# Holybro Pixhawk 4

> Open-source flight controller based on the Pixhawk FMUv5 standard. Features STM32F765 processor at 216MHz, triple redundant IMUs, barometer, and magnetometer. Runs ArduPilot or PX4 autopilot firmware.

## Quick Facts

- **Brand:** Holybro
- **Board Type:** flight-controller
- **Price:** ~$124.99
- **Product Readiness:** developer
- **CPU:** STM32F765
- **CPU Architecture:** ARM Cortex-M7
- **CPU Cores:** 1
- **RAM:** 512KB SRAM
- **Flash:** 2MB
- **USB:** USB-C
- **Power:** 4.9-5.5V via power module
- **Operating Voltage:** 3.3V
- **Dimensions:** 44x84x12mm
- **Weight:** 33.3g
- **SD Card:** microSD

## Open Source

- **Firmware:** Yes
- **Schematics:** Yes
- **PCB Layout:** Yes

## Compatible Firmware

ardupilot, px4

## Use Cases

- drone
- uav
- autonomous-vehicle
- robotics
- drone-flight-controller

## Components

- **STM32F765** (MCU): 32-bit ARM Cortex-M7 @ 216MHz, 2MB flash, 512KB SRAM — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.st.com%2Fresource%2Fen%2Fdatasheet%2Fstm32f765vi.pdf&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)
- **STM32F100** (MCU): IO co-processor, ARM Cortex-M3 @ 24MHz — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.st.com%2Fresource%2Fen%2Fdatasheet%2Fstm32f100cb.pdf&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)
- **ICM-20689** (IMU): 6-axis accelerometer and gyroscope — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Finvensense.tdk.com%2Fwp-content%2Fuploads%2F2016%2F06%2FDS-000143-ICM-20689-v2.1.pdf&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)
- **BMI055** (IMU): 6-axis accelerometer and gyroscope (redundant) — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.bosch-sensortec.com%2Fmedia%2Fboschsensortec%2Fdownloads%2Fdatasheets%2Fbst-bmi055-ds000.pdf&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)
- **IST8310** (Magnetometer): 3-axis digital magnetometer for compass heading — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fintofpv.com%2Fattachment.php%3Faid%3D8104&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)
- **MS5611** (Barometer): High-resolution barometric pressure sensor for altitude estimation — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.te.com%2Fcommerce%2FDocumentDelivery%2FDDEController%3FAction%3Dshowdoc%26DocId%3DData%2BSheet%257FMS5611-01BA03%257FB3%257Fpdf%257FEnglish%257FENG_DS_MS5611-01BA03_B3.pdf&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)

## Protocols

- **UART**
- **I2C**
- **SPI**
- **CAN**
- **PWM**

## Description

# Holybro Pixhawk 4

The Pixhawk 4 is an open-source flight controller designed and manufactured by Holybro, based on the Pixhawk FMUv5 open standard. It features a powerful STM32F765 main processor running at 216MHz with triple redundant IMU sensors for highly reliable flight performance.

## Key Features

- **Triple Redundant IMUs**: ICM-20689, BMI055, and IST8310 sensors for reliable attitude estimation and failover
- **High-Performance MCU**: STM32F765 Cortex-M7 at 216MHz with 2MB flash and 512KB SRAM
- **Dedicated IO Processor**: STM32F100 Cortex-M3 handles failsafe I/O operations
- **16 PWM Servo Outputs**: 8 from IO processor, 8 from FMU
- **2 CAN Buses**: For DroneCAN peripherals
- **Open Source**: Full schematics, PCB layout, and firmware available under open-source licenses

## Sensors

- **IMU 1**: ICM-20689 (accelerometer + gyroscope)
- **IMU 2**: BMI055 (accelerometer + gyroscope)
- **Magnetometer**: IST8310
- **Barometer**: MS5611

## Interfaces

- 5 serial ports (UART/USART) including GPS and telemetry
- 2 CAN buses
- 1 I2C bus
- 1 SPI bus
- 16 PWM servo outputs (8 IO + 8 FMU)
- Dedicated R/C input (S.BUS, Spektrum/DSM, CPPM)
- Dedicated S.BUS output
- 2 analog power input ports
- USB-C connector
- MicroSD card slot for logging

## Power

- Input voltage: 4.9-5.5V (via power module)
- USB power: 4.75-5.25V
- Servo rail: 0-36V
- Operating temperature: -25 to 85°C

## Physical

- Dimensions: 44 x 84 x 12mm
- Weight: 33.3g (plastic case) / 49g (aluminum case)

## Firmware

Compatible with both major open-source autopilot stacks:
- **PX4**: Full support as a reference platform
- **ArduPilot**: Full support for Copter, Plane, and Rover

## Where to Buy

- [Holybro Official](https://openhardware.directory/r?to=https%3A%2F%2Fholybro.com%2Fproducts%2Fpixhawk-4&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export) — $124.99
- [OpenELab](https://openhardware.directory/r?to=https%3A%2F%2Fopenelab.io%2Fproducts%2Fpixhawk-4&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export) — €219.00

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fholybro.com%2Fproducts%2Fpixhawk-4&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FPX4%2FPX4-Autopilot&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fdocs.px4.io%2Fmain%2Fen%2Fflight_controller%2Fholybro_pixhawk4.html&ref=openhardware.directory&product=holybro-pixhawk-4&source=md-export)

## Tags

`pixhawk`, `flight-controller`, `drone`, `autopilot`, `fmuv5`, `holybro`, `px4`, `ardupilot`, `open-source`, `stm32`

## Images

![Holybro Pixhawk 4](https://nbg1.your-objectstorage.com/openhardware-directory/entities/holybro-pixhawk-4/d9fda02e7135.jpg)
![Holybro Pixhawk 4](https://nbg1.your-objectstorage.com/openhardware-directory/entities/holybro-pixhawk-4/9d0a3e97b49c.jpg)
![Holybro Pixhawk 4](https://nbg1.your-objectstorage.com/openhardware-directory/entities/holybro-pixhawk-4/4d88d296e7f1.jpg)
![Holybro Pixhawk 4](https://nbg1.your-objectstorage.com/openhardware-directory/entities/holybro-pixhawk-4/262a88a26ac3.jpg)
![Holybro Pixhawk 4](https://nbg1.your-objectstorage.com/openhardware-directory/entities/holybro-pixhawk-4/88ac3e809e8c.jpg)
![Holybro Pixhawk 4](https://nbg1.your-objectstorage.com/openhardware-directory/entities/holybro-pixhawk-4/c9804a0c5f4c.jpg)
![Holybro Pixhawk 4](https://nbg1.your-objectstorage.com/openhardware-directory/entities/holybro-pixhawk-4/bbed653265a1.jpg)
![Holybro Pixhawk 4](https://nbg1.your-objectstorage.com/openhardware-directory/entities/holybro-pixhawk-4/9af4545f5f4b.jpg)

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