display important information on your FPV display like battery voltage, flight time, warnings, RSSI, smart audio features and more. It is also ready for autonomous flight with the on-board barometer. There are LED & buzzer pad, I2C pad (SDA & SCL) for external GPS/Magnetometers.

Description

The Holybro Kakute H7 v1 Flight Controller is full of features including integrated Bluetooth, dual plug-and-play 4in1 ESC ports, HD camera plug, barometer, OSD, 6x UARTs, full Blackbox MicroSD card slot, 5V and 9V BEC, easy soldering layout and much more.

The Kakute H7 builds upon the best features of its F7 predecessor and further improves on hardware components and layout. With the additional integrated Bluetooth chip onboard, you can perform Betaflight configuration and tune wirelessly on your phone with the SpeedyBee Android & IOS App. The Kakute H7 is DJI HD ready. It has an easy plug-and-play port with an onboard 9V regulator designed to power your HD video transmitter like DJI/Caddx FPV Air Unit & Caddx Vista while supporting analog systems.

Betaflight Target: KAKUTEH7

INAV Target:

Below are the main difference between Pixhawk 6C and Pixhawk 6C Mini

Ports

These ports are not available in the Pixhawk 6C Mini (compared to the "standard" Pixhawk 6C):

Holybro Kakute H7 V2 PINIO Setup for INAV 5.1 This manual applies to INAV 5.1, Holybro Kakute H7 V2 and covers the topic of PINIO functionality setup so that following goals are achieved:

1. Built in Bluetooth is active when INAV is NOT armed

2. Built in Bluetooth is disabled when INAV is armed

3. VTX is always enabled or activated on a switch

Must use PX4 1.13.1 Stable and newer.

Features

• Fully compatible with Jetson Orin NX/Nano

• Combines the power of Pixhawk & Jetson in a small form factor

• Jetson & controller are connected via UART, CAN, and Ethernet Switch

Jetson Orin NX/Nano Connectors

• Gigabit Ethernet

  • Connected to both Jetson & controller via Ethernet Switch (RTL8367S) - 8-pin JST-GH - RJ45

    • Ethernet port & switch powered by the circuit as the Pixhawk

  • 8-pin JST-GH

Flight Controller Connectors

• Pixhawk Bus Interface - 100 Pin Hirose DF40 - 50 Pin Hirose DF40

• Redundant Digital Power Module Inputs

  • I2C Power Monitor Support

Processors & Sensors

• FMU Processor: STM32H743

  • 32 Bit Arm® Cortex®-M7, 480MHz, 2MB memory, 1MB SRAM

• IO Processor: STM32F103

  • 32 Bit Arm® Cortex®-M3, 72MHz, 64KB SRAM

• On-board sensors

  • Accel/Gyro: ICM-42688-P

  • Accel/Gyro: BMI088 (BMI055 discontinued due to the end of production of the sensor)

  • Mag: IST8310

Electrical data

• Voltage Ratings:

  • Max input voltage: 6V

  • USB Power Input: 4.75~5.25V

  • Servo Rail Input: 0~36V

Mechanical data

• FC Module Connector Type:

• Dimensions: 44.8 * 44.8 * 13.5mm

• Weight: 36g

Interfaces

• 16- PWM servo outputs (8 from IO, 8 from FMU)

• 3 general purpose serial ports

  • Telem1 - Full flow control, separate 1.5A current limit

  • Telem2 - Full flow control

Other Characteristics

• Operating temperature: -40 ~ 85°c

Processors & Sensors

• FMU Processor: STM32H743

  • 32 Bit Arm® Cortex®-M7, 480MHz, 2MB memory, 1MB SRAM

• IO Processor: STM32F103

  • 32 Bit Arm® Cortex®-M3, 72MHz, 64KB SRAM

• On-board sensors

  • Accel/Gyro: ICM-42688-P

  • Accel/Gyro: BMI088 (BMI055 discontinued due to the end of production of the sensor)

  • Mag: IST8310

Electrical data

• Voltage Ratings:

  • Max input voltage: 6V

  • USB Power Input: 4.75~5.25V

  • Servo Rail Input: 0~36V

Mechanical data

• Dimensions (Model A Legacy): 53.3 * 39 * 16.2 mm

• Dimensions (Model A Current): 54.3x39x17.5 mm

• Dimensions (Model B): 58.3x39x18.15 mm

• Weight (Model A Legacy): 39.2g

Interfaces

• 14- PWM servo outputs (8 from IO, 6 from FMU) with hardware switchable 3.3V and 5V signal mode

