Bluetooth remote?

I really really really hate infrared remote controls. When I'm sitting comfortably, I always have trouble pointing it just right. Of course I realize this is probably an issue with my setup, but it wouldn't be an issue if the remote used Bluetooth.

So I figured I'll write an Android remote control app that pairs with a little Bluetooth box that has an infrared led pointing right at the decoder. Thing is, the programming is no issue, but I haven't built anything more involved than an AV-switch box in the last decade.

So I'm hoping someone can give me some guidance on using off-the-shelf components to pair/send/receive Bluetooth commands and decode them so I can flash the little infra-red LED. I'm perfectly happy to handle storage and all the other requirements on the phone.

Padlock7 years ago
It might be best to use an old blue tooth headset. Connect the speaker output to a bridge rectifier made from signal diodes, then to a resister, and then to a transistor, and then to an IR LED.

That way you would only have to send a sound wave of the the correct frequency (depends on your remote) to the headset, and it should theoretically work...
KingCoder (author)  Padlock7 years ago
Ahhh! I never thought of it that way!

So how would I do the reverse - you know, record the IR signal from the remote so I can generate the correct audio on the phone?
Well - this is where it could get tricky. The voltage the LED is powered at may vary from remote to remote.

To do it purely with electronics, you would need to open up your remote and connect leads to the IR LED. Then connect the leads to a regulator that would diminish the voltage to about .75 volts. It's important to get it around as near this as possible. After that, connect it to a 3.5mm jack, plug it into your computer and record the "sound" when you press a button.

Now, you could also record the IR LED with a video camera, and then dissect it frame by frame on the computer to decipher the hertz. Then you would just play a square wave of the same frequency.

Thinking it over, you would have to alter the design. If you used a normal rectifier, then it would fire the transistor on both the positive and negative values of the wave, resulting in an almost continuous (theoretically, perfectly continuous) light. This is not the case- replace the rectifier with a single diode to allow just the negative or just the positive. (It shouldn't matter which if they are the same wavelength.)