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Build a simple bat detector


[Tony Messina] had been fascinated with bat’s echolocation since he was a kid. After he retired, he decided to act on this fascination and built a simple bat detector.

The simple bat detector uses frequency division to lower the bat’s chirping to a frequency we can hear. For example, if a bat is calling at 91kHz the system will divide it by 16 and put out 5.7kHz. The system is digital, so all amplitude is lost. You’ll just hear clicks like a Geiger counter. Being digital has its advantages though. Unlike similar analog devices that have to be tuned to a small frequency range, the simple bat detector can detect a much wider window.

[Tony] has supplied step by step directions on how to assemble the simple bat detector, along with plans for two different models. He not only encourages people to build there own, but seems to really enjoy seeing their work. He’s posted several images of other people’s builds (pictured above) on his site.

[suneth] has taken this idea in a slightly different direction with his Ultrasonic Batgoggles. Built for a school project in Arts, Media, and Engineering, they actually block your vision so you can try to use echolocation to navigate. You don’t hear the echoes, the processor deciphers that for you. You hear a beep that varies in speed based on the distance you are from an object. On the plus side, you will look totally awesome wandering around trying not to bash your nose on stuff.

[via only hacks]

Comments

  1. BigD145 says:

    damn. i just stick my head out the door. if a bat is doing the sonar bounce off my head, i hear it.

  2. zish says:

    It’d be more fun to have a “bat pranker”. I can just picture several output channels, each with a speaker placed around the yard. Our listener waits for bat signals, and echoes back the signal from any number of the channels at random.
    The bat would be all like, WTF!?
    And I’d be like hahaha!
    Then the bat would be like FU!
    Then he’d give me rabies.

  3. Scott says:

    Just the thing for constructing a bat detector van.

    “How much did you pay for this?”
    “Sixty quid, and eight for the fruit-bat.”

  4. jimmys says:

    I just built one of the ‘enhanced’ models about a week ago. very simple but very capable. I’ll probably end up adding variable resistors for gain and a multi position switch for the different frequency divisions but the design works well without them.

    I’m not a big fan of the earphone/power switch trick, though. It’s a neat idea but if I leave my headphones on when I plug in, I get a loud pop which is annoying.

    I haven’t had it long enough to have detected any actual bats but there’s been enough things that emit ultrasonic frequencies to keep me amused. I’m wondering if it might be useful as a crude diagnostic device to listen to capacitors charging.

  5. Wolf says:

    This was up on miked’s onlyhacks.com a couple of days ago…

    lol

  6. Alex Dodge says:

    Watching the video first, I thought it was processing sonar into a visual display.

    Reality is a bit of a letdown.

  7. miked says:

    come on now! i found the bat detector and posted on 7/31.

    http://onlyhacks.com/2008/07/31/diy-bat-detector/

    if you are going to copy at least give some credit.

  8. Eliot says:

    @miked sorry about that. Every so often the via gets lost. I added it to the post.

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