IR Remote pc reader

[stuee]

Hi.
Is there a schematic for preferably usb or serial ir reader.
I have a projector i purchased off ebay but turns out no remote, i made a post on a forum for codes but no one had them as its a unknown brand but someone said they have a remote for it i can borrow. I want to read the codes on my pc so i can then store them incase of emergency but also put them in my Logitech remote.

Is there any schematics out there?
Ps replacement remote they want $60 for lol

cheers
Stuart

 

[dougy83]

You can probably just connect a phototransistor to your PC microphone input (connect L+R wires together). Then record each button press using a sound recorder application. If you view the waveform, it will look somewhat like a AC-coupled squarewave. If it doesn't, then either your microphone input doesn't have a built-in bias (there is a work-around for this), or the phototransistor is backwards.

 

[Nigel Goodwin]

You don't want a phototransistor, what you want is an IR receiver, this strips off the carrier and provides a rough representation of the original modulation - 'rough' because accurate pulse widths don't survive the trip (which is why RC's use various schemes such as Manchester coding or CIRC's).

 

[dougy83]

I've used phototransistors for this purpose in the past and decoded all codes of the remotes I had in my house. The carrier is removed by the slow response of the phototransistor.

 

[Nigel Goodwin]

I've used phototransistors for this purpose in the past and decoded all codes of the remotes I had in my house. The carrier is removed by the slow response of the phototransistor.

Far easier to just use the proper component for the job, and far easy to obtain - as you will have numerous scrap items at home containing them

And considering you use photo-transistors to measure the carrier frequency (if you had any need to) it's hardly 'stripping' the carrier off.

Incidentally, for the OP, here's a veroboard layout for feeding an IR signal to a PC audio input, where you can record and display it using Audacity (or similar).

 

[dougy83]

Far easier to just use the proper component for the job, and far easy to obtain - as you will have numerous scrap items at home containing them
And considering you use photo-transistors to measure the carrier frequency (if you had any need to) it's hardly 'stripping' the carrier off.

It was far easier for me to use a phototransistor as it was available and didn't require an external power source when connected to the mic. input of a PC. It was simply a phototransistor on a 3.5mm jack, without any extra components. The carrier was not present in the audio recording, nor in DSO capture of the phototransistor response, so yes, it was effectively 'stripping' the carrier.

 

[stuee]

So I found a schematic for transceiver to serial and aparently winlirc will read the cades is this the bad way to do compared to the sound recorder way?

Also nigel. Silly question but did you used to live in a town called Louth?

 

[Nigel Goodwin]

Also nigel. Silly question but did you used to live in a town called Louth?

No, never lived there, never been there, and while I've heard of it I don't have much of a clue where it might even be