Invert logic with Sharp distance sensor?

Development Boards Arduino
1

Hi

I have a Sparkfun mp3 trigger v.2 working with a SHARP

GP2Y0D340K distance sensor.

At the moment the mp3 file is triggered when someone gets close to the sensor.

My problem is that I would like to invert this: A sensor is at all times blocked by a window. When someone opens the window the mp3 files starts playing.

I only have the sensor and the mp3 trigger. I don’t have time to build anything new or use a different sensor whereas I’m stuck at a museum with a deadline tomorrow.

If you can help me I hope for a quick reply!

Thanks!

  • Jesper
2

jesperhs,

I’m going to ignore your statement “I don’t have time to build anything new or use a different sensor whereas I’m stuck at a museum with a deadline tomorrow.”, as it is contrary to your declared purpose. There are some very knowledgeable and talented people in this forum, but I doubt any of us can change the behavior of electronic apparatus by sheer force of will.

(BTW, I recommend you read [this guide, a link to which our moderator posted in another thread.)

I’m a bit limitted because you haven’t specified which way the window moves or how someone opens it, so I can’t get a good mental picture. That said, here are several ideas you might try:

  • - Instead of using that sensor, use a switch that detects when the window is moved to its open position.

  • - Move the sensor so that it detects the window in its open position.
  • - Move the sensor so that it detects a person's hand on the window handle (if this works like an old-fashioned car window with a crank handle, for example).
  • - Change the position, orientation, or angle of view of the sensor so that the window keeps it from sensing a person. It may, for example, be possible to have such a shallow angle between the sensor's line of sight and the window that the window deflects enough of the IR beam to keep the sensor from detecting a person.
  • - There is mention in the [[datasheet](http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp2y0d340k_e.pdf) of the lens being moved to adjust the sensor, but I didn't see instructions for that. You might, however, do a bit of web searching on that topic.
  • - Coat the window with an IR-dispersive or IR-opaque film, so that it does not allow enough reflection through it for the sensor to detect a person. That way, a person would be sensed only if the window is removed from the path.
    • ](http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp2y0d340k_e.pdf)

    Good Luck,

    Eric](How To Ask Questions The Smart Way)