Read directly from the IR Led

Everything related to protocols and IR codes
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Rantamplan
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Joined: Fri Apr 29, 2016 6:40 pm

Read directly from the IR Led

Post by Rantamplan »

Hi Greetings all, I take this opportunity to introduce myself a little, I am a lover of technologies and technical work in spectacles would like to know if it is possible and how to read and store the code emitted by a LED infra red remote control air conditioning Ariston with arduino, following forum
http://forum.arduino.cc/index.php?topic=226454.0
I want to replicate IR commands from arduino for a team AC Ariston, but do not have the right tsop.
It is possible to read directly from the IR Led welding without using TSOP?
Congratulations and thanks for your work.
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AnalysIR
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Re: Read directly from the IR Led

Post by AnalysIR »

Yes.

Follow our blog post here
https://www.analysir.com/blog/2014/05/2 ... eceiver-2/

However, using a dedicated IR receiver is easier and they cost less the $1 each or can be had for free from old TVs, VCRs or DVD players.
TSOP34438 is a good one for AC units.

Alternatively, you can get IR component kits via our website
https://www.analysir.com/blog/product/i ... rter-kits/
Rantamplan
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Joined: Fri Apr 29, 2016 6:40 pm

Re: Read directly from the IR Led

Post by Rantamplan »

Thank you very much for the information, but what I want to do is read directly from the LED on the remote control, without receiver, you can copy the order of the issuer?
20160501_094451.jpg
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AnalysIR
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Re: Read directly from the IR Led

Post by AnalysIR »

Infact the solution offered in my previous post will be the simplest approach by far!

To tap into the IR emitter directly there are a number of things you must do:

- IR receivers normally invert the logic of the IR signal & decoding firmware expects an inverted signal.
- so you will need to invert the signal you get at the emitter, to use existing libraries like IRremote or IRLib etc
- the voltage across the emitter LED will be 1.2->1.5 volts.
- So you will need to translate that to 5V or 3V3 logic (You may find a logic level signal is driving Q2 in your photo, or at least the resistor driving the base of Q2)
- Finally, the biggest problem is that the signal going thru the emitter is a fully modulated signal with carrier at one of the CIR frequencies (30,33,36,38,40,56 kHz)
- For ACs this is mostly 38kHz
- So you will need method of removing the carrier from the signal and inverting it to feed it into any existing library.


The good news is that you could customise the sketch I linked above to do just that, once you have found a logic level signal on the PCB (or via external circuitry)

Do let me know how you get on.

PS: much simpler to use the sketch/circuit I posted earlier.
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