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Topic: IR led TSAL5300 range distance (Read 503 times) previous topic - next topic

d82k

Hello,

I have connected a TSAL5300 IR led (http://www.vishay.com/docs/81008/tsal5300.pdf) to pin 3 of arduino as described here: http://www.righto.com/2009/08/multi-protocol-infrared-remote-library.html.
Using the IRRemote library it works good.
Unfortunately the distance range is about 1m.
I have used a 100ohm resistance between the led and pin, can this affect the distance and should i change resistance? Or is this a limit of the TSAL5300?

Thank you,
dk

Chagrin

Arduino pins are rated at 20ma continuous, 40ma absolute maximum current. Given that the Arduino is outputting 5V on its digital pin and the TSAL5300 has a forward voltage (Vf) of 1.35V you're driving it at 36.5ma with a 100R resistor. (5V - 1.35Vf) / 100R = .0365A

The TSAL5300 will accept up to 100ma. You need to use a transistor to provide that much current. The TSAL5300 datasheet shows a linear relationship between current and brightness so doubling the current should double the range.

But even driving it as you are a 1M range is horrible. What are you sending signals to (are the specs of the IR receiver known?) and are you sure that you've matched the receiver's modulation frequency? Try testing with other encodings if you haven't yet.

To verify you haven't damaged your TSAL5300 you can swap it out with a white or red LED and you should still get a couple meters of range (assuming a modern, high brightness 5mm/20ma LED).

fungus


Hello,

I have connected a TSAL5300 IR led (http://www.vishay.com/docs/81008/tsal5300.pdf) to pin 3 of arduino as described here: http://www.righto.com/2009/08/multi-protocol-infrared-remote-library.html.
Using the IRRemote library it works good.
Unfortunately the distance range is about 1m.
I have used a 100ohm resistance between the led and pin, can this affect the distance and should i change resistance? Or is this a limit of the TSAL5300?


Your LED needs 100 mA to function. An Arduino pin cannot supply that much current so you'll have to use an external transistor to switch it.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

d82k

Thank you both for your reply.
Hum.. this sounds much complicated than I thought... so if i reduce the resistor to 40 Ohm I should provide 0.09A which should be ok if I understood correctly.

If I am wrong, I have actually two transistors at home, 2N3904 NPN (http://www.play-zone.ch/en/fileuploader/download/download/?d=1&file=custom%2Fupload%2FFile-1336772046.pdf) and 2N3906 PNP (http://www.play-zone.ch/en/fileuploader/download/download/?d=1&file=custom%2Fupload%2FFile-1340216733.pdf).
But.. which should I use?

thank you,
dk

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