Connect with us

Recording and repeating voltages

Discussion in 'General Electronics Discussion' started by darren adcock, Feb 3, 2018.

Scroll to continue with content
  1. darren adcock

    darren adcock

    463
    34
    Sep 26, 2016
    Hi all. I've been trying to research how to record and repeat sequences of voltages to no avail.

    What I want to be able to do is; use piezo discs and a signal conditioning circuit (courtesy of you guys a while back) to pick up vibrations from an area. then have a way of recording these and be able to repeat them in exactly the same way

    I use the sensors to modulate parts of my synthesizer. However with the growth of my synth it's getting less feasible to take it to the field. So being able to record and repeat would be a huge help.

    Thanks in advance

    Darren
     
  2. Alec_t

    Alec_t

    2,909
    791
    Jul 7, 2015
    That's a job for a MCU. Condition the signals to be within the allowed analogue input range of the MCU, use an A-to-D converter in the MCU to get digital values, store the digital values for later conversion back to analoge by a D-to-A converter. Can you program an MCU?
     
    darren adcock likes this.
  3. kellys_eye

    kellys_eye

    4,275
    1,146
    Jun 25, 2010
    DAQ - Digital Acquisition. There are some projects around that offer analog/digital recording onto SD card in multi-channel ways but there are limitations in every system based on sample rate and length of recording although, theoretically, you could do this ad infinitum.

    In a most basic form you could use those digital voice record/playback modules for short sample periods but without knowing your full spec requirement we can't be more specific.
     
    darren adcock likes this.
  4. darren adcock

    darren adcock

    463
    34
    Sep 26, 2016
    HI folks I've never used a microcontroller or programmed one. I have however done quite a lot of coding in my past.

    However I have no idea how to interface with a microcontroller even if i could write a programme for it... I have an arduino Kit somewhere which i've never looked at.... maybe this is the time to open that up

    Full spec:

    I'll try to address this here

    Control voltage range is nearabouts -8v to +8v.... it's meant to be 5 either side but I've not ran into problems yet.

    length of recording..... I think I'd like up to 20 mins for now... but to be honest even a minute would be a huge help

    It would need to run also from a portable power source... at the minute I have AA batteries, which is rubbish..... but upgrading to LIPO soon


    Thanks for replies and I'll follow your leads

    Best

    Darren
     
    Last edited: Feb 4, 2018
  5. Harald Kapp

    Harald Kapp Moderator Moderator

    10,808
    2,438
    Nov 17, 2011
    Recording and repeating a sequence of voltages is everyday business in music.

    Any audio recorder can record the signals as long as the frequency is within the audio range and the amplitude is scaled to match the input range of the recorder.
    The audio can be played back to reconstruct the sequence of voltages and these can be amplified to (almost) any level required.

    Use for example the soundcard input/output of your PC. Use your smartphone if it needs to be portable. Plus an amplifier for the +-8 V amplitude required.
     
    darren adcock likes this.
  6. Alec_t

    Alec_t

    2,909
    791
    Jul 7, 2015
    Be aware that sound cards may have a frequency response that drops sharply below about 20Hz.
     
  7. darren adcock

    darren adcock

    463
    34
    Sep 26, 2016
    Ahhhhhh thanks Harald. I can even begin work on this tomorrow.

    Cheers

    Darren
     
  8. Harald Kapp

    Harald Kapp Moderator Moderator

    10,808
    2,438
    Nov 17, 2011
    That surely is a limitation to be taken into account, as well as the frequency response above 15 kHz ... 20 kHz.
     
  9. darren adcock

    darren adcock

    463
    34
    Sep 26, 2016
    I can use my field recorder ( it has 4 tracks) and auto levels function which i've used a lot with piezo discs.
     
  10. Harald Kapp

    Harald Kapp Moderator Moderator

    10,808
    2,438
    Nov 17, 2011
    You may want to turn off the auto level function to better record the varying levels of voltage from the piezo sensors.
     
  11. darren adcock

    darren adcock

    463
    34
    Sep 26, 2016
    Ok, Cheers Harald.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-