After [trandi] got his hands on a cheap R/C helicopter he realized the difficulties in actually flying a remote control helicopter. Instead of giving up, he decided to reverse-engineer the infrared protocol and then build a decoder around an ATtiny that would send commands to another microcontroller using a serial connection.
The remote’s communications protocol was decoded with the help of a Freeduino and an IR remote analysis sketch [trandi] found on the Arduino website. After importing the data into Gnuplot, there was enough data to write a sketch in Processing to visualize the infrared pulses.
After figuring out the protocol of his remote control, [trandi] built a tiny circuit to decrypt the IR commands and send them over a serial link to another microcontroller. The ATtiny45-based build doesn’t take up very much space on the perfboard making it very easy to mount on any robot of his choosing. He ended up connecting it to a Lego NTX brick allowing him to use the helicopter remote with any Lego build he can dream up.
[trandi] invested a lot of work around a cheap remote control; if the remote broke, all would be for naught. This was remedied with an IR beacon that replicates the function of the remote. The beacon is based on an ATtiny13 and can serve as a stand-alone beacon for autonomous robots or can accept serial commands from a computer. Not a bad build if you ask us.
Hmmm…. Swarm bot helicopters come to mind. Or integrate it with a camera and have a computer control its flight… Very cool!
This is damn impressive. His technique for decoding IR is exceptional, time to restart a project I had to put down…
Poor writing made me spend too much time on this blurb. Title is misleading (try that when you’re doing position calculations, like a wiimote camera), the Lego computers are called NXT, and replicating dumb IR remotes is rather old hat (see LIRC project). Not a bad project, just awful writeup.