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Dual serial interfaces with Stamp? — Parallax Forums

Dual serial interfaces with Stamp?

ArchiverArchiver Posts: 46,084
edited 2003-02-06 15:27 in General Discussion
I'm a semi-newbie when it comes to interfacing the Stamp and have a
project I am trying to get off the ground.

I am trying to interface both a serial GPS and a Quadravox voice chip
with a BS2p24. Since both communicate via serial and there is only
one comm port on the stamp, what can I do? Do I need another Stamp?

If I can't make it work with one stamp, two might be possible, but
then, I'd have to link the two stamps separately with I/O pins (I
guess?!?).

Help me Obi Wan KenStampcommunity! You're my only hope! Just
kidding, but seriously, I'd really appreciate any advice from the
more experienced posters here. Thanks!

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-02-06 03:52
    Any I/O pin can be used for serial communications using the SERIN and SEROUT
    PBASIC commands and a transceiver chip like the MAX232 to adjust the signal
    levels. The "gotcha" is that it is fairly easy to overrun input on the
    basic stamp, but that's probably not an issue with this application. The
    stamp can definitely handle the GPS and I would anticipate that you will be
    mainly outputting to the Quadravox.

    If you haven't already seen it, the Parallax site has a very complete sample
    GPS application.

    -- Al Margolis, founder
    www.hobbyengineering.com
    The WEB's newest source for robotics supplies and information

    Original Message
    From: i1patrick <i1patrick@y...> [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=c7sGAK0Ph_7tC0uVimUx1TktmkjjRPCqZ_ZPaOmcixVAoovMn75-EcILIhG4pVVcohPUPmR_HFzz]i1patrick@y...[/url
    Sent: Wednesday, February 05, 2003 7:03 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Dual serial interfaces with Stamp?



    I'm a semi-newbie when it comes to interfacing the Stamp and have a
    project I am trying to get off the ground.

    I am trying to interface both a serial GPS and a Quadravox voice chip
    with a BS2p24. Since both communicate via serial and there is only
    one comm port on the stamp, what can I do? Do I need another Stamp?

    If I can't make it work with one stamp, two might be possible, but
    then, I'd have to link the two stamps separately with I/O pins (I
    guess?!?).

    Help me Obi Wan KenStampcommunity! You're my only hope! Just
    kidding, but seriously, I'd really appreciate any advice from the
    more experienced posters here. Thanks!




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  • ArchiverArchiver Posts: 46,084
    edited 2003-02-06 09:39
    Any Stamp pin can be a serial port -- look at the SERIN and SEROUT commands.
    Its just that the one port is set up for programming and debug use.

    Original Message

    > I'm a semi-newbie when it comes to interfacing the Stamp and have a
    > project I am trying to get off the ground.
    >
    > I am trying to interface both a serial GPS and a Quadravox voice chip
    > with a BS2p24. Since both communicate via serial and there is only
    > one comm port on the stamp, what can I do? Do I need another Stamp?
    >
    > If I can't make it work with one stamp, two might be possible, but
    > then, I'd have to link the two stamps separately with I/O pins (I
    > guess?!?).
  • ArchiverArchiver Posts: 46,084
    edited 2003-02-06 14:17
    Rodent,

    I am a few weeks ahead of you on the dual serial port thing.

    Using the max232 chips works well. Al Williams has a very nice
    connector and board interface with the max 232 to speed up the
    process greatly.

    http://www.al-williams.com/rs1.htm

    Thats the good news, I have found the tough part is the max speed the
    stamp can input directly. Depending on the commands I have found that
    2400 is marginal ans 1200 bps is reliable.

    9600 out of the stamp works well with the max232.

    The path I am presently going down is using the Max3100 or 3110 uart
    buffer. the limitation there is the buffer is only 8 byes deep. For
    me I need to test the max 3110 to see if I can dump the buffer fast
    enough to grab the next couple of 8 byte groups.

    Other great articles talking about the delay times between the ser in
    and out comands are:

    http://www.emesystems.com/BS2rs232.htm

    http://www.phanderson.com/stamp/tutorial_10.html

    If you get to the point of needing a max 3100/3110

    This is a great reference.

    http://www.wd5gnr.com/suart.htm

    Brent


    --- In basicstamps@yahoogroups.com, Rodent <daweasel@s...> wrote:
    > Any Stamp pin can be a serial port -- look at the SERIN and SEROUT
    commands.
    > Its just that the one port is set up for programming and debug use.
    >
    >
    Original Message
    >
    > > I'm a semi-newbie when it comes to interfacing the Stamp and have
    a
    > > project I am trying to get off the ground.
    > >
    > > I am trying to interface both a serial GPS and a Quadravox voice
    chip
    > > with a BS2p24. Since both communicate via serial and there is
    only
    > > one comm port on the stamp, what can I do? Do I need another
    Stamp?
    > >
    > > If I can't make it work with one stamp, two might be possible, but
    > > then, I'd have to link the two stamps separately with I/O pins (I
    > > guess?!?).
  • ArchiverArchiver Posts: 46,084
    edited 2003-02-06 14:44
    Sorry for coming in late on the thread. If you're working with GPS (or
    anything else with a long string of data), you may want to take advantage of
    the BS2p and BS2pe feature that allows a serial stream to be buffered into
    the scratchpad RAM. We've done a lot of experimenting with GPS and have
    information posted on our web site.

