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Digital volume control

ArchiverArchiver Posts: 46,084
edited 2001-10-19 19:05 in General Discussion
Does anybody knows how to work out a digital volume control (with +/- for
vol control instead of knob) as seen in todays digital AV equipment?

John Leung

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2001-10-18 09:32
    Hi John,

    This normally is achieved (when not embedded) by digital resistors as from
    Maxim/Dallas
    DS1867: Dual Digital Potentiometer with EEPROM
    http://pdfserv.maxim-ic.com/arpdf/DS1867.pdf
    DS1868: Dual Digital Potentiometer Chip
    http://pdfserv.maxim-ic.com/arpdf/DS1868.pdf
    These chips can be operated using pushbuttons or of cource a mcrocontroller
    such as stamp.
    The resistor then replaces the normal volume control resistor.

    Regards peter

    Oorspronkelijk bericht
    Van: John Leung [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=x3x2gGBP83sb0A41sf5uZOqYEFwk96bUsscuyyJDt6bcaYkSbzR1XrmNim-8pFBxnRrp7GjXl9JCVMUXqA]jleung00@n...[/url
    Verzonden: donderdag 18 oktober 2001 8:38
    Aan: basicstamps@yahoogroups.com
    Onderwerp: Re: [noparse][[/noparse]basicstamps] Digital volume control

    Does anybody knows how to work out a digital volume control (with +/- for
    vol control instead of knob) as seen in todays digital AV equipment?

    John Leung





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  • ArchiverArchiver Posts: 46,084
    edited 2001-10-18 09:33
    Couple of way off the top of my head. (I haven't implemented any of those
    yet).

    IC's are available that take a serial data stream and do basically
    everything a preamp would - volume, tone controls, balance, fade (if f&r),
    sometimes input selection also.

    I believe they can be expensive, but you can salvage them from car audio
    equipment sometimes. (At least one) Alpine uses one that is programmed
    using I2C.

    Other way is voltage controlled amplifier - the way you produce the control
    voltage is entirely up to you.

    Another way I guess would be to use digital resistor ICs in a conventional
    audio pre amp.

    I'm sure there are other ways and others will comment.

    Luke.

    On Thu, 18 Oct 2001, John Leung wrote:

    M> Does anybody knows how to work out a digital volume control (with +/- for
    M> vol control instead of knob) as seen in todays digital AV equipment?
    M>
    M> John Leung

    --
    '80 (ex)KE38 '86 ST141 '84 AE86 '90 ST185
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-18 19:19
    On Thu, 18 Oct 2001, Luke Szymanski wrote:

    >
    > Another way I guess would be to use digital resistor ICs in a conventional
    > audio pre amp.

    Could you say something more about this? I actually looked for a
    digitally-controlled pot at one point and didn't really find anything.


    Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
    Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
    email: lamont@a... WWW: http://www.serv.net
    "...There's no moral, it's just a lot of stuff that happens". - H. Simpson
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-19 05:38
    On Thu, 18 Oct 2001, Sean T. Lamont .lost. wrote:

    M> On Thu, 18 Oct 2001, Luke Szymanski wrote:
    M>
    M> >
    M> > Another way I guess would be to use digital resistor ICs in a conventional
    M> > audio pre amp.
    M>
    M> Could you say something more about this? I actually looked for a
    M> digitally-controlled pot at one point and didn't really find anything.

    Hi,

    Peter posted the msg below. You need to serially shift in 17 bits for each
    volume change. You could probably build a discrete IC circuit to do that
    shifting, or just use a single microcontroller (I'm not exactly sure what
    Peter meant by "can be operated using pushbuttons"; pushing a button 17
    times is not exactly convenient for the finished product [noparse]:)[/noparse]).

    I didnt know about these specific IC's, wonder how well they'll do in the
    tone control circuits also [noparse]:)[/noparse] I will be trying them in the next few weeks
    as they seem to be the easiest things to use in an existing amplifier.

    Luke.

