Doing bat detection

Discussion in 'The Projects Forum' started by saharsahar, Aug 16, 2010.

  1. saharsahar

    Thread Starter New Member

    Aug 16, 2010
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    does anybody knows if I can use microcontroller for bat detection (and then species recognition), if so , what kind of microcontroller and microphones(equiopment) I need?
    thanks so much
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Bat as in the flying vampire creatures?
    Sure pretty much any microcontroller can be used...
    The tougher part is finding a microphone capable of hearing those sounds and then building the circuitry to convert that microphone signal into one that the micro can tolerate.
    Of course this is assuming a bats frequency/sound pattern is unlike no other animal as then you might pick up on other creatures besides bats

    I have no idea on species recognition as I have no idea how you tell one species from the other... If you can tell us how one would tell one species from the other you could get a better answer. By look/sound/smell???
     
  3. beenthere

    Retired Moderator

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    The species echolocation pulses are identifiable in both duration and frequency range. PRF changes as the animals track prey insects.

    The link is to a site with a lot of useful links - http://www.batbox.org/
     
  4. saharsahar

    Thread Starter New Member

    Aug 16, 2010
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    thanks mcgyvr. As "beenthere" mentioned the bat species recognistion will be done by analysis on the signals(frequency/time) which we got from the bar recording.
    but for first step which is preparing the equipments for recording, I'm not very sure which one is a better choice with reaonable price . using microcontroller as one option, I found out EK-3132 or CA-2833 microphone detects the ultrasound bat calls. but for mirocontroller , I really don know which type supports the ultrasound signals.
    any suggestion is appereciated , even allowing me if i'm in the right track.
     
  5. andreapg

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  6. retched

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    You may want to look into MICROCHIPs dsPIC or other companies DSP (digital signal processing) micros.

    They are built for signal processing and would handle audio processing and FFT or other processing types, frequency counting, etc.. much faster and with less power than standard, non-DSP, micros.

    Most have on-board ADCs (analog to digital converters) of 10 or more bits that will allow you to connect to an ultrasonic mic or transducer that can 'hear' the sounds.

    It would be up to you to put the code together to sample the sound, then do the proper frequency counting and analysis to determine species and such.

    I think it would be neat.

    You could do a simple look-up table to give the results..ie:
    50kHz to 66khz is a WingedDracula
    66.1kHz to 77kHz is a Mohawked Fruit Bat

    etc..etc...

    The responses could be recorded via SD card and/or displayed on a LCD display. The sampled audio could also be recorded for later playback and analysis.
     
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  7. saharsahar

    Thread Starter New Member

    Aug 16, 2010
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    Thanks retched for your precise answer. I prefer Atmel rather than microchip as I found Atmel provide better chips than microchip. but my problem is that as I'm a beginner with microcontroller , I'm not sure which one is good. would you please suggest one, which has a 10 bit ADC and supports ultrasound microphone as well. in addition , I wanna it to be on a board not just the microcontroller.
    I really appereciate your kindness for helping me.
     
  8. saharsahar

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    Aug 16, 2010
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    In fact I want to introduce me a board( the model) with ADC and microcontroller which from one side connects to ultrasound microphone and the other side to PC or remotely controled(wireless0. any suggestion or recommendation is highly appereciated.
    sahar
     
  9. radiohead

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    May 28, 2009
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  10. bertus

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    Apr 5, 2008
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    Hello,

    In this thread there are also links about bat detectors:
    Bat detector design

    Bertus
     
  11. tom66

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    May 9, 2009
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  12. saharsahar

    Thread Starter New Member

    Aug 16, 2010
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    thanks all for your help.
    I still have a stupid question. according to my advisor I have make an embedded system for this work.(bat detector), does it mean the same meaninig of and ADC and micro controller on a board, or do I need extra equipment. is it itself ( ADC and microcontroller on a board) mean an embedded system or it should be placed in another device?
    thanks again,
    sahar
     
  13. rogs

    Active Member

    Aug 28, 2009
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    Not that well they don't! - too limited frequency range.
    You may need to look at something more suitable, like these : http://www.knowles.com/search/prods_pdf/SPM0404UD5.PDF
    for example.

    I'm guessing that with the expertise available from the forum members here, you'll get some good advice on how to 'didgitise' your bat calls, with an appropriately fast ADC, and and microcotroller.
    But that's only going to make any sense at all if your sensor -and sensor preamp - is any good.

    You might even find it easier to look at recording your bat calls using one of the solid state audio recorders with an extended frequency range -(like the Korg MR1:http://www.korg.com/product.aspx?pd=284) and then import those recordings for analysis?
    Again, you'll need to build a decent ultrasonic sensor and preamp to get any useful results.

    Not an easy project (I know, I've tried!). Probably explains why the advertised scientific equipment for this kind of thing is so expensive!
     
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  14. beenthere

    Retired Moderator

    Apr 20, 2004
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    Looking at a link from an earlier post, I came across an inexpensive detector - http://www.econvergence.net/batdet.htm

    The device uses a simple technique to shift the bat echolocation calls into the human range of frequencies. With the audio jack output, just about any computer could record and make a file using the sound card.

    That may be making an assumption that the frequency shift is the same across the range of the instrument. That is simple enough to test by presenting the microphone with a few ultrasonic tones and determining the resulting frequency at the output. If they all get shifted alike, then it's simple to assign a multiplier value to tell the received call frequency.
     
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  15. saharsahar

    Thread Starter New Member

    Aug 16, 2010
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    thanks beenthere and rogs. the detector seems intresting. I will think of it in deep.
    as an microcontroller way, does anybody knows PIC40x2 (aka 18F4520) if support ultrasound to digital converter and what is the software for this microcontroller. I searched many websites but at last I didn't finf the software for this microcontroller.
    Thanks a lot.
     
  16. beenthere

    Retired Moderator

    Apr 20, 2004
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  17. saharsahar

    Thread Starter New Member

    Aug 16, 2010
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    Thanks all .
    Now , I face a new problem in building my own bat detector. as you may know different techniques like frequency Division, Time expanded and Heterodyning can be used in bat detection. However I found that Time Expandedis the best one with higher precision. but I heard another technique as "Direct Recording " that I can not understand how doea it work. Does it mean that it doen't require the Analoge to digital converter or what? If anybody know about this technique , I really appereciate if help me to know about it. The only things that I ask and get answer from any bat detector designer , is that " it works with full spectrum" but not more explain.
    Thanks .
     
  18. saharsahar

    Thread Starter New Member

    Aug 16, 2010
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    Hi all,
    Does anybody have any idea of how I can get a library for bat calls ?
    thanks
     
  19. retched

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  20. saharsahar

    Thread Starter New Member

    Aug 16, 2010
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    thanks a lot, I got an library of bats which I can download the bat calls for many species. but one of the bat species which is in the endanger list and I must include it in my library is " Myotis Sodalis" or as a common name" Indiana bat".unfortunately I couldn't find its call.
    Does anybody have the calls for this species or know how I can access it?
    Thanks a lot,
    Sahar
     
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