reading IR photoresistor

[dhouston]

dhouston, you said that I should send a ultrasound pulse to find distance. But how would I track the position of a specific object (one with a IR emitter, for example) without using anything too complex or expensive like a camera? Thanks for any advice.

I don't think there's any easy (or cheap) way to do this, especially if you want both range and direction as you've indicated elsewhere.

You might get some ideas from reading how the Sharp IR rangefinders work but you should note that they cannot tell you the direction to the object and they also require a reflective object instead of using an IR emitter on the target.

• http://www.acroname.com/robotics/inf...arp/sharp.html

If you can modulate the IR emitter and use IR receivers designed for that modulation frequency, you can identify your target. Maybe, with multiple receivers and triangulation you can find the direction. However, the IR receivers have AGC circuitry built in that affect signal strength and they are designed to merely output a digital pulse not a continuous analog signal so you get no indication of signal strength.