IR help

[dhouston]

Hi,

Use a IR receiver. Make sure you use a IR receiver using the same
carrier frequency used by your remote control.

Example of IR receiver: Siemens SFH 506

Better yet use a broadband IR receiver that covers all the carrier frequencies used by all remotes (except B & O).

• http://www.elenota.pl/pdf/Vishay/82252.pdf

It's very easy to use a PC soundcard (or chip) to view and/or record the output wave form.

• http://davehouston.net/learn.htm
  http://www.zelscope.com/

[geckogrotto]

Ok will look over the sites and datasheets but whats the best way (command) to read the pulses in using picbasic. pulsin?

[skimask]

Ok will look over the sites and datasheets but whats the best way (command) to read the pulses in using picbasic. pulsin?

I've used pulsin to read Sony type IR commands without a problem...but, to each their own...

[dhouston]

It depends on the protocol. If the protocol uses pulse width (or space width) modulation, PulsIn will work but some protocols are a bit more difficult. Sampling the pulsetrain every 25µS (or less) will work for almost all protocols, especially if you know the carrier frequency which will let you refine the numbers by using the nearest integral number of carrier cycles to match the sampled widths. What are you trying to accomplish?

[geckogrotto]

Hey Dave I'm working on a universal remote of sorts for some cameras.
By sampleing the pulsetrain you mean like this?
COUNT GPIO.4, 1, Pulsedata

[dhouston]

By sampleing the pulsetrain you mean like this?
COUNT GPIO.4, 1, Pulsedata

There are both DIY and commercial devices that will do this. Of course, most folks who post here are wheel reinventors.

By sampling the pulsetrain I mean checking the pin every 25µS (or less) and setting a bit in an array to indicate its state. You end up with something like...

• 11111100000111000111000000111000111000000000000000

which is an image of the pulsetrain where each digit represents a 25µS sample.

IR receiver modules are active low, so you'll get an inverted output with 0s where there's IR and 1s where there's none.