3DR Pixhawk 1 Flight Controller (Discontinued)

This flight controller has been discontinued and is no longer commercially available. You can use the mRo Pixhawk as a drop-in replacement.

The 3DR Pixhawk® 1 autopilot is a popular general purpose flight controller based on the Pixhawk-project FMUv2 open hardware design (it combines the functionality of the PX4FMU + PX4IO). It runs PX4 on the NuttX OS.

Pixhawk Image

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

Key Features

  • Main System-on-Chip: STM32F427
    • CPU: 180 MHz ARM® Cortex® M4 with single-precision FPU
    • RAM: 256 KB SRAM (L1)
  • Failsafe System-on-Chip: STM32F100
    • CPU: 24 MHz ARM Cortex M3
    • RAM: 8 KB SRAM
  • Wifi: ESP8266 external
  • GPS: U-Blox® 7/8 (Hobbyking®) / U-Blox 6 (3D Robotics)
  • Optical flow: PX4 Flow unit
  • Redundant power supply inputs and automatic failover
  • External safety switch
  • Multicolor LED main visual indicator
  • High-power, multi-tone piezo audio indicator
  • microSD card for high-rate logging over extended periods of time


  • 1x I2C
  • 1x CAN (2x optional)
  • 1x ADC
  • 4x UART (2x with flow control)
  • 1x Console
  • 8x PWM with manual override
  • 6x PWM / GPIO / PWM input
  • S.BUS / PPM / Spektrum input
  • S.BUS output

Where to Buy

Originally manufactured by 3DR® this board was the original standard microcontroller platform for PX4®. While the board is no longer manufactured by 3DR, you can use the mRo Pixhawk as a drop-in replacement.

Order mRo Pixhawk from:



  • 32bit STM32F427 Cortex-M4F core with FPU
  • 168 MHz
  • 256 KB RAM
  • 2 MB Flash
  • 32 bit STM32F103 failsafe co-processor


  • ST Micro L3GD20H 16 bit gyroscope
  • ST Micro LSM303D 14 bit accelerometer / magnetometer
  • Invensense MPU 6000 3-axis accelerometer/gyroscope
  • MEAS MS5611 barometer


  • 5x UART (serial ports), one high-power capable, 2x with HW flow control
  • 2x CAN (one with internal 3.3V transceiver, one on expansion connector)
  • Spektrum DSM / DSM2 / DSM-X® Satellite compatible input
  • Futaba S.BUS® compatible input and output
  • PPM sum signal input
  • RSSI (PWM or voltage) input
  • I2C
  • SPI
  • 3.3 and 6.6V ADC inputs
  • Internal microUSB port and external microUSB port extension

Power System and Protection

  • Ideal diode controller with automatic failover
  • Servo rail high-power (max. 10V) and high-current (10A+) ready
  • All peripheral outputs over-current protected, all inputs ESD protected

Voltage Ratings

Pixhawk can be triple-redundant on the power supply if three power sources are supplied. The three rails are: Power module input, servo rail input, USB input.

Normal Operation Maximum Ratings

Under these conditions all power sources will be used in this order to power the system

  • Power module input (4.8V to 5.4V)
  • USB power input (4.8V to 5.4V)

Absolute Maximum Ratings

Under these conditions the system will not draw any power (will not be operational), but will remain intact.

  • Power module input (4.1V to 5.7V, 0V to 20V undamaged)
  • Servo rail input (4.1V to 5.7V, 0V to 20V)
  • USB power input (4.1V to 5.7V, 0V to 6V)


FMUv2 + IOv2 schematic -- Schematic and layout

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


The RC IN port is for RC receivers only and provides power. NEVER connect any servos, power supplies or batteries to it or to the receiver connected to it.

Pixhawk Connectors


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


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


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


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


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


Pin Signal Volt
1 (red) VCC +3.3V
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)

Debug Ports

Console Port

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

A convenient way to connect to the console is to use a Dronecode probe, 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 Dronecode probe to the Pixhawk SERIAL4/5 port .

Dronecode probe

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.

Console Connector

The complete wiring is shown below.

Console Debug

For information on how to use the console see: System Console (PX4 Developer Guide)

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.

Pixhawk SWD

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).

ARM 10-Pin connector pinout

All Pixhawk FMUv2 boards have a similar SWD port.

Building Firmware

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-v2_default

Parts / Housings

Supported Platforms / Airframes

Any multicopter / airplane / rover or boat that can be controlled with normal RC servos or Futaba S-Bus servos.

© PX4 Dev Team. License: CC BY 4.0            Updated: 2024-02-13 22:49:01

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