Symetrical outputs are not directly compatible with your PC input.

You must connect the - of each channel and link to the ground.

Left + | Left -, Ground, Right - | Right +

Try to connect the LEDs between both +

Originally Posted by XianLi

Symetrical outputs are not directly compatible with your PC input.

You must connect the - of each channel and link to the ground.

Left + | Left -, Ground, Right - | Right +

Try to connect the LEDs between both +

Not so clear...

this way?!?

1st Sketch > You must connect B and D to the phone's ground.

2nd Sketch > You must connect K and M to the phone's ground.

Originally Posted by XianLi

1st Sketch > You must connect B and D to the phone's ground.

2nd Sketch > You must connect K and M to the phone's ground.

it's weird: before reading this reply I tested connections as depicted in my sketches... and only ONCE my device reacted to the transmitted signal; I was no more able to replicate de event!
I had a similar result a week ago, when testing this method with the PC, and I found out it was a matter of wrong frequency of the carrier.

I'll have to do lot of tests, to define which carrier frequency and which WAV file frequency I must use...

I'll also try to connect phone GND this time...

Thanks.

You can use 44100 or 48000Khz for the frequency.

Don't forget that using only 1 LED directly connected to the audio input is not the best solution. Low level signal must be software amplified and normalized which will result with more distortions than a Full hardware solution.

The iCouchPotatoe "IR to Audio" piece of Hardware just require a normalization of your recorded signal.

I tried and gave up the only "1 LED" solution because it is not efficient enough and you get too much different results according to the Remote Control used.

You should try to put a visible light filter (non exposed film) around the LED to prevent Low and High IR light pollution. Daylight and Incandescent Light Bulb are IR friendly and will distort the IR Signal from the remote you want to capture.

Originally Posted by XianLi

You can use 44100 or 48000Khz for the frequency.

Don't forget that using only 1 LED directly connected to the audio input is not the best solution. Low level signal must be software amplified and normalized which will result with more distortions than a Full hardware solution[...]

Actually I manually recreate the whole signal! The IR led completely deletes the carrier, so all I get is just kind of a "square wave" which shows when the carrier is present and when not.

Once I know my re-created signal IS working, I'll write a program which automatically recreate the signal.

To do it by hand, I just create a 18000 Hz carrier and I "silence" it in correspondance with silence part of the sampled signal.

You can see this process in the image I posted:
http://img381.imageshack.us/img381/5...pionatope3.gif

At the top of the image you see the signal as I recorded it with the audio card, with no changes.
Below there is the carrier, silenced where needed.

It's not so clear which frequency to use, both for sampling and for recreating the signal. In theory I should sample at 76000 to properly sample a 38000 Hz signal, but it does not work: I don't see the carrier.

Then,
I recreated the signal in tracks with different frequencies, but I got strange results upon copying waveform among tracks with differen frequencies...
Can't be more precise, didn't do prpoper & enough tests yet...

Thats seriously cool !

Excellent Project XianLi. Great work !

damn it, I can't get it working anymore with my damned phone!!!

I can't understand: if it worked ONCE, why doesn't it work anymore?!????

About connecting phone "audio -" to phone GND... this link talks about THREE GNDs...?

They are all the same (only the pin name matters) and just labelled differently in the description.

There is a BIG update: IT WORKS!
I was eventually able to use my Nokia 6680 to control my SKY decoder!

But there is a REALLY weird thing: I obtained this with just ONE single IR LED!!
I wonder how it is possible??!?

I play a WAV file with these features:
- PCM
- 48000 Hz
- 32 bit
- stereo

But I actually connect the led to ONE channel, although I spent quite a lot of time creating a proper stereo signal with inverted phase into a channel!

I'll do more tests with other devices, just to see if it's depending on the SKY decoder of it is a general behaviour.

BTW, thanks Xianli for last tip about GND!

The file I used:
http://www.planetmobile.it/jumpjack/1.wav