• 2 general purpose serial ports

  • Telem1 - Full flow control, separate 1.5A current limit

Other Characteristics

• Operating temperature: -40 ~ 85°c

Serial Connection

Pixhawk TELEM2 is internally connected to the Jetson module. Let us first check the connection on the Jetson terminal. Consider having a MAV connection to companion computers in advance. Check for the details. For a sanity check, you could run on /dev/ttyTHS0

Processors & Sensors

• FMU Processor: STM32H753

  • 32 Bit Arm® Cortex®-M7, 480MHz, 2MB flash memory, 1MB RAM

• IO Processor: STM32F103

  • 32 Bit Arm® Cortex®-M3, 72MHz, 64KB SRAM

• On-board sensors ()

  • Accel/Gyro: 3x ICM-45686 (with BalancedGyro™ Technology)

  • Barometer: ICP20100 & BMP388

  • Mag: BMM150

• On-board sensors ()

  • Accel/Gyro: BMI088/ICM-20649

  • Accel/Gyro: ICM-42688-P

  • Accel/Gyro: ICM-42670-P

Electrical data

• Voltage Ratings:

  • Max input voltage: 6V

  • USB Power Input: 4.75~5.25V

  • Servo Rail Input: 0~36V

Mechanical data

• Dimensions

  • Flight Controller Module: 38.8 x 31.8 x 14.6mm

  • Standard Baseboard: 52.4 x 103.4 x 16.7mm

  • Mini Baseboard: 43.4 x 72.8 x 14.2 mm

Interfaces

• 16- PWM servo outputs with hardware switchable 3.3V or 5V signal mode (requires base board modification)

• R/C input for Spektrum / DSM

• Dedicated R/C input for PPM and S.Bus input

• Dedicated analog / PWM RSSI input and S.Bus output

Other Characteristics

• Operating temperature: -40 ~ 85°c

Flash EMMC

First, we need to have the CM4 up and running. We need to prepare the hardware for it first. Considering the fact that you have already mounted your CM4 onto the baseboard do the following to be able to flash any required image on RPi CM4:

1. Switch the Dip-Switch on Holybro Pixhawk 6X+CM4 base board (located on top of UART&I2C port) to RPi

2. Connect the baseboard to your desktop computer USB-C CM4 Slave port used power & flash the RPi CM4. There may be a prompt on some systems like macOS to allow the connection. Please allow it! Otherwise, where to connect? 😀

3. You need to use usbboot:

Linux / Cygwin / WSL

Clone this repository on your Pi or other Linux machine. Make sure that the system date is set correctly, otherwise, Git may produce an error.

This git repository uses symlinks. For Windows builds clone the repository under Cygwin:

Note: sudo isn't required if you have write permissions for the /dev/bus/usb device.

macOS

From a macOS machine, you can also run usbboot, just follow the same steps:

1. Clone the usbboot repository

2. Install libusb (brew install libusb)

3. Install pkg-config (brew install pkg-config)

4. (Optional) Export the PKG_CONFIG_PATH so that it includes the directory enclosing libusb-1.0.pc

If the build is unable to find the header file libusb.h then most likely the PKG_CONFIG_PATH is not set properly. This should be set via export PKG_CONFIG_PATH="$(brew --prefix libusb)/lib/pkgconfig".

If the build fails on an ARM-based Mac with a linker error such as ld: warning: ignoring file /usr/local/Cellar/libusb/1.0.26/lib/libusb-1.0.dylib, building for macOS-arm64 but attempting to link with file built for macOS-x86_64 then you may need to build and install libusb-1.0 yourself:

Running “make” again should now succeed!

After running rpiboot the below screen from your terminal should say that you are good to go for flashing a new image onto your CM4 board.

Note: if there are any pop-ups after this stage to eject an unknown disk, simply ignore them.

• You can now install your favorite Linux distro, e.g. Raspberry Pi OS 64bit, using The rpi-imager. Make sure to add wifi and ssh settings (hidden behind the gear/advanced symbol).

1. Once done, unmount the volumes, and power down the CM4 by unplugging the USB-C CM4 Slave.

2. Switch Dip-Switch back to EMMC.

3. Power on CM4 by providing power to the USB-C CM4 Slave port.

4. To check if it’s booting/working, either check HDMI output, or connect via ssh (if set up in rpi-imager, and wifi is available).

