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Newbie Question: Sound Recording and Playback?? — Parallax Forums

Newbie Question: Sound Recording and Playback??

daelandaelan Posts: 3
edited 2008-09-16 12:45 in Propeller 1
So I just recently purchased my first propeller chip and used it to build the PixelMusic3000. I've yet to really look at the code and haven't tried programming in spin. Basically, I am completely in the dark when it comes to Propellers. However, I am a senior in EET at Purdue University and I am quite familiar with Atmels, so programming isn't too foreign to me. And as far as audio processing goes, I took a DSP class last semester, so I've got the basics of that down.

Anyway, I'm working on my senior design and I'm hoping to make a drum sequencer. The biggest headache im having is finding a reliable solution to recording and playing back audio samples. So here's my question. Can the Propeller chip be used to record audio, and store it either in it's own memory, or external memory, and then be used to select a given sound clip and play it back?

Thanks!

Comments

  • SapiehaSapieha Posts: 2,964
    edited 2008-09-14 21:17
    Hi daelan.

    Look at this thread to have some answers

    http://forums.parallax.com/forums/default.aspx?f=25&p=1&m=143976

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Nothing is impossible, there are only different degrees of difficulty.
    For every stuipid question there is atleast one inteligent answer
    If you dont ask you wont know

    Sapieha
  • RaymanRayman Posts: 14,825
    edited 2008-09-14 21:32
    I've got a wav player in OBEX and a "Parrot" demo code that I posted here that records from microphone and then plays back later over speakers...
  • daelandaelan Posts: 3
    edited 2008-09-14 23:52
    Sapieha

    Thanks! I'm downloading the code now and will give it an extensive look over. I'm sure you will be hearing more from me tongue.gif
    One quick question though, I see that you are sampling at 11k, is that a limitation of the Propeller chip, or simply a choice on your part? Ideally I would like to sample at 44.1k.

    Rayman

    I'm not sure exactly what 'OBEX' means, can you elaborate?

    Post Edited (daelan) : 9/15/2008 12:00:00 AM GMT
  • RaymanRayman Posts: 14,825
    edited 2008-09-14 23:58
    OBEX is "Object Exchange"... A repository on the Parallax.com site for free licensed Propeller code...
  • SapiehaSapieha Posts: 2,964
    edited 2008-09-15 00:08
    Hi daelan.

    It is not my code.
    Write questions on this thread maybe Him that have Thread on answer You more!

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Nothing is impossible, there are only different degrees of difficulty.
    For every stuipid question there is atleast one inteligent answer
    If you dont ask you wont know

    Sapieha
  • daelandaelan Posts: 3
    edited 2008-09-15 00:08
    Ahh i gotcha, thanks =)

    Sorry for shooting so many questions out, but im sitting here in open lab and they keep coming as i dig for more information.

    External memory, is it possible? I'd like to be able to record sound clips to set memory chunks, and then play them back. Does one type of external memory (USB, SD, etc...) work better/is easier to integrate?

    Also, I only have a single Propeller chip, I don't have the Hydra kit or the demo kit, is all of this still possible?
  • SapiehaSapieha Posts: 2,964
    edited 2008-09-15 00:11
    Hi daelan.

    No problem.
    Best choice is SD

    Ps. Simple to conect to Propeler

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Nothing is impossible, there are only different degrees of difficulty.
    For every stuipid question there is atleast one inteligent answer
    If you dont ask you wont know

    Sapieha
  • VIRANDVIRAND Posts: 656
    edited 2008-09-16 04:51
    I plan to write a Propeller SD "tape recorder emulator" sooner or later.
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2008-09-16 12:45
    VIRAND said...
    I plan to write a Propeller SD "tape recorder emulator" sooner or later.

    Funny you should say that. I am already in the final stages of a solid-state cassette recorder/player design which I'm committed to have units within the next few weeks. This unit is basically driven straight off the prop, no codecs, no mp3 decoders, just a running a couple of sigma-deltas at different resolutions/rates and banging that straight onto an SD card. The playback uses something similar where multiple duty-cycle RC outputs are combined. So theoretically I combine fast sample rates and low resolution with low sample rates and high resolution. Not sure if I will get it right the first time but it allows for some flexibility.

    So the idea is that it's a simple little black box with play/rec/rewind/forward controls and definitely no display or complicated menu to work around. The only exception is an A/V output so a TV could be used for speakers and status display. I had been hoping to use mp3 recorders but the menu systems on them are abysmal to say the least, it's a real chore just to get them to record (who designs them?).

    One variation of this design is a full keypad for direct playback of track numbers but it's exactly the same pcb and software though.

    I will try to post the details when it's done but no guarantees as I get stretched in many different directions.

    *Peter*
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