    On Thu, 18 Oct 2001, peter verkaik wrote:

    M> Hi John,
    M>
    M> This normally is achieved (when not embedded) by digital resistors as from
    M> Maxim/Dallas
    M> DS1867: Dual Digital Potentiometer with EEPROM
    M> http://pdfserv.maxim-ic.com/arpdf/DS1867.pdf
    M> DS1868: Dual Digital Potentiometer Chip
    M> http://pdfserv.maxim-ic.com/arpdf/DS1868.pdf
    M> These chips can be operated using pushbuttons or of cource a mcrocontroller
    M> such as stamp.
    M> The resistor then replaces the normal volume control resistor.
    M>

    --
    '80 (ex)KE38 '86 ST141 '84 AE86 '90 ST185
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-19 05:59
    Hi Luke,

    What I meant with pushbuttons, is that there are digital resistors (from
    Xicor I believe) that have
    pulse up and pulse down inputs. Whenever a pulse is received on these input
    pins the resistor
    increments or decrements by 1 position. I didn't check the Maxim specs, just
    passed
    along the links.

    Regards peter


    Oorspronkelijk bericht
    Van: Luke Szymanski [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=XJbjuV8dRXogVKr8hyNgIuM2BwQxmBfTuMirMtjuBRhPOha_6wQPRm29Nt6gUxquJz_po2M34wJ2_bZs]lsz@c...[/url
    Verzonden: vrijdag 19 oktober 2001 5:38
    Aan: basicstamps@yahoogroups.com
    Onderwerp: Re: [noparse][[/noparse]basicstamps] Digital volume control

    On Thu, 18 Oct 2001, Sean T. Lamont .lost. wrote:

    M> On Thu, 18 Oct 2001, Luke Szymanski wrote:
    M>
    M> >
    M> > Another way I guess would be to use digital resistor ICs in a
    conventional
    M> > audio pre amp.
    M>
    M> Could you say something more about this? I actually looked for a
    M> digitally-controlled pot at one point and didn't really find anything.

    Hi,

    Peter posted the msg below. You need to serially shift in 17 bits for each
    volume change. You could probably build a discrete IC circuit to do that
    shifting, or just use a single microcontroller (I'm not exactly sure what
    Peter meant by "can be operated using pushbuttons"; pushing a button 17
    times is not exactly convenient for the finished product [noparse]:)[/noparse]).

    I didnt know about these specific IC's, wonder how well they'll do in the
    tone control circuits also [noparse]:)[/noparse] I will be trying them in the next few weeks
    as they seem to be the easiest things to use in an existing amplifier.

    Luke.

    On Thu, 18 Oct 2001, peter verkaik wrote:

    M> Hi John,
    M>
    M> This normally is achieved (when not embedded) by digital resistors as
    from
    M> Maxim/Dallas
    M> DS1867: Dual Digital Potentiometer with EEPROM
    M> http://pdfserv.maxim-ic.com/arpdf/DS1867.pdf
    M> DS1868: Dual Digital Potentiometer Chip
    M> http://pdfserv.maxim-ic.com/arpdf/DS1868.pdf
    M> These chips can be operated using pushbuttons or of cource a
    mcrocontroller
    M> such as stamp.
    M> The resistor then replaces the normal volume control resistor.
    M>

    --
    '80 (ex)KE38 '86 ST141 '84 AE86 '90 ST185




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  • ArchiverArchiver Posts: 46,084
    edited 2001-10-19 06:10
    Hi,

    I was right about Xicor. They have digital resistors with simple up/down
    control.
    See the folowing selection guide.
    http://www.xicor.com/product_select_guide.php?table=xdcp

    regards peter


    Oorspronkelijk bericht
    Van: Luke Szymanski [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=JV5MqtT2WYrkR1loIhAZF4K4lRHjwkQqqbAceAlwK6fu3fC9eDg4Gq1eWlnaMbgtBUreXohQWAeIBMgchQ]lsz@c...[/url
    Verzonden: vrijdag 19 oktober 2001 5:38
    Aan: basicstamps@yahoogroups.com
    Onderwerp: Re: [noparse][[/noparse]basicstamps] Digital volume control

    On Thu, 18 Oct 2001, Sean T. Lamont .lost. wrote:

    M> On Thu, 18 Oct 2001, Luke Szymanski wrote:
    M>
    M> >
    M> > Another way I guess would be to use digital resistor ICs in a
    conventional
    M> > audio pre amp.
    M>
    M> Could you say something more about this? I actually looked for a
    M> digitally-controlled pot at one point and didn't really find anything.

    Hi,

    Peter posted the msg below. You need to serially shift in 17 bits for each
    volume change. You could probably build a discrete IC circuit to do that
    shifting, or just use a single microcontroller (I'm not exactly sure what
    Peter meant by "can be operated using pushbuttons"; pushing a button 17
    times is not exactly convenient for the finished product [noparse]:)[/noparse]).

    I didnt know about these specific IC's, wonder how well they'll do in the
    tone control circuits also [noparse]:)[/noparse] I will be trying them in the next few weeks
    as they seem to be the easiest things to use in an existing amplifier.

    Luke.

    On Thu, 18 Oct 2001, peter verkaik wrote:

    M> Hi John,
    M>
    M> This normally is achieved (when not embedded) by digital resistors as
    from
    M> Maxim/Dallas
    M> DS1867: Dual Digital Potentiometer with EEPROM
    M> http://pdfserv.maxim-ic.com/arpdf/DS1867.pdf
    M> DS1868: Dual Digital Potentiometer Chip
    M> http://pdfserv.maxim-ic.com/arpdf/DS1868.pdf
    M> These chips can be operated using pushbuttons or of cource a
    mcrocontroller
    M> such as stamp.
    M> The resistor then replaces the normal volume control resistor.
    M>

    --
    '80 (ex)KE38 '86 ST141 '84 AE86 '90 ST185




    To UNSUBSCRIBE, just send mail to:
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  • ArchiverArchiver Posts: 46,084
    edited 2001-10-19 12:33
    John,
    Take a look at Jameco Electronics part # 173024. It is a digital volume
    control chip with two channels and pushbutton control. I just completed
    a project using one of these with some ISD chipcorders feeding to the
    volume IC and then to a LM386 amplifier. The whole thing (volume,
    start/stop, and sound selection) is controlled by a remote control using
    the Rentron TWS/RWS 434 remote products. I liked the Princeton volume
    control as it was easy to wire and works well. Let me know if you want
    the pdf data sheet for the volume IC and I will e-mail it to you. Good
    luck!
    Tom

    ________________________________________________________________________
    ________________________________________________________________________

    Message: 11
    Date: Thu, 18 Oct 2001 15:38:14 +0800
    From: "John Leung" <jleung00@n...>
    Subject: Re: Digital volume control

    Does anybody knows how to work out a digital volume control (with +/-
    for
    vol control instead of knob) as seen in todays digital AV equipment?

    John Leung
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-19 13:45
    > Couple of way off the top of my head. (I haven't implemented any of those
    > yet).
    >
    > Other way is voltage controlled amplifier - the way you produce the
    control
    > voltage is entirely up to you.

    If you go with a voltage controlled amplifier, you could then set up a PWM
    routine in the stamp and go through an RC filter to produce the variable
    voltage. Going into the stamp would then be two pushbuttons for +/-. Sounds
    like a neat application for a BS1 or one of the small PIC units.

    Keep in mind that this is only my suggestion as I have not tried this
    either, but logic dictates that this method (along with some other ones)
    should work.

    Cheers,

    Gerry Shand
    gshand@h...

    With enough time, energy and/or money, anything is possible
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-19 19:05
    Thanks Tom, but my computer has some problem such that even though the
    jameco web page is there, I just cannot watch the details for the component
    you have mentioned. But I will try again later. By the way, I also need to
    know if that component is available in my country, otherwise, it takes a
    long way for me to order it.

    John Leung

    Original Message
    From: "TWELLE" <twelle@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Friday, October 19, 2001 7:33 PM
    Subject: RE: [noparse][[/noparse]basicstamps] Digital volume control


    >
    > John,
    > Take a look at Jameco Electronics part # 173024. It is a digital volume
    > control chip with two channels and pushbutton control. I just completed
    > a project using one of these with some ISD chipcorders feeding to the
    > volume IC and then to a LM386 amplifier. The whole thing (volume,
    > start/stop, and sound selection) is controlled by a remote control using
    > the Rentron TWS/RWS 434 remote products. I liked the Princeton volume
    > control as it was easy to wire and works well. Let me know if you want
    > the pdf data sheet for the volume IC and I will e-mail it to you. Good
    > luck!
    > Tom
    >
    > ________________________________________________________________________
    > ________________________________________________________________________
    >
    > Message: 11
    > Date: Thu, 18 Oct 2001 15:38:14 +0800
    > From: "John Leung" <jleung00@n...>
    > Subject: Re: Digital volume control
    >
    > Does anybody knows how to work out a digital volume control (with +/-
    > for
    > vol control instead of knob) as seen in todays digital AV equipment?
    >
    > John Leung
    >
    >
    >
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
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