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piguy101
08-13-2011, 03:17 PM
I created an infrared remote, but the range of the remote was limited to about two feet and it had to be directly pointed at the infrared phototransistor. I would like to make the range of the remote to be about the distance of a television remote or better. I was thinking to use around 940nm wavelength, but if you think there is a better wavelenght to use what should it be? What should the viewing angle of the infrared LED be? What should the radiant intensity of the LED be? Basiclly, what can I do to increase the range of the remote using a BS2 as the micro?

Leon
08-13-2011, 03:32 PM
You probably aren't putting enough current through the IR emitter - use a transistor.

PJ Allen
08-13-2011, 03:43 PM
I did some IR experiments (http://forums.parallax.com/showthread.php?102867-Infra-red-(IR)-Data-Transmission-amp-Remote-control-Experiments-amp-Projects&highlight=infra-red) a few years ago.
I was transmitting data (as opposed to remote-control code/s.)

piguy101
08-13-2011, 03:54 PM
I did use a transistor and put the LED at about 75mA but I think the date sheet said the LED could withstand about 0.5A on a low duty cycle, should I do that?

$WMc%
08-13-2011, 04:00 PM
piguy101:
'
John Williams wrote a very useful article in Nut&Volts mag. on using Sony IR remotes and sending DATA vea a IR led. Its in the Spin-Zone section.
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I think it was called SIRCS.
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A google search should find it.

ElectricAye
08-13-2011, 04:10 PM
I did use a transistor and put the LED at about 75mA but I think the date sheet said the LED could withstand about 0.5A on a low duty cycle, should I do that?

Are you using a device with a "standard" 38 kHz carrier, etc. or is this something you're designing from scratch? Page 148 of the PE Kit labs book has a little something about using IR detectors of the sort used with TV remotes, etc. That 38 kHz carrier signal allows the system to reject other light noise in the room, an ability which effectively helps with the discrimination of signals.

PJ Allen
08-13-2011, 04:14 PM
I found that I got a lot better performance outfitting my IR receiver with what Whit called a "hoodie".

ElectricAye
08-13-2011, 04:25 PM
I found that I got a lot better performance outfitting my IR receiver with what Whit called a "hoodie".

I noticed you have shiny tile floors, and that probably helps, too. :-)

erco
08-13-2011, 10:01 PM
I created an infrared remote, but the range of the remote was limited to about two feet and it had to be directly pointed at the infrared phototransistor.

A phototransistor is much less sensitive than a 38 kHz receiver module (which can detect 30-40 feet away, because of built-in amplification & filtering). Two feet is decent range using just a phototransistor. Be proud!