IR Question

[cfernandez]

Hi,

I want to use two leds IR (received & transmiter) together in the same
circuit for when I put close any object to IR leds, my circuit start. I need
too that this solution be very low power, my circuit is powered with AA
battery.

Anybody can help me with this ? Know what is the best circuit for this ?

Thank you very much!!!!

Best Regards,

[Guest]

Can you be more specific about the object that is to trigger your sensor? A sensor that will respond to _any_ object in its proximity doesn't exist. Do you want something to break a beam? Do you want to detect metallic objects? What about clear objects? Have you thought about objects that may accidentally come into the range of the sensor, activating your device when you don't want it to?

Is the sensor normally closed or normally open? Meaning, does the object actuating the sensor stop the light being transmitted or allow it to be transmitted.

One place to start looking would be cadmium sulfide photoresistors. The amount of light hitting the surface corresponds to its resistance.

Also, reflective object sensors sound like they might suit your project. These are an LED/Phototransistor pair, in one package.

[cfernandez]

I want to make a lock-door battery supply that use a RFID card to open the lock. For this I want to use IR proximity detector for know when the card is close to the reader and then wake-up the PIC and read and verify the card. If the card is ok then open the lock, if not put a sound error, and then put the PIC in sleep mode again.

This is my project.