qrar
You can use this package to decode any QR codes spotted by your Parrot AR.Drone's camera.
Prerequisites
The QR code module used requires Cairo and FFmpeg; I used Homebrew to install both of these on Mac OS X:
brew install cairo ffmpeg
Example
This program outputs all of the decoded QR codes to the console:
var QRAR = ;var drone = ; var codes = drone; codes; codesstart;
This program starts an ar-drone REPL:
var arDrone = ;arDrone;
So if you pipe the output of the first program (decode.js) to the second (repl.js):
node decode.js | node repl.js
Then you can show QR codes like these to your drone and it will obey!
takeoff()
land()
See felixge/node-ar-drone for the available commands. There are lots of free QR code generators online and apps that work from a smartphone (in fact you can just tweak the above image URLs to get started).