Electronic – How to make a wired input IR demodulator

controlinfraredmicrocontrollerremote

Objective: I'm trying to make a wired infrared input for a microcontroller. Incoming signal would come from a remote control device that has an IR emitter output jack.

I believe that all I need is the demodulator and perhaps schmitt trigger portion since the incoming signal will be well controlled and will not contain IR noise or variations in level.

notes: I've found a few older ICs that were designed for use with a separate diode and seem that they could fit the bill but are not available any more. I also found a Vishay line of apparently current devices (VSOP584) that could work but are very tiny and I'm not sure that I could fab one up in a way that would survive. I have to think that a relatively easy to build circuit could demodulate the signal since it's wired and doesn't suffer most of the issues that a real IR input would have.

I think I have 3 options:

A) use an ir emitter coupled to an ir receiver inside my device.
B) keep searching for an IC that will do the demodulation.
C) design a demodulator (perhaps try with a basic envelope detector).

Any suggestions on which option I should take?

Best Answer

Something like a tsop31238 IR 38Khz receiver should do the trick (transmission range about 40m). Most handsets modulate the IR at 38kHz when sending out the code. Its a nice three legged device and contains all the circuitry you need to make an easy interface. (+V, 0V and data out).

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To create a wired option from a standard universal control make a end cap to go over the controller. Inside the 'cap' is the IR 38kHz receiver wired to a suitable socket (say a 3 pin 3.5mm jack socket).

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