IR proximity

Hi everyone, I've been looking through all of the threads and tutorials online on how to make a simple IR proximity sensor, but I can't get it going. My numbers from the analogRead() does not change whatsoever. I would like to start out from scratch and try to see if you guys can guide me through it. Please help.

my IR/reciever:

My Materials: 1. IR emitter 2. IR receiver (2pin) 3. 1k-100k resistor

IR Devices are digital. Is there a particular reason you are hooking them up to analog pins and using analogRead()?

How did you have them hooked up?

What code were you using?

We need much more than "I couldn't get it going"

Normally people use pre-built sensors such as the Sharp IR distance sensors. For example:

IR Devices are digital.

They are?


IR Devices are digital.

They are?

Brainfart, was thinking about PIR motion detection for some reason.

There are actually 3 different types of IR proximity detectors - if we rule out PIR devices, which operate on heat pickup and not light pickup.

The one type, which is normally called "IRPD" (ala your title) works at distances of 6-18", and simply signals yes/no. These use TV IR remote style pickup devices, which operate at 32-56 Khz, and have built-in amplifiers and bandpass filters, so they have 100X the sensitivity of your IR [u]phototransistor/diode[/u] [whichever it really is]. Yours is not an "IR/receiver", this is an IR receiver,

The second type of detector is the Sharp IR ranger that joe mentioned. That variety actually measures distance and gives an analog output vs distance.

Then, the 3rd type of detector is just for very tiny distances, eg under 1/2" or so, and typically used for line detection in robots. Your devices would work for that. This explains the idea,

which operate on heat pickup and not light pickup

There's a difference? (apart from wavelength)

More specifically, PIR operates at around 10,000 nm, deep into the infrared, and IR Leds/phototransistors work at 790-860 nm, at near infared. Our bodies can reflect light at 800 nm, but don't generate light at those frequencies, just like we don't emit visible light in the dark. Our bodies do generate heat at 10,000 nm. [something like that].