IR light switch

Hi there,

I’m working on a project where I need to check if someone throws something into a garbage can. We want to do this be make a strip with IR-LEDs and IR-Receivers. When one of the lights get’s interrupted someone throws something into the garbage can.

(I know there are different solutions, but this is how the project is at the moment)

Does someone has a circuit design maybe? Or knows some sensors I could use?

Roxlu

At first thought this seems like a simple problem, but the more i thought about it, the harder it got.

How about instead of using sensors that detect the blocking of light, you use sensors that detect reflection instead.

I think a semi-circle of reflective tape along 1/2 the inside rim, with a few emitters and detectors along the opposing rim, might work.

Keeping it clean would be a problem though.

Yuck.

Give this a look...

http://www.thebox.myzen.co.uk/Hardware/The_Sound_Square.html

Good luck, Brian

Something like a Panasonic PNA4602M is a good choice because it outputs a logic level which is a yes-no indication of whether it sees modulated (i.e., oscillating) IR light.

For the LED, any infrared-emitting LED will do (e.g., Lite-On LTE-4208), and it should be pulsed on and off at 38 kHz. I would use a transistor to not load down the Arduino with current very much.

Something like this for 1 LED/detector pair.