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Parallax or maybe AWC Question — Parallax Forums

Parallax or maybe AWC Question

ArchiverArchiver Posts: 46,084
edited 2004-03-15 23:53 in General Discussion
I Ran into a really strange problem. I'm using a Stamp SX to read
two computer mouse units with the AWC PAK IX chips for robot
navigation. The first uses P5, P6, and P7 for Transmit, Receive and
Enable respectively. The second uses P8, P9, and P10 also Transmit,
Receive and Enable respectively. I initialized the first and then the
second with the exact same codes, then do a read on the first chip,
then the weird thing happens, the program locks up on a read of the
second chip.
During trouble shooting, I determined I can run either chip alone
with no problem at all, but the combination of both is a problem.
The solution I found in swapping the serin commands I execute to
read the chips. Everything else is as I originally wrote the program.
I just read the second chip first and the first chip second and it
works perfectly. I don't really have a problem now with this solution
in place, but I would like to know if there is some rule I've violated
that prevented me from reading from "higher" numbered pins after
reading lower numbered pins. It cost me a couple of hours head
scratching and rechecking connections that I could have used in other
activities not to mention a few extra gray hairs.
I'm happily continuing my project but...

Any ideas?

Steve Alaniz

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-03-15 22:00
    Hi Steve,

    That's a new one on me. I think you mean PAK XI though (the PAK-IX is an
    A/D, floating point unit). I can't help but wonder if you fixed some bad
    connection or faulty breadboard issue while moving stuff around? Without
    changing anything else, if you simply reverse the order of the SERINs now
    will it still fail?

    I would guess it was some connection not being made or a short between two
    connections somewhere. Very strange.

    Regards,

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




    Original Message
    From: catgirldo [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Uet-5b1inZJltcsp2Eux8X1OiEORGcsUM-4OxhqGnP8JeA0kCnEu1CDccmIafXxy2VwM1K_w3WJKzBWUobU]catgirldo@y...[/url
    Sent: Monday, March 15, 2004 3:52 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Parallax or maybe AWC Question


    I Ran into a really strange problem. I'm using a Stamp SX to read two
    computer mouse units with the AWC PAK IX chips for robot navigation. The
    first uses P5, P6, and P7 for Transmit, Receive and Enable respectively. The
    second uses P8, P9, and P10 also Transmit, Receive and Enable respectively.
    I initialized the first and then the second with the exact same codes, then
    do a read on the first chip, then the weird thing happens, the program locks
    up on a read of the second chip.
    During trouble shooting, I determined I can run either chip alone with no
    problem at all, but the combination of both is a problem.
    The solution I found in swapping the serin commands I execute to read the
    chips. Everything else is as I originally wrote the program. I just read the
    second chip first and the first chip second and it works perfectly. I don't
    really have a problem now with this solution in place, but I would like to
    know if there is some rule I've violated that prevented me from reading from
    "higher" numbered pins after reading lower numbered pins. It cost me a
    couple of hours head scratching and rechecking connections that I could have
    used in other activities not to mention a few extra gray hairs.
    I'm happily continuing my project but...

    Any ideas?

    Steve Alaniz






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  • ArchiverArchiver Posts: 46,084
    edited 2004-03-15 23:53
    OOPS! Sorry Al, PAK-XI.
    I've tried to verify the failure and naturally it works both ways
    now. I had ruled out a hardware failure by using a scope to trace the
    signals and verify their presence. That's when I started the software
    tracing. I can only speculate that I may have a bad socket, but it
    eludes me for the moment.
    Well good call Al... guess my hardwired problems are between the
    eyes this time. Thanks for the reply!


    Steve


    --- In basicstamps@yahoogroups.com, "Al Williams" <alw@a...> wrote:
    > Hi Steve,
    >
    > That's a new one on me. I think you mean PAK XI though (the PAK-IX is an
    > A/D, floating point unit). I can't help but wonder if you fixed some bad
    > connection or faulty breadboard issue while moving stuff around? Without
    > changing anything else, if you simply reverse the order of the
    SERINs now
    > will it still fail?
    >
    > I would guess it was some connection not being made or a short
    between two
    > connections somewhere. Very strange.
    >
    > Regards,
    >
    > Al Williams
    > AWC
    > * New Kits: http://www.awce.com/kits.htm
    >
    >
    >
    >
    >
    Original Message
    > From: catgirldo [noparse][[/noparse]mailto:catgirldo@y...]
    > Sent: Monday, March 15, 2004 3:52 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Parallax or maybe AWC Question
    >
    >
    > I Ran into a really strange problem. I'm using a Stamp SX to read two
    > computer mouse units with the AWC PAK IX chips for robot navigation. The
    > first uses P5, P6, and P7 for Transmit, Receive and Enable
    respectively. The
    > second uses P8, P9, and P10 also Transmit, Receive and Enable
    respectively.
    > I initialized the first and then the second with the exact same
    codes, then
    > do a read on the first chip, then the weird thing happens, the
    program locks
    > up on a read of the second chip.
    > During trouble shooting, I determined I can run either chip alone
    with no
    > problem at all, but the combination of both is a problem.
    > The solution I found in swapping the serin commands I execute to
    read the
    > chips. Everything else is as I originally wrote the program. I just
    read the
    > second chip first and the first chip second and it works perfectly.
    I don't
    > really have a problem now with this solution in place, but I would
    like to
    > know if there is some rule I've violated that prevented me from
    reading from
    > "higher" numbered pins after reading lower numbered pins. It cost me a
    > couple of hours head scratching and rechecking connections that I
    could have
    > used in other activities not to mention a few extra gray hairs.
    > I'm happily continuing my project but...
    >
    > Any ideas?
    >
    > Steve Alaniz
    >
    >
    >
    >
    >
    >
    > 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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