Infrared Receiver

[emavil]

Hi

Anybody who knows how to receive a decoded infrared signal in PICBASIC and turn on an appropriate relay connnected to portB. 8 relays are connected to portb and IR Receiver in PortA.0. I'm using TSOP1236 IR Receiver.

[Archangel]

Here is a nice tutorial Bruce made available on his website


http://www.rentron.com/PicBasic/IR_Chips.htm

[teverett]

You would need to pick a IR transmitter. They emit very different signals. (the TSOP1236 IR will receive and decode all of them). Sony, sharp or philips ... each transmits IR differently.

http://www.hifi-remote.com/infrared/IR-PWM.shtml

[keithdoxey]

Best to use a 38kHz receiver rather than 36kHz if you are planning on decoding various protocols.

Philips (RC5 RC6 RCMM) tend to be 36kHz and uses Manchester Encoding

NEC tend to be 38kHz and uses space encoding

Sony tend to be 40kHz and uses pulse encoding

Sensitivity of the receiver drops off outside its designated centre frequency so 38k works best as a generic receiver. eg TSOP1238, TSOP1838, TSOP4838 etc

[dhouston]

TSOP1100 handles 33-57kHz carriers.

[keithdoxey]

TSOP1100 handles 33-57kHz carriers.

Thats useful to know.

Thanks Dave

[Archangel]

THANK GOD FOR GOOGLE!
http://www.datasheetcatalog.com/datasheets_pdf/T/S/O/P/TSOP1100.shtml
Or lots of us would sure be in the dark :) , Could I be the only one out here who didn't know what a TSOPxxxx was?
JS

[emavil]

Thanks a lot guys, but for now, i will NOT focus myself on the programming. Maybe later. What I would like to know is basically the detailed & simple technical functionality on how an infrared receiver works (layman explanation).

[emavil]

You would need to pick a IR transmitter. They emit very different signals. (the TSOP1236 IR will receive and decode all of them). Sony, sharp or philips ... each transmits IR differently.

http://www.hifi-remote.com/infrared/IR-PWM.shtml

thanks a lot everett, that was an excellent reference. I will study the explanations and make it as a reference.

[dhouston]

Thanks a lot guys, but for now, i will NOT focus myself on the programming. Maybe later. What I would like to know is basically the detailed & simple technical functionality on how an infrared receiver works (layman explanation).
This page gives a brief explanation of the fundamentals although it is more from the transmitter side of things.
http://davehouston.net/ir-rf_fundamentals.htm
The datasheets for any of the TSOPxxxx receivers have a block diagram that gives a good explanation of how they work. Basically, they have a photosensitive element that reacts to the 940nM wavelength of the IR typically used in consumer IR (CIR) and then a bandpass filter designed for the carrier frequency used followed by a low pass filter that demodulates the carrier. The output is the data envelope of the signal that was transmitted.