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Stamp counting capabilities — Parallax Forums

Stamp counting capabilities

ArchiverArchiver Posts: 46,084
edited 2004-06-11 04:44 in General Discussion
Is it possible to use a stamp as a counter on two inputs at the same
time? I would like to subtract one counter from the other and not
miss any counter pulses.

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-06-10 09:47
    I do not believe it is possible to use the count function on two pins at
    once. Perhaps you could use external counters.

    Could you explain in more detail about the project?

    Ken

    ===========
    Is it possible to use a stamp as a counter on two inputs at the same
    time? I would like to subtract one counter from the other and not
    miss any counter pulses.


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-10 14:49
    Answer depends on: is there a guaranteed maximum pulse rate,
    guaranteed minimum pulse duration and if so what are they?

    Regards,

    Steve

    On 9 Jun 04 at 17:48, daytonacopue wrote:

    > Is it possible to use a stamp as a counter on two inputs at the same
    > time? I would like to subtract one counter from the other and not
    > miss any counter pulses.
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-10 14:55
    That depends on your input speed. If it's slow enough, you could write
    a code loop that would manually count the pulses on both pin. If your
    inputs are very fast, you could use something like the PWMPAL to handle
    the counting for you.

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


    Original Message
    From: daytonacopue [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=677Z3JsqfwykbgYtziOE82aCbcy_jCoWElCI34hLc5VWi7vjPzqu0v-Q2zta1pe0Ms5toEEwg0hTT4RtKQ]turbo_tex@h...[/url
    Sent: Wednesday, June 09, 2004 12:49 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Stamp counting capabilities


    Is it possible to use a stamp as a counter on two inputs at the same
    time? I would like to subtract one counter from the other and not
    miss any counter pulses.
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-10 19:26
    I want to build a simple fuel differentiator. On a Electronic Fuel
    Injection sytem. The fuel system has a send and return line. A
    transducer has to be placed into each line. The transducers will
    pulse 3300/liter or 7000 depending on application. The fuel pump will
    pump 110 to 140 liters per hr depending on pump. For 3300
    pulses/Liter usage 140 Liter/hr = 2.33 Liter/min = 7689 pulses/min =
    128 pulses/sec. For 7000 pulses/Liter usage 140 Liter/hr = 2.33
    Liter/min = 16310 pulses/min = 271 pulses/sec.

    The two transducer pulse counts will be subtracted to determine the
    pulse count of fuel used. I am reading about the Stamps and do not
    know their capabilities. I thought I might have to build counters but
    wanted to make sure.... I could use the counter to interupt the Stamp
    to read, subtract, clear the counters, and display to update. I also
    thought about sampling the pulses for frequency and calculate but it
    would not be as accurate. I need accuracy...

    --- In basicstamps@yahoogroups.com, smartdim@a... wrote:
    > I do not believe it is possible to use the count function on two
    pins at
    > once. Perhaps you could use external counters.
    >
    > Could you explain in more detail about the project?
    >
    > Ken
    >
    > ===========
    > Is it possible to use a stamp as a counter on two inputs at the
    same
    > time? I would like to subtract one counter from the other and not
    > miss any counter pulses.
    >
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-10 19:47
    Jon

    I left details of the project I want to build in the post reply to
    smartdim.

    I looked at the PWMPAL you suggested. It looks like the ticket. Will
    the PWMPAL interface to the Basic Stamp 2 OEM Module?

    --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
    wrote:
    > That depends on your input speed. If it's slow enough, you could
    write
    > a code loop that would manually count the pulses on both pin. If
    your
    > inputs are very fast, you could use something like the PWMPAL to
    handle
    > the counting for you.
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Dallas Office
    >
    >
    >
    Original Message
    > From: daytonacopue [noparse][[/noparse]mailto:turbo_tex@h...]
    > Sent: Wednesday, June 09, 2004 12:49 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Stamp counting capabilities
    >
    >
    > Is it possible to use a stamp as a counter on two inputs at the
    same
    > time? I would like to subtract one counter from the other and not
    > miss any counter pulses.
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-11 04:44
    Sure, you'll just have to put it into a 24-pin socket.

    Jon Williams


    Original Message
    From: daytonacopue [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=jdlHbXyG0uIw4Ok2gBr2vTULTtl4gh9jSdt_LLGCFCbMi7GEdbADWpbzQOYYWkRzC13JrlmsCCjGhTM]turbo_tex@h...[/url
    Sent: Thursday, June 10, 2004 1:48 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Re: Stamp counting capabilities


    Jon

    I left details of the project I want to build in the post reply to
    smartdim.

    I looked at the PWMPAL you suggested. It looks like the ticket. Will
    the PWMPAL interface to the Basic Stamp 2 OEM Module?

    --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
    wrote:
    > That depends on your input speed. If it's slow enough, you could
    write
    > a code loop that would manually count the pulses on both pin. If
    your
    > inputs are very fast, you could use something like the PWMPAL to
    handle
    > the counting for you.
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Dallas Office
    >
    >
    >
    Original Message
    > From: daytonacopue [noparse][[/noparse]mailto:turbo_tex@h...]
    > Sent: Wednesday, June 09, 2004 12:49 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Stamp counting capabilities
    >
    >
    > Is it possible to use a stamp as a counter on two inputs at the
    same
    > time? I would like to subtract one counter from the other and not
    > miss any counter pulses.




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