3D Robotics

The decision to port the Basic Stamp autopilot to Arduino turned out to be an unexpected opportunity to make something really cool. I've taken Jordi's open source RC multiplexer/failsafe board, and mashed it up with an Arduino clone to create "ArduPilot", perhaps the cheapest autopilot in the world. ($110! That's one-third the price of Paparazzi)

Here's what it is:

A custom PCB with an embedded processor (ATMega168) combined with circuitry to switch between RC control and autopilot control (that's the multiplexer/failsafe, otherwise known as a "MUX"). This controls navigation (following GPS waypoints) and altitude by controlling the rudder and throttle. These components are all open source. This autopilot is fully programmable and can have any number of GPS waypoints (including altitude) and trigger camera or other sensors

As with the Basic Stamp autopilot, to make a fully autonomous aircraft you need to combine this navigation autopillot with a stabilization system, for which we turn to our old friend, the FMA Co-Pilot (off-the-shelf infrared sensors and control board to keep the plane flying level), which controls the ailerons and elevator.

By using Jordi's MUX, which allows us to switch from autopilot to manual RC control in hardware, we gain several advantages over the Basic Stamp:

1) Because the switching isn't handled by the processors, we don’t need to drive servos in real time, which means we don't need stand-alone servo driver chips (thus a simpler board)

2) We also don't need “mirroring” subroutines to pass through servo commands in RC mode (simpler code)

3) Don’t need power regulator, since we’re using regulated output from the RC receiver (simpler board)

4) The built-in MUX failsafe is cheaper and simpler than using a stand-alone one.

I've taken a quick pass at the schematic and PCB (Eagle 5.0 format) for ArduPilot, although this will evolve as we go through the hardware testing cycle: Schematic, PCB board. You can buy the board here. Arduino code coming soon in alpha now.

All together, this can be the basis of a sub-$500 UAV:


--ArduPilot PCB: $10

--Boarduino kit + FTDI cable: $35 (subtract $17.50 if you already have a FTDI cable)

--PicoSwitch: $20 (we'll probably build this in the board in the next rev)[UPDATE: Jordi's now incorporated that into the board above. It's a TinyAVR chip ("IC3", $2.75) and its associated programming interface jumpers ("ISP")]

--EM-406 GPS module: $60

--Multiplexer chip : $1

--8 Samtec TSW-108-25-G-T-RA right angle servo connectors (available as a free sample): $0

(That's a $110 autopilot, thanks to the open source hardware. By comparison, the Basic Stamp version of this, with processor, development board and failsafe board, would run you $300, and it's not as powerful)


--FMA Co-Pilot: $70

Plane and RC equipment:

--Hobbico SuperStar (includes motor, battery and ESC): $109

--6-Channel radio system (with proportional control for channel 6, to calibrate FMA system): $109

--Three servos: $45

TOTAL: $440
E-mail me when people leave their comments –

You need to be a member of diydrones to add comments!

Join diydrones


  • 3D Robotics
    That should be fine, but please remember that that code is not ready to fly yet. Just for autopilot testing with a simulator on the ground now...
  • Chris... Do you think there would be any problem with doing this with a gas powered plane, just by changing the code to control a servo instead of a speed control?
  • 3D Robotics
    Good idea ;-)

  • aha thanks! I thought you'd edit a link to it on this page.. sorry
  • 3D Robotics

    Do mean the code? I posted an alpha weeks ago. Although that works, we're now improving it in a couple ways:

    --Reading GPS in binary mode and with checksums, to ensure accuracy
    --Better navigation routines with PID loops
    --Adapted to work on the production version of the board that will be sold, assembled, by a third-party this fall.
    --Ground station software.
  • the end of july is getting closer............
  • sorry about that..
  • 3D Robotics
    Here's a post on the new boards assembled. For future reference, the whole ArduPilot thread is linked off the main page here.

    Most of your questions are already answered on the site. We try to organize the site as best as possible, but sometime you may need to use the search bar.
  • Moderator
    ...and maybe even what aisle in Walmart where you could pick one up?
  • Thanks. Does anyone mind posting how to finished new boards should look like?
This reply was deleted.