    The advantage is that you can capture the whole string and then parse it
    after, not having to use serial modifiers (SKIP) to grab data from your
    string. In my GPS program for the BS2p, here's the line that captures the
    GPS input:

    SERIN GPSpin, N4800, 3000, No_GPS_Data, [noparse][[/noparse]WAIT("GPRMC,"), SPSTR 65]

    This line will capture 65 bytes of GPS data after the GPRMC header. Once
    it's in the scratchpad RAM, it's easier to parse out. Code that we've posted
    has routines for parsing data that is in a specific location and there is a
    routine that will parse from a specific field in the data (it counts commas
    to find the field).

    -- Jon Williams
    -- Parallax


    In a message dated 2/6/2003 8:18:24 AM Central Standard Time,
    broyles@i... writes:

    > Rodent,
    >
    > I am a few weeks ahead of you on the dual serial port thing.
    >
    > Using the max232 chips works well. Al Williams has a very nice
    > connector and board interface with the max 232 to speed up the
    > process greatly.
    >
    > http://www.al-williams.com/rs1.htm
    >
    > Thats the good news, I have found the tough part is the max speed the
    > stamp can input directly. Depending on the commands I have found that
    > 2400 is marginal ans 1200 bps is reliable.
    >
    > 9600 out of the stamp works well with the max232.
    >
    > The path I am presently going down is using the Max3100 or 3110 uart
    > buffer. the limitation there is the buffer is only 8 byes deep. For
    > me I need to test the max 3110 to see if I can dump the buffer fast
    > enough to grab the next couple of 8 byte groups.
    >
    > Other great articles talking about the delay times between the ser in
    > and out comands are:
    >
    > http://www.emesystems.com/BS2rs232.htm
    >
    > http://www.phanderson.com/stamp/tutorial_10.html
    >
    > If you get to the point of needing a max 3100/3110
    >
    > This is a great reference.
    >
    > http://www.wd5gnr.com/suart.htm
    >
    > Brent
    >
    >
    > --- In basicstamps@yahoogroups.com, Rodent <daweasel@s...> wrote:
    > >Any Stamp pin can be a serial port -- look at the SERIN and SEROUT
    > commands.
    > >Its just that the one port is set up for programming and debug use.
    > >
    > >
    Original Message
    > >
    > >>I'm a semi-newbie when it comes to interfacing the Stamp and have
    > a
    > >>project I am trying to get off the ground.
    > >>
    > >>I am trying to interface both a serial GPS and a Quadravox voice
    > chip
    > >>with a BS2p24. Since both communicate via serial and there is
    > only
    > >>one comm port on the stamp, what can I do? Do I need another
    > Stamp?
    > >>
    > >>If I can't make it work with one stamp, two might be possible, but
    > >>then, I'd have to link the two stamps separately with I/O pins (I
    > >>guess?!?).
    >



    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-02-06 15:27
    Umm, you sure you replied to the right person?

    **********

    To be conscious that you are ignorant is a great step to knowledge.

    -- Benjamin Disraeli


    Original Message

    > Rodent,
    >
    > I am a few weeks ahead of you on the dual serial port thing.
    >
    > Using the max232 chips works well. Al Williams has a very nice
    > connector and board interface with the max 232 to speed up the
    > process greatly.
    >
    > http://www.al-williams.com/rs1.htm
    >
    > Thats the good news, I have found the tough part is the max speed the
    > stamp can input directly. Depending on the commands I have found that
    > 2400 is marginal ans 1200 bps is reliable.
    >
    > 9600 out of the stamp works well with the max232.
    >
    > The path I am presently going down is using the Max3100 or 3110 uart
    > buffer. the limitation there is the buffer is only 8 byes deep. For
    > me I need to test the max 3110 to see if I can dump the buffer fast
    > enough to grab the next couple of 8 byte groups.
    >
    > Other great articles talking about the delay times between the ser in
    > and out comands are:
    >
    > http://www.emesystems.com/BS2rs232.htm
    >
    > http://www.phanderson.com/stamp/tutorial_10.html
    >
    > If you get to the point of needing a max 3100/3110
    >
    > This is a great reference.
    >
    > http://www.wd5gnr.com/suart.htm
    >
    > Brent
    >
    >
    > --- In basicstamps@yahoogroups.com, Rodent <daweasel@s...> wrote:
    > > Any Stamp pin can be a serial port -- look at the SERIN and SEROUT
    > commands.
    > > Its just that the one port is set up for programming and debug use.
    > >
    > >
    Original Message
    > >
    > > > I'm a semi-newbie when it comes to interfacing the Stamp and have
    > a
    > > > project I am trying to get off the ground.
    > > >
    > > > I am trying to interface both a serial GPS and a Quadravox voice
    > chip
    > > > with a BS2p24. Since both communicate via serial and there is
    > only
    > > > one comm port on the stamp, what can I do? Do I need another
    > Stamp?
    > > >
    > > > If I can't make it work with one stamp, two might be possible, but
    > > > then, I'd have to link the two stamps separately with I/O pins (I
    > > > guess?!?).
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