DIY Infrared Transmitter for IPhone, IPod

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Introduction: DIY Infrared Transmitter for IPhone, IPod

Create a Infrared transmitter for any portable mp3 device, ie phones, music players etc.
This tutorial is for creating the Infrared transmitter only.

Can be used with iPhone App DSLR.BOT. http://dslrbot.com 
Used for controlling Canon EOS, Nikon, Penta and Sony Cameras.

The way this transmitter works is it sends infrared on and off signals from the audio playback coming from your headphone jack. Having saved an audio file with the correct on and off timings, you can play back this audio track through your portable music player and trigger infrared devices.

This transmitter works better with a WAV audio playback, however this has been successfully tested as an MP3 audio track.  The WAV track generally produces  a clearer signal as they can playback a 38 KHz modulation (Infrared frequency rate), by dividing the frequency between the two stereo channels. 19 KHz for the left channel and an inverse 19KHz signal for the right.

To better illustrate this the left channel will play an on and off signal ..
0101010101
The right channel will produce the in-between signals for the off time ..
1010101010
Therefor each channel will take turns producing a infrared signal creating a higher frequency rate, equal to that of an infrared remote control.

The Items needed for this DIY project are ..
1) Infrared LEDs 940 nm 2x
2) 3.5 mm stereo headphone minijack

Step 1: Prepare the Headphone Jack

The first thing to do is strip the wire ends then twist the ground wires together. The ground wire is usually the wire unprotected by a coloured casing.

Step 2: Attach Infrared LEDs

Connect the two infrared LEDs to the left and right channel.
Make sure the two LEDs are in reverse from one another. 

LED 1, + goes to white wire and - goes to red wire.
LED 2, - goes to white wire and + goes to red wire.

You can generally tell the direction of + and - from the direction of the diode inside the clear plastic. As long as the LEDs are opposite from one another the signal should work.

Once this is done bend the LED wires up to prevent the headphone jack wires from slipping loose. 

Step 3: Tape the Wires

To clean up, we need to place electrical tape around each of the exposed wires.
What I've done is tape up the Left channel and RIght channel separately and place another tape around the ground wires to prevent any unwanted wires being crossed. 

Once this is done you are ready plug it in any portable music player to playback an audio track with infrared timings. 

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    104 Comments

    why this ir transmitter not working with any of my smartphones ?

    iphone 4s

    iphone 6s

    galaxy s7

    galaxy j1

    when
    i press a button on remote app like zaza remote or ASmart remote no
    voltage come from 3.5mm jack. its always 0V. i test it with IR LED and
    color LED and low voltage bipolar lamps. when i press a button on remote
    app nothing happen on audio jack. please help me dear friend. thanks so
    much

    it's because those apps are only designed for built-in android ir and not for headphone jack diy infrared sensors. this app seems to do the job well:

    https://play.google.com/store/apps/details?id=com.ir_remoter

    Hi
    Could someone please explain why 2 LEDs are needed?
    Wouldn't it work with just 1 LED? All my TV remotes only have 1...
    thanks

    it a sine wave in positive side drive the LED that is connected + to left and - to right and after that in negative side of wave the other led getting drive. it the reason that you should use 2 LED. in remote controls is different and the remotes make their own wave and transmit it trough IR Led.

    Two leds create the needed 38000- 39000 Hz "lightwave", while audio devices can at most support 20000-30000 Hz audiowave.

    I read somewhere that you'll double the frequency range by using both channels and reverse one. You'll basically double the amount of peaks from your transmitter.

    I would also be curious as to the logic behind using two LEDs.

    Couldn't you just as easily use two regular diodes between the left and right signal with the positive of the LED connected in between them? Then the LED negative would go to ground, and we only used 1 LED. this circuit also doesn't leave any floating grounds. The only concern I would have about this would be the LED possibly discharging the circuit too soon?. The main benefit of the diodes which I could see in this version would be that the LED will not flash until a voltage threshold is reached. Also there will be no possibility for current to drop negative on the LED cathode (+) due to differentials between the channels. Instead it will only drop negative when there is no "ON" (also it will drop negative just after the "ON" signal and it will stay there until the next "ON").

    Even without the diodes, if you combine the left and right signals you will still end up with effectively twice the sample rate (compared with a mono signal) because each channel can carry on or off signals. So if the signals are combined then either channel can carry the "ON" signal and the net effect would be the LED flashing. In this case the negative voltage drop on both channels would be because of the one way current flow nature of diodes (even ones which emit light), there would be no protection from differential signals in this circuit. I don't see why this wouldn't work, too, so long as the software is designed around a mono signal.

    If it's really about setting up some sort of frequency cascade, or something else, I would like to see some evidence or something. Somebody set me straight with a link! :-) If it is about some sort of cascade, then couldn't one of the LEDs be replaced with a regular diode? This would still allow the signal to move forward at all times until the frequency is enough to discharge the LED.

    cheers!

    I read the patent and I'm pretty sure I follow the logic. I still don't understand why this is necessary.

    Is it because the pulses of an IR remote are so fast that a single on-off signal cannot be generated fast enough via an audio signal? They don't look so fast (the blink patterns). It seems like you should be able to accomplish this with 1 audio channel (or dual mono, L & R, combined back into 1 channel). Provided that when the audio tone pulses the voltage rises high enough(and fast enough) for the LED to emit. Also the voltage must drop quickly enough that the light is out long enough to actually pulse. I think it would be much easier to just use a pwm output (although that is probably defeating the whole purpose :-)

    How to build/make Infrared reciver for android phone iPhone with headphone jack. Please tell me..
    Thanks for it.