mirror of https://github.com/ArduPilot/ardupilot
126 lines
3.4 KiB
Markdown
126 lines
3.4 KiB
Markdown
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# Pixhawk4 Flight Controller
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The Pixhawk4 flight controller is sold by [Holybro](http://www.holybro.com/product/55)
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## Features
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- STM32F765 microcontroller
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- Two IMUs: ICM20689 and BMI055
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- MS5611 SPI barometer
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- builtin SPI IST8310 magnetometer
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- microSD card slot
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- 6 UARTs plus USB
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- 14 PWM outputs
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- Four I2C and two CAN ports
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- External Buzzer
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- external safety Switch
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- voltage monitoring for servo rail and Vcc
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- two dedicated power input ports for external power bricks
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## Pinout
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## UART Mapping
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- SERIAL0 -> USB
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- SERIAL1 -> UART2 (Telem1)
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- SERIAL2 -> UART3 (Telem2)
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- SERIAL3 -> UART1 (GPS)
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- SERIAL4 -> UART4 (GPS2)
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- SERIAL5 -> UART6 (spare)
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- SERIAL6 -> UART7 (spare, debug)
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The Telem1 and Telem2 ports have RTS/CTS pins, the other UARTs do not
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have RTS/CTS.
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The UART7 connector is labelled debug, but is available as a general
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purpose UART with ArduPilot.
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## RC Input
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RC input is configured on the port marked DSM/SBUS RC. This connector
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supports all RC protocols. Two cables are available for this port. To
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use software binding of Spektrum satellite receivers you need to use
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the Spektrum satellite cable.
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## PWM Output
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The Pixhawk4 supports up to 14 PWM outputs. First first 8 outputs (labelled
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"MAIN") are controlled by a dedicated STM32F100 IO controller. These 8
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outputs support all PWM output formats, but not DShot.
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The remaining 6 outputs (labelled AUX1 to AUX6) are the "auxillary"
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outputs. These are directly attached to the STM32F765 and support all
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PWM protocols as well as DShot.
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The 8 main PWM outputs are in 3 groups:
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- PWM 1 and 2 in group1
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- PWM 3 and 4 in group2
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- PWM 5, 6, 7 and 8 in group3
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The 6 auxillary PWM outputs are in 2 groups:
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- PWM 1, 2, 3 and 4 in group1
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- PWM 5 and 6 in group2
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Channels within the same group need to use the same output rate. If
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any channel in a group uses DShot then all channels in the group need
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to use DShot.
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## Battery Monitoring
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The board has two dedicated power monitor ports on 6 pin
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connectors. The correct battery setting parameters are dependent on
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the type of power brick which is connected.
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## Compass
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The Pixhawk4 has a builtin IST8310 compass. Due to potential
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interference the board is usually used with an external I2C compass as
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part of a GPS/Compass combination.
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## GPIOs
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The 6 PWM ports can be used as GPIOs (relays, buttons, RPM etc). To
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use them you need to limit the number of these pins that is used for
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PWM by setting the BRD_PWM_COUNT to a number less than 6. For example
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if you set BRD_PWM_COUNT to 4 then PWM5 and PWM6 will be available for
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use as GPIOs.
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The numbering of the GPIOs for PIN variables in ArduPilot is:
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- AUX1 50
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- AUX2 51
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- AUX3 52
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- AUX4 53
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- AUX5 54
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- AUX6 55
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## Analog inputs
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The Pixhawk4 has 7 analog inputs
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- ADC Pin0 -> Battery Voltage
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- ADC Pin1 -> Battery Current Sensor
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- ADC Pin2 -> Battery Voltage 2
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- ADC Pin3 -> Battery Current Sensor 2
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- ADC Pin4 -> ADC port pin 2
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- ADC Pin14 -> ADC port pin 3
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- ADC Pin10 -> ADC 5V Sense
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- ADC Pin11 -> ADC 3.3V Sense
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- ADC Pin103 -> RSSI voltage monitoring
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## Loading Firmware
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The board comes pre-installed with an ArduPilot compatible bootloader,
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allowing the loading of *.apj firmware files with any ArduPilot
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compatible ground station.
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## Acknowledgements
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Thanks to
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[PX4](https://docs.px4.io/en/flight_controller/pixhawk4.html) for
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images used under the [CC-BY 4.0 license](https://creativecommons.org/licenses/by/4.0/)
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