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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  • Hello,
    I am trying to use the ConfiTool on my laptop (an old Vaio with windows 98). The program opens allright, but the maps does not load. (I can open google map directly with Internet explorer!).
    I used the Config Tool on my desktop computer, but I would like to be able to bring Config Tool with me in the field.
    Does anybody know what I could do?
  • long time since I had time to feedback here.
    I have kind of managed to get the Ardupilot working, but it's not satisfactory.
    One thing that I would like to understand is why switching to stabilization or fly by wire (the two only programs I have tried) I'm getting very reduced throw (almost nothing) one side of ailerons (right ailerons works normaly, left ailerons hardly moves anything) when they are working perfectly both ways in manual mode???
    Another thing that happened the very first time I powered the plane : after a short moment, without me doing anything, the plane suddenly went full gaz (in manual mode) and it was impossible to kill it whathever mode I chose, throttle was not responding at all.
    If I had not been a confirmed pilot, I'm almost sure the plane would have taken off to crash a little farther.
    This behavior really killed my confidence in the Ardupilot project. Any idea? (I personaly think this is related to powering the plane with gaz not completely down...)

  • I see in the code that calibration is required for the case when only XY sensors are used but I can't find anywhere references on how the calibration is performed.

    Can you give me step by step setup instructions for Ardupilot with Ardushield V2 using Ardupilot 2.6 firmware when one is using ONLY XY sensors?

    Can you also give me step by step instructions for Ardupilot with ARDUSHIELD V2 using Ardupilot 2.6 firmware when one is using XY and Z sensors? (I will buy Z sensor in near future...) :-)

    In both cases I am not using Ardupilot to control my throttle (throttle is connected straight to RX). Is there a difference in setup if Ardupilot IS in fact controlling my throttle?

    What is the difference between STABILIZATION MODE and FLY-BY-WIRE MODE?
    I see that there are two FLY-BY-WIRE modes: A (no control on airspeed just stabilization) and B (airspeed controlled). It seems to me that FLY-BY-WIRE A MODE is IDENTICAL to STABILIZATION MODE.

    Thank you,
  • 3D Robotics

    2.6 should work fine for stabilization without GPS fix (the only mode that really needs GPS fix is with the IMU). Yes, for a flying wing, turn on Elevon Mode. We use that all the time with Funjets/Skyfuns, and it works great.
  • 3D Robotics

    As mentioned, 1.0 was designed to do that. I also think you're right that there was a navigation-only test mode in 2.4 that could do that, but it's been a long time since I looked at that code. It's really not the best way to fly a UAV, however. Why don't you just get a shield and use your FMA sensors to fly with ArduPilot controlling both navigation and stabilisation? You'll get much better performance and you'll be able to use the latest code and otherwise keep up with the project.
  • Hi Chris, I am using Ardupilot just for navigation, and the copilot sensor (FAMA direct) do the airplane stabilization.
  • 3D Robotics
    We're not supporting 2.4 anymore. I suggest you upgrade to 2.6 and solder the jumper wires for throttle control as described in the manual here. You don't need the shield if you're using an IMU, but do if you're using thermopiles.

    When you say you're using ArduPilot with copilot, what do you mean? You're just using it for navigation? We used to support that way back with ArduPilot 1.0, which is still available. I'm not quite sure how you would do that with the current code. The best thing would be to use the copilot sensors for ArduPilot and let it do everything.
  • Hi, I am using ardupilot with copilot and not the expansion shield. I installed the software 2.4.6 for easyglider, but my engine is not working even in the manual mode. I already checked the chanels in the ardupilot and engine is pluged in chanel 3 in the ardupilot (in and out). Is the version 2.4.6 only working with the expansion shield?
    Someone have already proved the 2.4.6 just with the copilot? When I plug the engine in chanels 2 or 1 I´m able to control the engine in the manual mode.
  • cool, thanks Chris.

    Bye for now,
  • 3D Robotics
    No, as long as it's a matched set (FMA XY and Z) no changes are needed. The code will autocalibrate in the air.
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