[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:

Views: 312306

Comment by Peter Meister on July 31, 2009 at 9:54am
It is going to be as confusing as when I joined 30 days ago. If you continue this. Simple as that, like so many other great pieces of info, if someone has to comb through 100s of fractured blogs it only serves to hinder success for this project. My 2 cents...

Still no go on my 2.2.3 autopilot by the way. I have no other flight scenarios to test. I have tested them all. So I will be sitting back waiting for someone to find the solution to 2.2.3 actually working for someone. I would love someone to come forward with a working 2.2.3 with a setup/configuration report and a video of the flight. Until then I am going to watch the thread. On another note, I am moving fast ahead with the UAV Devboard work to create Waypoint capability. I think it has potential. It works flawless for aileronassist/stability.

Bryan & Fefenin, let me know if you get anywhere or figure anything ouit, PM me of post in the blog and I will try another test again :)



Comment by Jordi Muñoz on July 31, 2009 at 10:12am

A video from another person will not solve your problem. I don't understand why some others can fly well. You should ask them to post a video. I can make one for you, but again this will not solve your issue or whatever it is..

I have a question are you using the Arduino IDE 16?

The next version will have some improvements, including Serial TX using interrupts and Analog Conversion using interrupts too, so i will increase the performance a lot more. I also want to add cross track error, now that i have more room and power. I will eliminate NMEA forever, i know, i may shrink our community but at the end the system will be more simple and better.

Another good part of uBlox is that you can have NMEA and Binary protocol at the same time, so you can use OSD and Ardupilot at the same time using a hybrid protocol, traveling in the same line.

Comment by Jordi Muñoz on July 31, 2009 at 10:34am
Riccardo Kuebler,

Are you connecting the LIPO positive to the voltage divider? Can you snap some pictures of you setup and post it here please?


Comment by Mark Colwell on July 31, 2009 at 3:05pm
I use a 2 cell Lipo all the time connected to ESC, that sends +5.05v to ArduPilot, run a wire from +7.4 on lipo to voltage in pin on ArduPilot. LabView's bar graph is set up for 3 cells @ +12.6 v top, so you wont see green bar, but digital voltage is correct (within a few millivolts) maybe someone could add a manual select switch in LabView for 2,3, & 4 cell setups?
Comment by Bryan Cuervo on July 31, 2009 at 3:36pm
Hi Jordi,
Yes, Peter is using the Arduino IDE 16 along all the recommended hardware, software and plane. So far one person, David Low, has posted successful flights with the latest software.
Can you share with us more info on your complete setup? Have you modified the code any? Have you accomplished repeatable waypoint flights? Any additional info would be greatly appreciated!
Comment by fefenin on July 31, 2009 at 3:50pm
Jordi it is not against you but the 2.2.3 doesn't work for us , it is a fact!

i'm not asking for you to find the bug , i guess we will all together...

and i really think that the power of your project is to take different GPS protocol (NEMA is one of them) so people when they handle well arduino IDE can do whatever they want with this magic little ardupilot you've created.

if you decide to remove NEMA it's probably for a good reson but my thought is :

you should make ,every time you upgrade the code,the ardupilot compatible with the hardware before.
you've already done the NEMA parser so why not to put it in the new version?? (don't quit understand??)

no worries if i find somthing i'll tell you and Brian

i hope we will!!

i'm trying to decode the part of the code that could go wrong...that takes time....

a Flow chart would have been great to help. (thinking of making one , but never ever did)

Comment by Fred Forbes on July 31, 2009 at 5:24pm
I posted my first crack at a flow chart (roll only) as a blog a few days ago. Maybe you haven't seen it. Would be interested if you think it is the kind of thing you are looking for.

Comment by Jordi Muñoz on July 31, 2009 at 6:23pm
Fefenin and Peter,

RTL always works, or is also trying to fly west?

Comment by Jordi Muñoz on July 31, 2009 at 6:24pm
Sorry North East
Comment by Brent West on July 31, 2009 at 9:53pm
Hi Jordi,
I need to reverse my throttle, can you tell me the best way to do that?
Also, I was having problems with 2.2.3 finding waypoints, went back to 2.2.2 and seems to be working fine.


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