Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 15 of 15

Thread: Novice questions about sound-reactive wearable project

  1. #1

    Novice questions about sound-reactive wearable project

    Hi!

    I am looking to build yet-another sound-reactive wearable project (t-shirt with leds) for upcoming trance music festival :-)
    This is my first experience with Arduino's or microelectronics at all. No wonder I have a list of questions I need to find answers for to build it. I am trying to research it myself as well as I could but sometimes, being a novice, I have to ask others.

    So, maybe you could give me some input about what microphone should I choose? It seems they all not that expensive so lets try to rule out price. I need a good resolution for doing FFT, low noise and it must work in a loud settings (festival after all...). Generally - best quality small-size microphone :-)
    Most probably I would be using Teensy 3.2 with it. Amazing possibilities for its price, size and power requirements!

    At least at what specs should I look? Electret, mems, other type? Maybe "big" one like lavalier would work even better?

  2. #2
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    20,097
    Probably best to start with the normal electret mic and the audio shield.

    http://www.pjrc.com/store/microphone.html

    For use in a wearable project, especially worn while dancing at a festival, the way to position the mic will make far more difference than the type of mic. Even these cheapest electret ones will have a noise floor that's far less than the noise you'll pick up from ruffling of clothes & costumes.

  3. #3
    Hm, can't found SPL acoustic overload point of this mic. I am afraid that sound about ~120dB will be too much for it...
    https://www.tindie.com/products/oneh...al-microphone/ looks much more promising. And I won't need Audio Board for it, right?

    Thank you for input about ruffling and all! Didn't thought about it.

  4. #4
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    20,097
    I do not know if that mic works with the audio lib. It might, or it might need a longer than 16 bit word format. The page says 24 bits. I can tell you the I2S code we have now uses 16 bits per LRCLK phase, not 24 or 32.

    To get started, I recommend the well traveled path of the audio board and electret mic. You can always try to switch to a different mic later. By then, you'll have gained quite a lot of experience with the rest of the project, which should make these decisions clearer.

  5. #5
    Oh. Not so promising then!

    I will follow your advice. So, Teensy, Audio board, two 14x1-D pins and microphone?

    edit: um, my time requirements and your shipping prices are quite incompatible it turns out! I've ordered Teensy and Audio board from another seller. No double insulator pins though... I'll think up something :-)
    Last edited by skaurus; 07-19-2016 at 03:07 PM.

  6. #6
    Hello again.

    Does 3.5" input jack on Audio board have "Plug in Power"? It is required for some external microphones.
    Also it may be useful to know - is this jack wired OMTP way or CTIA / AHJ way?
    Last edited by skaurus; 08-03-2016 at 04:23 PM.

  7. #7
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Location
    Ayer Massachussetts
    Posts
    2,960
    Note, the 3.5" jack on the audio board is an output jack for sound output to headphones. There are line in pins and pins for a microphone, but these don't include a power pin.

  8. #8
    Thanks for your reply.

    Oh. So to connect some external microphone I will have to solder appropriate jack?

  9. #9
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Location
    Ayer Massachussetts
    Posts
    2,960
    Quote Originally Posted by skaurus View Post
    Thanks for your reply.

    Oh. So to connect some external microphone I will have to solder appropriate jack?
    Yes, or at least solder wires to connect to the microphone. There is a microphone input/ground in the center of the board, plus left/right line-in pins on one side. I would imagine you could also hook up an i2s microphone to the audio shield.

    If you wanted a basic microphone, PJRC sells one with a little custom washer that is made for the audio shield: http://www.pjrc.com/store/microphone.html

    Onehorse makes a i2s microphone that is meant to attach to a Teensy, but I don't know if it would work with the audio shield: https://www.tindie.com/products/oneh...ll_prod_search.

  10. #10
    Senior Member+ defragster's Avatar
    Join Date
    Feb 2015
    Posts
    8,614
    @MM - the onehorse i2s mic was noted above p_3 - it is 24 bits ...

    Question: The MIC section I assume has a suitable amp circuit to support the electret mic? What levels are 'line in'? My limited understanding suggests the line in would expect something driven to the level of a 'Mic on a breakout' with needed pre-amplification?

    Also not sure if I read this right - but was it once stated - in this context - that the headphone output shouldn't be put into a amplifier system of a typical pc speaker system type arrangement?

  11. #11
    Quote Originally Posted by MichaelMeissner View Post
    If you wanted a basic microphone, PJRC sells one with a little custom washer that is made for the audio shield: http://www.pjrc.com/store/microphone.html
    Well, I had to order Teensy from another store and they didn't have this mic.
    And then I found that for most of the mics I could buy near me (I'm outside of the USA) I can't even find datasheet.
    Maybe I just don't know proper stores here, but anyway, I wasn't bothered much since I was going to use lavalier microphone with mini jack (1⁄8 in) for better quality.

    Now, it turns out, it isn't so simple :-) Can you confirm that I can (or can't) solder mini jack to line in R + L + 2xG pins and connect external microphone to it? Will it work or I will need some kind of amplifier or what else? If yes (I hope so!) maybe you can explain what solder to what? I find it hard to find microphone jack pinout

    Quote Originally Posted by MichaelMeissner View Post
    Yes, or at least solder wires to connect to the microphone. There is a microphone input/ground in the center of the board, plus left/right line-in pins on one side. I would imagine you could also hook up an i2s microphone to the audio shield.
    I guess MIC+GND pins are for microphones like from PRJC store only, not for "big" ones with mini jack?

    Quote Originally Posted by MichaelMeissner View Post
    Onehorse makes a i2s microphone that is meant to attach to a Teensy, but I don't know if it would work with the audio shield: https://www.tindie.com/products/oneh...ll_prod_search.
    Yeah, I know... Maybe it was a mistake to not order it at the same time as Teensy and now I can't - due to my project time restrictions :-(

  12. #12
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Location
    Ayer Massachussetts
    Posts
    2,960
    Somebody who knows the electronics more than me will have to answer those questions.

  13. #13
    Thanks anyway

  14. #14
    Maybe I can solder microphone audio jack directly to MIC+GND pins and it will work?

  15. #15
    Maybe I can solder microphone audio jack directly to MIC+GND pins and it will work?
    Yes! I soldered audio jack, inserted microphone in and it works!
    And pretty well :-)
    Cheap random lavalier model: Panasonic RP-VC201

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •