Hardware development often involves working with things that can’t be directly perceived, which is one reason good development tools are so important. In appreciation of this, [David Johnson-Davies] created the IR Remote Control Detective to simplify working with IR signals. While IR remote controls are commonplace, there are a number of different protocols and encoding methods in use across different brands. The IR Detective takes care of all of that with three main components, none of which are particularly expensive. To use the decoder, one simply points an IR remote at the unit and presses one of the buttons. The IR Detective will identify the protocol, decode the signal, and display the address and command related to the key that was pressed. The unit doesn’t consist of much more than an ATtiny85 microcontroller, a small OLED display, and an IR receiver unit. The IR receiver used is intended for a 38 kHz carrier, but such receivers can and do respond to signals outside this frequency, although they do so at a reduced range.
As a result, not only is the unit useful for decoding IR or verifying that correct signals are being generated, but the small size and low cost means it could easily be used as a general purpose receiver to add IR remote control to other devices. It’s also halfway to bridging IR to something else, like this WiFi-IR bridge which not only interfaces to legacy hardware, but does it across WiFi to boot.
Drone racing is a very exciting sport, in which there is a lot of room for hackers and makers to add that special sauce into the mix. Usually the aerial finish line requires special race-timing hardware to do the lap counting, and there are timing gate transponders available for around $40. In his project CoreIR and CoreIR-Uplink, [Michael Rickert] decided to reverse engineer the IR Protocol that goes into these beacons and made a homebrew version that mimics the original. The transponders send a 7-digit number out repeatedly to a receiver at the finish line as the UAV passes by and that helps track how fast drone pilots flew around a race track. The hack involves flipping an IR LED ON and OFF with the correct timing, and [Michael Rickert] confesses that it was not as easy as he had imagined.
Using a logic analyser he was able to capture the modulated 38Khz carrier signal and extract the timing from the original beacon, but it took a number of iterations to get the code just right. The IRRemote library has a ‘sendRaw’ function which is quite helpful in these situations and was employed for the task. He experimented with a number of Arduino boards to power the project, before finally going with the Arduino Pro Mini. He has shared the code on github, along with photos of the finished hack which replaces the original circuit. The final sketches include functions to generate the 7-digit code to uniquely identify the quadcopter, which completes the hack in itself.
If that was not enough, he’s gone a step further by coding and sharing a desktop client as well, which turns this hack into a full-fledged project and should prove quite useful for drone racers on a budget. The app is written in NodeJS and packaged using the electron framework, a choice that makes for a very simple way to create cross-platform desktop applications.
A build tutorial is available for you to get started, and if drone racing seems a bit tame, check out Drone Wars for a little more carnage.
This IR receiver based on ATtiny13 microcontroller is used to control a Media Center box via a remote. The circuit is powered by 20 pin ATX connector pin 9 “+5VSB” because it is the only pin that is powered when the computer is off, or in standby. The receiver is programmed to accept the codes from the remote by holding down the switch while pressing the remote button. The circuit can use “Girder” or “PC remote control” as controlling software on the Media Center.