118 lines
3.1 KiB
Markdown
118 lines
3.1 KiB
Markdown
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# Pixhawk4-Mini Flight Controller
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The Pixhawk4-Mini flight controller is sold by [Holybro](http://www.holybro.com/product/64)
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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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- 3 UARTs plus USB
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- 8 PWM outputs
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- Two I2C and one CAN ports
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- External Buzzer
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- external safety Switch
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- dedicated power input port 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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- SERIAL6 -> UART7 (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 inside the case and labelled as debug, but is
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available as a general purpose UART with ArduPilot.
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## RC Input
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RC input is configured on the port marked RC IN. 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-Mini supports up to 8 PWM outputs. All 8 outputs support all
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normal PWM output formats. Only the first 6 outputs support DShot.
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The 8 auxillary PWM outputs are in 3 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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- PWM 7 and 8 in group3
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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-Mini 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 8 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 8. For example
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if you set BRD_PWM_COUNT to 6 then PWM6 and PWM7 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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- PWM1 50
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- PWM2 51
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- PWM3 52
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- PWM4 53
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- PWM5 54
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- PWM6 55
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- PWM7 56
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- PWM8 57
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In addition there are 4 pins on the servo rail marked CAP1 to
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CAP4. The first 3 of these are available as GPIOs in ArduPilot using
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the following GPIO numbers:
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- CAP1 58
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- CAP2 59
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- CAP3 60
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## Analog inputs
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The Pixhawk4-Mini has 4 analog inputs
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- ADC Pin0 -> Battery Voltage
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- ADC Pin1 -> Battery Current Sensor
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- ADC Pin10 -> ADC 5V Sense
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- ADC Pin11 -> ADC 3.3V Sense
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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_mini.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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