PIXHAWK Autopilot

Flight Management Unit

This module is in active development, and will be available around late October from 3D Robotics (3DR [ https://store.3drobotics.com/products/3dr-pixhawk/ ]), (Unmanned Tech [ http://www.unmannedtechshop.co.uk/pixhawk-autopilot.html ])(BYOD [ http://www.buildyourowndrone.co.uk/3DR-Pixhawk-p/3dr-pixhawk.htm ]) and (UAV store [ http://www.uav-store.de/autopilot-1/pixhawk/#cc-m-product-8496353793 ]).

PIXHAWK is a high-performance autopilot-on-module suitable for fixed wing, multi rotors, helicopters, cars, boats and any other robotic platform that can move. It is targeted towards high-end research, amateur and industry needs and is the all-in-one combination of PX4FMU + PX4IO.

Key Features

168 MHz / 252 MIPS Cortex-M4F [ http://en.wikipedia.org/wiki/ARM_Cortex-M#Cortex-M4 ]

14 PWM / Servo outputs (8 with failsafe and manual override, 6 auxiliary,

high-power compatible)

Abundant connectivity options for additional peripherals (UART, I2C, CAN)
Integrated backup system for in-flight recovery and manual override with

dedicated processor and stand-alone power supply (fixed wing use)

Backup system integrates mixing, providing consistent autopilot and manual

override mixing modes (fixed wing use)

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

Specifications

Processor

32bit STM32F427 Cortex M4 core with FPU
168 MHz
256 KB RAM
2 MB Flash
32 bit STM32F103 failsafe co-processor

Sensors

ST Micro L3GD20H 16 bit gyroscope
ST Micro LSM303D 14 bit accelerometer / magnetometer
MEAS MS5611 barometer

Interfaces

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

Connectors

ARM MINI JTAG (J6, not populated per default): 1.27 mm 10pos header (SHROUDED, for Black Magic Probe: Samtec FTSH-105-01-F-DV-K or (untested) or Harwin M50-3600542 (Digikey [ http://www.digikey.com/product-detail/en/M50-3600542/952-1389-ND/2264370 ] or Mouser [ http://ch.mouser.com/ProductDetail/Harwin/M50-3600542/?qs=%2fha2pyFadujTt%2fIEz8xdzrYzHAVUnbxh8Ki%252bwWYPNeEa09PYvTkIOQ%3d%3d ])
- JTAG Adapter Option #1: BlackMagic Probe [ http://www.blacksphere.co.nz/main/blackmagic ], comes without cables, needs the Samtec FFSD-05-D-06.00-01-N cable (Samtec sample service [ http://www.samtec.com/suddenservice/samples/samples.aspx ] or Digi-Key Link: SAM8218-ND [ http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&KeyWords=FFSD-05-D-06.00-01-N ]) and a Mini-USB cable
- JTAG Adapter Option #2: Digi-Key Link: ST-LINK/V2 [ http://search.digikey.com/us/en/cat/programmers-development-systems/in-circuit-programmers-emulators-and-debuggers/2621880?k=st%20link%20v2 ] / ST USER MANUAL [ http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/USER_MANUAL/DM00026748.pdf ], needs an ARM Mini JTAG to 20pos adapter: Digi-Key Link: 726-1193-ND [ http://search.digikey.com/us/en/products/MDL-ADA2/726-1193-ND/1986451 ]
- JTAG Adapter Option #3: SparkFun Link: Olimex ARM-TINY [ http://www.sparkfun.com/products/8278 ] or any other OpenOCD-compatible ARM Cortex JTAG adapter, needs an ARM Mini JTAG to 20pos adapter: Digi-Key Link: 726-1193-ND [ http://search.digikey.com/us/en/products/MDL-ADA2/726-1193-ND/1986451 ]
USARTs: Hirose DF13 6 pos (Digi-Key Link: DF13A-6P-1.25H(20) [ http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=DF13A-5P-1.25H%2820%29&x=0&y=0 ])
- Mates: Hirose DF13 6 pos housing (Digi-Key Link: Hirose DF13-6S-1.25C [ http://search.digikey.com/us/en/products/DF13-5S-1.25C/H2182-ND/241752 ])
I2C and CAN: Hirose DF13 4 pos (Digi-Key Link: DF13A-4P-1.25H(20) [ http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=DF13A-4P-1.25H%2820%29&x=0&y=0 ])
- Mates: Hirose DF13 4 pos housing (Digi-Key Link: Hirose DF13-4S-1.25C [ http://search.digikey.com/us/en/products/DF13-4S-1.25C ])
USB (J5): Micro USB-B
- Mates: Cell phone data / charger cables, e.g. Digi-Key Link: ASSMANN AK67421-0.5-R [ http://search.digikey.com/us/en/products/AK67421-0.5-R/AE10418-ND/2263977 ]

Schematics

px4fmuv2.3.pdf – Schematic and layout

Peripherals

A number of peripherals have been designed for PX4 (all autopilots, including Pixhawk and FMU).

Digital Airspeed Sensor

PX4 Airspeed [ https://pixhawk.ethz.ch/px4/modules/px4airspeed ]

This digital differential airspeed sensor has a very low offset, a high resolution and most importantly: Does not suffer from the noise induced by long cables and offsets in the ratiometric output on the old analog airspeed sensors. It features a Measurement Specialties (coincidentally swiss, too) 4525DO sensor, with 1 psi measurement range (roughly up to 100 m/s or 360 km/h or 223 mp/h). Its resolution of 0.84 Pa is quite good, and delivered as 14 bit data from a 24 bit delta-sigma ADC. It also measures temperature to allow to calculate true airspeed from indicated airspeed using the MS5611 static pressure sensor on Pixhawk. As the temperature is not influenced by the heat of nearby processing components, it is much closer to the air temperature than with the previous analog sensor setup. It comes with M3 / 6-32 mounting holes. It is supported on all PX4 autopilot generation boards

External USB Port

This port can be mounted on the outside of the plane / copter / rover and provides convenient access.

External Multicolor Led

This LED has the same functionality as the in-built led and can be mounted anywhere on the system.

I2C Splitter

This splitter allows to connect multiple peripherals to the I2C port, including the external compass on the GPS.

Supported Platforms / Airframes

Any multicopter / airplane / rover or boat that can be controlled with normal RC servos or Futaba S-Bus servos. More details are available on the airframe page.

PX4 Airframes [ https://pixhawk.ethz.ch/px4/airframes/start ]