3D Robotics

ArduPilot (Legacy) main page




[This original ArduPilot board, now called the "Legacy ArduPilot" is no longer produced or officially supported by the DIY Drones dev team, and this page is maintained just for historic reasons. However, there are still many users of it out there and it still works fine. The user group for Legacy ArduPilot users, for both thermopile and IMU use, is here.]


ArduPilot is a full-featured autopilot based on the Arduino open-source hardware platform. It uses infrared (thermopile) sensors or an IMU for stabilization and GPS for navigation. It is the autopilot used to win the 2009 Sparkfun Autonomous Vehicle Competition.

The hardware is available from Sparkfun for $24.95. An expansion board ("Shield") kits that includes an airspeed sensor, a 3.3v power regulator for 3.3v GPS modules and other sensors and cables and connectors for easy attachment of the XY and Z sensors, is available from our own store for $57.20.


User f

ArduPilot features include:

  • Can be used for an autonomous aircraft, car or boat.
  • Built-in hardware failsafe that uses a separate circuit (multiplexer chip and ATTiny processor) to transfer control from the RC system to the autopilot and back again. Includes ability to reboot the main processor in mid-flight.
  • Multiple 3D waypoints (limited only by memory)
  • Altitude controlled with the elevator and throttle
  • Comes with a 6-pin GPS connector for the 4Hz uBlox5 or 1hz EM406 GPS modules.
  • Has six spare analog inputs (with ADC on each) and six spare digital input/outputs to add additional sensors
  • Supports addition of wireless modules for real-time telemetry
  • Based on a 16MhZ Atmega328 processor. Total onboard processing power aprox 24 MIPS.
  • Very small: 30mm x 47mm
  • Can be powered by either the RC receiver or a separate battery
  • Four RC-in channels (plus the autopilot on/off channel) can be processed by the autopilot. Autopilot can also control four channels out.
  • LEDs for power, failsafe (on/off), status and GPS (satellite lock).


ArduPilot requires the free Arduino IDE to edit and upload the code to the ArduPilot board.

The code is currently optimized for the Mutiplex EasyStar three-channel powered glider and FMA sensors, but can be modified for other aircraft and sensors. It uses the rudder/ailerons and elevator to maintain level flight and navigate to GPS waypoints. It supports a desktop setup utility and ground station software. It also includes a "fly-by-wire" mode that simply stabilizes RC flight. The main code is ArduPilot2.x.zip in the download section of our Google Code repository, where x is the latest version.

What you need to make a fully-functional autopilot:

Open source extras:

  • If you want to build your own board from scratch, the necessary files and component lists are here.
  • [Note: you shouldn't need this, since this code is loaded on the ArduPilot board at the factory] Latest multiplexer code (for the board's second processor, an Attiny, which runs the failsafe system) is here.
    Instructions for loading this code are here.

Recommended UAV setup:


Airframe option one: Hobbico SuperStar (49" wingspan, $95, shown above). This is an inexpensive, good flying high-wing trainer with ailerons. It can be hand launched in a park or take off from a runway, and replacement parts are readily available in case of a crash. If you want much better performance with this aircraft, you can upgrade it to a brushless motor, speed controller and a LiPo battery. [If you don't already have one, you'll also need a balancing charger and power supply.] Note: any stable aircraft with both ailerons (for stabilization) and rudder (for navigation) can work, so feel free to experiment with what you've got.


Airframe option two (recommended for ArduPilot 2.x): EasyStar (shown above). Performance can be improved with the modifications described in this post.

You'll also need:

  • A six or seven channel RC transmitter and receiver, with at least one toggle switch (ideally three-position but two-position will work, too, although you will have to mix channels to have access to both autopilot modes in the air), such as the Futaba 7C.
  • Some servos (at least three for ArduPilot 1.0; at least two for ArduPilot 2.x) and at least three female-to-female servo cables to connect the RC receiver to ArduPilot.

Cool optional extras for your UAV:

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  • Developer
    My last several test flights with diving & tight turns was caused by frayed wires to rudder servo, I found this problem when I had to upgrade landing gear, I have been using the uBlox for these flights, I now have throttle connected thru ArduPilot will test more today, I still manually control aileron /flaps but may change to elevator if diving issue continues, Partial overcast today.
  • 3D Robotics
    Marty, yes as you discovered, the latest 1.0 code is there. Seungkwon Baek was confused about which files are part of ArduPilot and which are part of the standard Arduino distro.
  • Fefenin, I just tried it with 16 and it works also, cheers. Also had a deeper look in the repository and it looks as if the Ardupilot 1.0 code available to download is the most recent.
  • @Marty
    as i suggested the arduino 0015 version compiles it nicely!!
    just swap from arduino version 17 to 15 it'll work!

    i just ordered my Ublox + adapter
    i'll let you know when i receive it if the diving issues disappears.
  • ok
    let me try it with the 15 IDE compiler later on...
    i'm moving all my stuff today .
    i promise i'll try it tonight , it 's 12 o clock here.
  • Hi Fefenin,

    When you verified/compiled the ardupilot 1.0 code you did not get the following error ?

    In function 'void loop()':
    error: 'reset_PIDs' was not declared in this scope In function 'void throttle_control()':
    In function 'void yaw_control()':

    Someone else who tried it the other day also got the same error. The reason I asked Chris was that I thought a more advanced version of the 1.0 code was developed (I think it had NMEA in the title) but it was linked here on ning and not in the repository. The latest versions of ardupilot do not run on the now superseded 168 boards of which 100's were sold which is why I was chasing the 1.0 code. I'm not asking for anymore development to be done on 1.0.
  • marty,
    first of all the version avaible for download worked great for arduimo IDE under the 17 ,
    and i'm sure you can use it with the 17 but you'll have to map the files in applet folder i would guess.
    so the compiler would kmow they are here.

    the version 2.3 can work exactly as the V1.0 so why should we keep the V1.0???
    by putting the WALK_AROUND mode on in the .h file you are emulating the V1.0
    that works great for me as well!!

    give it a try again it 'll work for sure
  • I understand that Ardupilot1.0 is no longer supported but it seems a shame that most of the 1.0 code isn't available in the repository. The version available to download does not compile correctly.
  • 3D Robotics
    Those header files are in the Arduino distro. If you just follow the instructions in the manual, everything will work fine.

    Also, you don't need any of those ArduPilot files you mentioned. The failsafe firmware comes pre-loaded in the board, and ArduPilot 1.0 has been replaced by a configuration option in 2.3. Spend a little more time with the manual and all will become clear.
  • i'm trying to bulid my ArduPilot system.
    i got the code(ArduPilot1.0, Fail_Safe_v15, and so on) from the your libraries(http://code.google.com/p/ardupilot/).
    But i cannot find the header files(WProgram.h, pins_arduino.h ...).
    let me konw where it is exactly or send me by e-mail?
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