IR detection at a distance

Hi everyone,

I'm thinking about making a long-distance IR detector. The IR source will be a 10W 950nm LED, and I'm using a simple IR LED to detect it. The signal is very weak at long distances (tens of meters), so I thought about modulating the source signal and locking in on it using some kind of IC which can demodulate and amplify the signal. Is there an easy way to do it in an arduino? Which ICs do you recommend?

Hi.

Try to use TSOP4838 instead a simple IR Phototransistor. Make use of Ken Shirriff's IR Remote Library.

When you send a IR code instead a simple on-off IR LED, you eliminates any interferences of, for example, the sun or fluorescent bulbs. Make tests with it.

By other way, if you need very long distances to detect any pass through, think about to use a IR Laser LED.

modulating the source signal and locking in on it using some kind of IC which can demodulate and amplify the signal.

That is the way most IR receivers work. The most common ones are optimized to detect 38 kHz modulation, but receivers for other frequencies are available.

Have you thought about focusing the transmitter beam?