Connect PX4 to CM4 via serial

Pixhawk 6X talks to CM4 using Telem2 (/dev/ttyS4).

1. To enable this MAVLink instance, set the params: - MAV_1_CONFIG: TELEM2 - MAV_1_MODE: Onboard - SER_TEL2_BAUD: 921600 8N1

2. reboot the FMU

3. On the RPi side, you can connect it to Wifi using a router or a Wifi Dongle.

Try out MAVSDK-Python

1. Make sure the CM4 is connected to the internet, e.g. using a wifi, or ethernet.

2. Install MAVSDK Python:

1. Copy an example from the .

2. Change the system_address="udp://:14540" to system_address="serial:///dev/serial0:921600"

3. Try out the example. Permission for the serial port should already be available through the dialout group.

You can also use your own power supply to power the RPi CM4 baseboard.

Durandal is a flight controller designed by Holybro utilizing the STM32H7 microcontroller series. As an increasing number of drone companies and developers need to run more powerful models and build on more embedded memory capabilities, Durandal is designed to offer the performance upgrade for development needs.

The advantage will come in handy with intensive calculation features are required. Harnessing our extensive controller building experience in the past years, we have implemented a new vibration absorption system into the mechanical design of the hardware and integrated an IMU heater for sensor temperature control.

Key Design Points:

• High performance H7 Processor with a clock speed up to 480 MHz

• Redundant inertial measurement unit (IMU) from Bosch® & InvenSense®

• Vibration isolation system to filter out high frequency vibration and reduce noise to ensure accurate readings

• IMUs are temperature-controlled by onboard heating resistors, allowing the optimum working temperature of IMUs

• 2 power ports & 5 general purpose serial ports

Technical Specifications

Processors & Sensors

• Main FMU Processor: STM32H743

  • 32 Bit Arm ® Cortex®-M7, 480MHz, 2MB memory, 1MB RAM

• IO Processor: STM32F100/F103

Electrical Data

Voltage Ratings:

• Max input voltage: 6V

• USB Power Input: 4.75~5.25V

• Servo Rail Input: 0~36V

Current Ratings:

• Telem1 Max output current limiter: 1.5A

• All other ports combined output current limiter: 1.5A

Mechanical Data:

• Dimensions:80*45*20.5mm

• Weight: 68.8g

Interfaces

• 13 PWM outputs (8 from IO, 5 from FMU)

• 5 general purpose serial ports

• • 3 with full flow control

Pinout

ESC Port

VTX Port

Pinout

Pinout

Processors & Sensors

• FMU Processor: STM32H753

Link-local networking setup between CM4 and FC

Local cable

To set up a local ethernet connection between CM4 and the flight computer, the two ethernet ports need to be connected using a 8 pin to 4 pin connector.

The pinout of the cable is:

8 pin: 1 A 2 B 3 C 4 D 5 (not connected) 6 (not connected) 7 (not connected) 8 (not connected)

to 4 pin: 1 B 2 A 3 D 4 C

IP setup on CM4

Since there is no DHCP server active in this configuration, the IPs have to be set manually: First, connect to the CM4 via ssh by connecting to the CM4’s wifi (or use a Wifi dongle). Once the ethernet cables are plugged in, the eth0 network interface seems to switch from DOWN to UP.

You can check the status using:

You can also try to enable it manually:

It then seems to automatically set a link-local address, for me it looks like this:

This means the CM4’s ethernet IP is 169.254.21.183.

IP setup on FC

Now connect to the NuttX shell (using a console, or the MAVLink shell), and check the status of the link:

For me it is DOWN at first.

To set it to UP:

Now check the config again:

However, it doesn’t have an IP yet. I’m going to set one similar to the one of CM4:

And check it:

Now the devices should be able to ping each other.

Note that this configuration is ephemeral and will be lost after a reboot, so we’ll need to find a way to configure it statically.

Ping test

First from the CM4:

And from the FC in Nuttx Shell:

MAVLink/MAVSDK test

For this, we need to set the mavlink instance to send traffic to the CM4’s IP:

For an initial test we can do:

This will send MAVLink traffic on UDP to port 14540 (the MAVSDK/MAVROS port) to that IP which means MAVSDK can just listen to any UDP arriving at that default port.

To run a MAVSDK example, install mavsdk via pip, and try out an example from .

For instance: