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BCD to binary converter — Parallax Forums

BCD to binary converter

ArchiverArchiver Posts: 46,084
edited 2004-02-18 17:01 in General Discussion
I need my basic stamp to control 16 different lights, so I figure
that I could just use 4 pins on the stamp to control a 4-digit BCD-to-
binary converter, which would mean I would use 12 less output pins on
the stamp. But I'm having trouble finding a BCD-binary chip.

Does anyone have any good suggestions for a BCD-binary chip?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-02-18 14:43
    What you want is a 74LS154 which is a 4 to 16 decoder.

    This is not technically BCD, by the way (I resisted the urge to say BCD,
    BTW).

    Regards,

    Al Williams
    AWC
    *NEW Kits: http://www.awce.com/kits.htm


    Original Message
    From: andy_watson5 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=BoLZoA7CUTtHYP7rX1WdjFzgtukhGa1w_kMllM73nK-_WUEB5uJADkg-4s5ygI5sy3oUKcE-0cc63XWg]andywatson@m...[/url
    Sent: Wednesday, February 18, 2004 8:30 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] BCD to binary converter


    I need my basic stamp to control 16 different lights, so I figure
    that I could just use 4 pins on the stamp to control a 4-digit BCD-to-
    binary converter, which would mean I would use 12 less output pins on
    the stamp. But I'm having trouble finding a BCD-binary chip.

    Does anyone have any good suggestions for a BCD-binary chip?



    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
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  • ArchiverArchiver Posts: 46,084
    edited 2004-02-18 15:54
    Do you need to have more than one light on at once? Or all off? If yes
    to either question, you might consider using a couple of daisy-chained
    74HC595 shift registers. Using just three pins you can control 16
    outputs in any combination. And if you decide to go to 24 outputs you
    just have to add another '595 to the chain.

    Our StampWorks book shows how to use the 74HC595 with the BASIC Stamp
    and how to string them together.

    -- Jon Williams
    -- Applications Engineer, Parallax
    -- Dallas Office


    Original Message
    From: andy_watson5 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=QvDFhmTPFaveRDL7NHWelIHHIMBu1OZ02cE911zL1vnpoAGBtwBpEMfRJsCNI1h7EvYdw-w0s_qwMO9L2tw]andywatson@m...[/url
    Sent: Wednesday, February 18, 2004 8:30 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] BCD to binary converter


    I need my basic stamp to control 16 different lights, so I figure
    that I could just use 4 pins on the stamp to control a 4-digit BCD-to-
    binary converter, which would mean I would use 12 less output pins on
    the stamp. But I'm having trouble finding a BCD-binary chip.

    Does anyone have any good suggestions for a BCD-binary chip?
  • ArchiverArchiver Posts: 46,084
    edited 2004-02-18 16:21
    Yes, I just looked at the datasheets for the 74154, and I see that it
    only provides 16 mutually exclusive outputs. I will need to control
    the 16 outputs in various combinations, so I'll investigate the
    74HC595. Thanks.

    --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
    wrote:
    > Do you need to have more than one light on at once? Or all off?
    If yes
    > to either question, you might consider using a couple of daisy-
    chained
    > 74HC595 shift registers. Using just three pins you can control 16
    > outputs in any combination. And if you decide to go to 24 outputs
    you
    > just have to add another '595 to the chain.
    >
    > Our StampWorks book shows how to use the 74HC595 with the BASIC
    Stamp
    > and how to string them together.
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Dallas Office
    >
    >
    >
    Original Message
    > From: andy_watson5 [noparse][[/noparse]mailto:andywatson@m...]
    > Sent: Wednesday, February 18, 2004 8:30 AM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] BCD to binary converter
    >
    >
    > I need my basic stamp to control 16 different lights, so I figure
    > that I could just use 4 pins on the stamp to control a 4-digit BCD-
    to-
    > binary converter, which would mean I would use 12 less output pins
    on
    > the stamp. But I'm having trouble finding a BCD-binary chip.
    >
    > Does anyone have any good suggestions for a BCD-binary chip?
  • ArchiverArchiver Posts: 46,084
    edited 2004-02-18 16:29
    Probably overkill, but you could always use a BS2P/40 or add a PAK-IV to get
    16 outputs. In both cases, the extra pins would have more functions,
    although in your case you probably don't care. Also with the PAK-IV you can
    get some concurrency as the PAK does one operation and the Stamp does
    another. Probably not important in this case though.

    Now if you want to dim the lights... the PAK-Vc will handle 8 lights per
    chip and you can gang them to drive a large number of outputs.

    Regards,

    Al Williams
    AWC
    *New Universal PCB for any Basic Stamp
    http://www.awce.com/asp3.htm


    Original Message
    From: andy_watson5 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ih93-Vc_EINTqfRzHrP4J2RDoOOm1u8hSZ1XkOSfZHthfaJL7jGj24HUSSQ2h9-pP5dkT95DBOyTUM_QKw]andywatson@m...[/url
    Sent: Wednesday, February 18, 2004 10:22 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Re: BCD to binary converter


    Yes, I just looked at the datasheets for the 74154, and I see that it
    only provides 16 mutually exclusive outputs. I will need to control
    the 16 outputs in various combinations, so I'll investigate the
    74HC595. Thanks.

    --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
    wrote:
    > Do you need to have more than one light on at once? Or all off?
    If yes
    > to either question, you might consider using a couple of daisy-
    chained
    > 74HC595 shift registers. Using just three pins you can control 16
    > outputs in any combination. And if you decide to go to 24 outputs
    you
    > just have to add another '595 to the chain.
    >
    > Our StampWorks book shows how to use the 74HC595 with the BASIC
    Stamp
    > and how to string them together.
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Dallas Office
    >
    >
    >
    Original Message
    > From: andy_watson5 [noparse][[/noparse]mailto:andywatson@m...]
    > Sent: Wednesday, February 18, 2004 8:30 AM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] BCD to binary converter
    >
    >
    > I need my basic stamp to control 16 different lights, so I figure
    > that I could just use 4 pins on the stamp to control a 4-digit BCD-
    to-
    > binary converter, which would mean I would use 12 less output pins
    on
    > the stamp. But I'm having trouble finding a BCD-binary chip.
    >
    > Does anyone have any good suggestions for a BCD-binary chip?



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  • ArchiverArchiver Posts: 46,084
    edited 2004-02-18 17:01
    Actually, I'm already using a BS2P40. So far I've got 9 inputs and
    22 outputs, which makes 31. So I've only got 1 free I/O, which
    leaves little room for expanding the program/circuit later. I might
    also be able to use 74HC595 shift registers to shrink the number of
    inputs using SHIFTIN as well, but since I'm new to all this BASIC
    stuff, I'm a little overwhelmed right now. Just looking for a simple
    high pulse on a pin is easy. But using shift registers and loading
    data into the stamp just doesn't make sense to me. Maybe if I stare
    at it long enough, I'll understand it.

    Thanks for all the advice guys.

    --- In basicstamps@yahoogroups.com, "Al Williams" <alw@a...> wrote:
    > Probably overkill, but you could always use a BS2P/40 or add a PAK-
    IV to get
    > 16 outputs. In both cases, the extra pins would have more functions,
    > although in your case you probably don't care. Also with the PAK-IV
    you can
    > get some concurrency as the PAK does one operation and the Stamp
    does
    > another. Probably not important in this case though.
    >
    > Now if you want to dim the lights... the PAK-Vc will handle 8
    lights per
    > chip and you can gang them to drive a large number of outputs.
    >
    > Regards,
    >
    > Al Williams
    > AWC
    > *New Universal PCB for any Basic Stamp
    > http://www.awce.com/asp3.htm
    >
    >
    >
    Original Message
    > From: andy_watson5 [noparse][[/noparse]mailto:andywatson@m...]
    > Sent: Wednesday, February 18, 2004 10:22 AM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Re: BCD to binary converter
    >
    >
    > Yes, I just looked at the datasheets for the 74154, and I see that
    it
    > only provides 16 mutually exclusive outputs. I will need to
    control
    > the 16 outputs in various combinations, so I'll investigate the
    > 74HC595. Thanks.
    >
    > --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
    > wrote:
    > > Do you need to have more than one light on at once? Or all off?
    > If yes
    > > to either question, you might consider using a couple of daisy-
    > chained
    > > 74HC595 shift registers. Using just three pins you can control
    16
    > > outputs in any combination. And if you decide to go to 24 outputs
    > you
    > > just have to add another '595 to the chain.
    > >
    > > Our StampWorks book shows how to use the 74HC595 with the BASIC
    > Stamp
    > > and how to string them together.
    > >
    > > -- Jon Williams
    > > -- Applications Engineer, Parallax
    > > -- Dallas Office
    > >
    > >
    > >
    Original Message
    > > From: andy_watson5 [noparse][[/noparse]mailto:andywatson@m...]
    > > Sent: Wednesday, February 18, 2004 8:30 AM
    > > To: basicstamps@yahoogroups.com
    > > Subject: [noparse][[/noparse]basicstamps] BCD to binary converter
    > >
    > >
    > > I need my basic stamp to control 16 different lights, so I figure
    > > that I could just use 4 pins on the stamp to control a 4-digit
    BCD-
    > to-
    > > binary converter, which would mean I would use 12 less output pins
    > on
    > > the stamp. But I'm having trouble finding a BCD-binary chip.
    > >
    > > Does anyone have any good suggestions for a BCD-binary chip?
    >
    >
    >
    > 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.
    >
    > Yahoo! Groups Links
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