mRo Pixhawk Flight Controller (Pixhawk 1)

WARNING

PX4 does not manufacture this (or any) autopilot. Contact the manufacturer for hardware support or compliance issues.

The mRo Pixhawk^® is a hardware compatible version of the original Pixhawk 1. It runs PX4 on the NuttX OS.

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The controller can be used as a drop-in replacement for the 3DR^® Pixhawk 1. The main difference is that it is based on the Pixhawk-project FMUv3 open hardware design, which corrects a bug that limited the original Pixhawk 1 to 1MB of flash.

Assembly/setup instructions for use with PX4 are provided here: Pixhawk Wiring Quickstart

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This autopilot is supported by the PX4 maintenance and test teams.

Key Features

• Microprocessor:

  • 32-bit STM32F427 Cortex^® M4 core with FPU
  • 168 MHz/256 KB RAM/2 MB Flash
  • 32 bit STM32F100 failsafe co-processor
  • 24 MHz/8 KB RAM/64 KB Flash

• Sensors:

  • ST Micro L3GD20 3-axis 16-bit gyroscope
  • ST Micro LSM303D 3-axis 14-bit accelerometer / magnetometer
  • Invensense^® MPU 6000 3-axis accelerometer/gyroscope
  • MEAS MS5611 barometer

• Interfaces:

  • 5x UART (serial ports), one high-power capable, 2x with HW flow control
  • 2x CAN
  • Spektrum DSM / DSM2 / DSM-X® Satellite compatible input up to DX8 (DX9 and above not supported)
  • Futaba^® S.BUS compatible input and output
  • PPM sum signal
  • RSSI (PWM or voltage) input
  • I2C
  • SPI
  • 3.3 and 6.6V ADC inputs
  • External microUSB port

• Power System:

  • Ideal diode controller with automatic failover
  • Servo rail high-power (7 V) and high-current ready
  • All peripheral outputs over-current protected, all inputs ESD protected

• Weight and Dimensions:

  • Weight: 38g (1.31oz)
  • Width: 50mm (1.96")
  • Thickness: 15.5mm (.613")
  • Length: 81.5mm (3.21")

Availability

• Bare Bones - Just the board (useful as a 3DR Pixhawk replacement)
• mRo Pixhawk 2.4.6 Essential Kit! - Everything except for telemetry radios
• mRo Pixhawk 2.4.6 Cool Kit! (Limited edition) - Everything you need including telemetry radios

Building Firmware

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Most users will not need to build this firmware! It is pre-built and automatically installed by QGroundControl when appropriate hardware is connected.

To build PX4 for this target:

make px4_fmu-v3_default

Debug Ports

Console Port

The PX4 System Console runs on the port labeled SERIAL4/5.

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A convenient way to connect to the console is to use a Zubax BugFace BF1, as it comes with connectors that can be used with several different Pixhawk devices. Simply connect the 6-pos DF13 1:1 cable on the Zubax BugFace BF1 to the Pixhawk SERIAL4/5 port.

The pinout is standard serial pinout, designed to connect to a 3.3V FTDI cable (5V tolerant).

3DR Pixhawk 1		FTDI
1	+5V (red)		N/C
2	S4 Tx		N/C
3	S4 Rx		N/C
4	S5 Tx	5	FTDI RX (yellow)
5	S5 Rx	4	FTDI TX (orange)
6	GND	1	FTDI GND (black)

The wiring for an FTDI cable to a 6-pos DF13 1:1 connector is shown in the figure below.

The complete wiring is shown below.

INFO

For information on how to use the console see: System Console.

SWD Port

The SWD (JTAG) ports are hidden under the cover (which must be removed for hardware debugging). There are separate ports for FMU and IO, as highlighted below.

The ports are ARM 10-pin JTAG connectors, which you will probably have to solder. The pinout for the ports is shown below (the square markers in the corners above indicates pin 1).

INFO

All Pixhawk FMUv2 boards have a similar SWD port.

Pinouts

TELEM1, TELEM2 ports

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	TX (OUT)	+3.3V
3 (blk)	RX (IN)	+3.3V
4 (blk)	CTS (IN)	+3.3V
5 (blk)	RTS (OUT)	+3.3V
6 (blk)	GND	GND

GPS port

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	TX (OUT)	+3.3V
3 (blk)	RX (IN)	+3.3V
4 (blk)	CAN2 TX	+3.3V
5 (blk)	CAN2 RX	+3.3V
6 (blk)	GND	GND

SERIAL 4/5 port

Due to space constraints two ports are on one connector.

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	TX (#4)	+3.3V
3 (blk)	RX (#4)	+3.3V
4 (blk)	TX (#5)	+3.3V
5 (blk)	RX (#5)	+3.3V
6 (blk)	GND	GND

ADC 6.6V

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	ADC IN	up to +6.6V
3 (blk)	GND	GND

ADC 3.3V

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	ADC IN	up to +3.3V
3 (blk)	GND	GND
4 (blk)	ADC IN	up to +3.3V
5 (blk)	GND	GND

I2C

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	SCL	+3.3 (pullups)
3 (blk)	SDA	+3.3 (pullups)
4 (blk)	GND	GND

CAN

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	CAN_H	+12V
3 (blk)	CAN_L	+12V
4 (blk)	GND	GND

SPI

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	SPI_EXT_SCK	+3.3
3 (blk)	SPI_EXT_MISO	+3.3
4 (blk)	SPI_EXT_MOSI	+3.3
5 (blk)	!SPI_EXT_NSS	+3.3
6 (blk)	!GPIO_EXT	+3.3
7 (blk)	GND	GND

POWER

Pin	Signal	Volt
1 (red)	VCC	+5V
2 (blk)	VCC	+5V
3 (blk)	CURRENT	+3.3V
4 (blk)	VOLTAGE	+3.3V
5 (blk)	GND	GND
6 (blk)	GND	GND

SWITCH

Pin	Signal	Volt
1 (red)	VCC	+3.3V
2 (blk)	!IO_LED_SAFETY	GND
3 (blk)	SAFETY	GND

Serial Port Mapping

UART	Device	Port
UART1	/dev/ttyS0	IO debug
USART2	/dev/ttyS1	TELEM1 (flow control)
USART3	/dev/ttyS2	TELEM2 (flow control)
UART4
UART7	CONSOLE
UART8	SERIAL4

Serial Port Mapping

UART	Device	Port
UART1	/dev/ttyS0	IO debug
USART2	/dev/ttyS1	TELEM1 (flow control)
USART3	/dev/ttyS2	TELEM2 (flow control)
UART4
UART7	CONSOLE
UART8	SERIAL4

Schematics

The board is based on the Pixhawk-project FMUv3 open hardware design.

• FMUv3 schematic -- Schematic and layout

INFO

As a CC-BY-SA 3.0 licensed Open Hardware design, all schematics and design files are available.