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Baud rate question. — Parallax Forums

Baud rate question.

ArchiverArchiver Posts: 46,084
edited 2003-09-27 23:30 in General Discussion
I am new to BS2's and got my first one a few weeks ago and have made a
lot of progress making this cool BS2 do what I need.
( Spit out a hex string when I hit a button ).

Anyway, in theory it is working but I ran into a snag. I had some bad
information from the company that makes the gear I am interfacing this
to.

It just wouldn't work. I have the BS2 set at 38.4K, 8, N, 1. It works
wonderful with emulation software on a laptop. But when I hook it to
the actual
box it doesn't work. Problem is I need 38.4K, 8, E, 1. ( The emulation
software lets you change all these parameters, the actual HARDWARE
doesn't!!

Reading the dox today said you can do 8, N, 1 or 7, E, 1.

Does anyone know how ( or IF ) I can get these hex strings spit out on
a serial port at 8, E, 1???

Thanks

Alan

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-09-27 03:51
    I asked this a few days ago and I * REALLY * need an answer from some of you
    pro's out
    there??? HELP???????????


    --- In basicstamps@yahoogroups.com, Alan N. <alann19@c...> wrote:
    > I am new to BS2's and got my first one a few weeks ago and have made a
    > lot of progress making this cool BS2 do what I need.
    > ( Spit out a hex string when I hit a button ).
    >
    > Anyway, in theory it is working but I ran into a snag. I had some bad
    > information from the company that makes the gear I am interfacing this
    > to.
    >
    > It just wouldn't work. I have the BS2 set at 38.4K, 8, N, 1. It works
    > wonderful with emulation software on a laptop. But when I hook it to
    > the actual
    > box it doesn't work. Problem is I need 38.4K, 8, E, 1. ( The emulation
    > software lets you change all these parameters, the actual HARDWARE
    > doesn't!!
    >
    > Reading the dox today said you can do 8, N, 1 or 7, E, 1.
    >
    > Does anyone know how ( or IF ) I can get these hex strings spit out on
    > a serial port at 8, E, 1???
    >
    > Thanks
    >
    > Alan
  • ArchiverArchiver Posts: 46,084
    edited 2003-09-27 14:32
    The news is NOT GOOD.
    The stamp firmware allows 8 data no parity, and
    7 data even parity, and that's it.

    You might look at:
    http://www.rentron.com/Myke7.htm

    This site has an EXCELLENT tutorial of how to do
    232 "NRZ" signaling. Some options:

    1. Get a small PIC (16F629) and program the
    above routines into it, modified to support 8 data
    Even parity. Control the PIC with the BS2, and
    send the data out as "SHIFTOUT" on an SPI
    connection to the chip, which will then send
    the data out 8 data Even Parity.

    2. Get a 16C550 UART (1650, 16450) or
    compatible chip, and program it.
    You'll need to implement a parallel
    out port on the Stamp -- with 16 Stamp I/O pins,
    may not be a problem.

    3. Check out Black-Box for various protocol
    converters -- parallel to serial may let you
    set 8 data Even parity.

    --- In basicstamps@yahoogroups.com, "vintonalan" <alann19@c...> wrote:
    > I asked this a few days ago and I * REALLY * need an answer from
    some of you pro's out
    > there??? HELP???????????
    >
    >
    > --- In basicstamps@yahoogroups.com, Alan N. <alann19@c...> wrote:
    > > I am new to BS2's and got my first one a few weeks ago and have
    made a
    > > lot of progress making this cool BS2 do what I need.
    > > ( Spit out a hex string when I hit a button ).
    > >
    > > Anyway, in theory it is working but I ran into a snag. I had
    some bad
    > > information from the company that makes the gear I am interfacing
    this
    > > to.
    > >
    > > It just wouldn't work. I have the BS2 set at 38.4K, 8, N, 1. It
    works
    > > wonderful with emulation software on a laptop. But when I hook it
    to
    > > the actual
    > > box it doesn't work. Problem is I need 38.4K, 8, E, 1. ( The
    emulation
    > > software lets you change all these parameters, the actual
    HARDWARE
    > > doesn't!!
    > >
    > > Reading the dox today said you can do 8, N, 1 or 7, E, 1.
    > >
    > > Does anyone know how ( or IF ) I can get these hex strings spit
    out on
    > > a serial port at 8, E, 1???
    > >
    > > Thanks
    > >
    > > Alan
  • ArchiverArchiver Posts: 46,084
    edited 2003-09-27 17:59
    The Stamp cannot do 8,E,1, unaided. If you can use an external chip,
    a good choice is the MAX3100 (or others in that family of chips from
    http://www.maxim-ic.com). It is a UART that connects to the Stamp
    via an SPI buss. It has a lot of nice features, including the 8,E,1
    that you need. Stamp examples are available:
    <http://www.emesys.com/BS2IrDA.htm>
    <http://www.wd5gnr.com/suart.htm>
    <http://devices.sapp.org/micro/stamp2sx/max3110/>

    --regards,
    Tracy Allen
    http://www.emesystems.com




    >I asked this a few days ago and I * REALLY * need an answer from
    >some of you pro's out
    >there??? HELP???????????
    >
    >
    >--- In basicstamps@yahoogroups.com, Alan N. <alann19@c...> wrote:
    >> I am new to BS2's and got my first one a few weeks ago and have made a
    >> lot of progress making this cool BS2 do what I need.
    >> ( Spit out a hex string when I hit a button ).
    >>
    >> Anyway, in theory it is working but I ran into a snag. I had some bad
    >> information from the company that makes the gear I am interfacing this
    >> to.
    >>
    >> It just wouldn't work. I have the BS2 set at 38.4K, 8, N, 1. It works
    >> wonderful with emulation software on a laptop. But when I hook it to
    >> the actual
    >> box it doesn't work. Problem is I need 38.4K, 8, E, 1. ( The emulation
    >> software lets you change all these parameters, the actual HARDWARE
    >> doesn't!!
    >>
    >> Reading the dox today said you can do 8, N, 1 or 7, E, 1.
    >>
    >> Does anyone know how ( or IF ) I can get these hex strings spit out on
    >> a serial port at 8, E, 1???
    >>
    >> Thanks
    >>
    >> Alan
    >
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2003-09-27 23:30
    Alan-

    Here's a partial solution that may do you some good depending on what
    data you need to transmit.

    You can transmit any odd-parity byte in 8-bit, no-parity format and
    the receiver will view the data as 8-bit, even parity. The reason is
    the stop bit will be interpreted by the receiver as the parity bit,
    and this will form correct even parity over the data and "parity"
    bits. To add a little insurance, use SEROUT's delay parameter to
    extend the idle time between byte transmissions so there's plenty of
    time for the follow-on idle line to be interpreted as a stop bit.

    Regards,

    Steve
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