Bluetooth control for your DSLR or just about any other IR operated device

Just the other day we were reading a Reddit thread asking about how to control a television with a smartphone. The conversation started by talking about adding an IR LED to the phone.  Then it was suggested that there should be standalone Bluetooth devices that convert commands to IR, and came around to the ideas that TV’s should ship with native Bluetooth hardware. We couldn’t agree more but we’re also not about to replace our TV just for this option. That’s why we were delighted to find this project waiting on our tip line. It’s a method of controlling a camera shutter from a smartphone using Bluetooth. But the technique will work for any device which uses an infrared remote control.

The video after the break shows two different devices controlling the camera shutter. As you can see in the diagram above, the iPhone is the master controller, connecting to a Bluetooth headset mounted on the camera. That headset was altered to feed the speaker connections into an IR LED pointed at the camera’s receiver. The iPhone plays an encoded audio track matching the IR remote command, resulting in the properly formatted message flashing on the LED. The watch doesn’t have the ability to playback audio, but it can send a message to the phone, which then plays the proper audio track through the headset.

Comments

  1. Brian says:

    Given that the most common IR remote carrier frequency is 38kHz, doesn’t this imply that the DAC in the headset needs to be able to faithfully handle frequencies far above the range of human hearing? Are these headsets really overengineered to handle such ultrasonic frequencies? Otherwise I wondered if the ‘audio signal’ could contain just the actual codes and the IR LED automatically modulates that over the proper carrier frequency. However the article makes no mention of this and makes reference to a ‘simple led’. Thanks for any clarification anyone can offer.

    • ka010 says:

      It’s just an IR LED soldered to a headphone jack, plugged into a (stereo)bluetooth headset, nothing more.

      I tested the idea with some sony cameras and a tankbot toy and it worked very well, so my guess is these operate on a frequency low enough to replicate.

      The headset only amplifies the signal and therefore extends the range, aside from that it shouldn’t make a difference.

      Finally, don’t take this too seriously, it’s a fun hack that’s all.

  2. Whatnot says:

    Erm.. audio over a headset only reaches about 9KHz, or 18KHz if it’s for music, and IR commands are in the range of 38KHz to 40KHz.

  3. StefanM says:

    Erhm, a lot of new tvs ship with wifi/ethernet and iOS + Android apps available :)
    I have played around with the idea of an PIC18 with usb put into my stereo to control it from the music playing pc next to it and make a script that turns it on and of together with the computer!

    • Some guy says:

      Hrm. I use an arduino to manage 4 ir emitters connected to Comcast boxes. I presently have the box hooked up to a machine that presents a web UI (styled like a remote), but no reason you couldn’t use a $13 BT module instead. If you do a minimalist setup instead of a whole dev board, total project cost would be like $25 for BT control of IR device.

  4. mosey says:

    waste of time and probably doesn’t work.

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