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Basic Stamp for RS232 baud rate convertor and buffer? — Parallax Forums

Basic Stamp for RS232 baud rate convertor and buffer?

ArchiverArchiver Posts: 46,084
edited 2001-01-24 15:13 in General Discussion
I am not sure whether or not a Stamp is the answer to my problem!· Maybe someone can put me straight?

I have a requirement to connect two pieces of equipment (a test instrument and a fixed baud rate radio modem) via a RS232 connection.· The problem is that the instrument can only communicate at 9600 baud and does not use the control lines (DSR, DTR, RTS and CTS).· The modem can only·communicate at a maximum of 4800 baud, but can accept data at 9600 baud!· The modem only has a 1KB buffer, and thus buffer over-runs occur most of the time.

I need a small unit that will connect to the instrument at 9600, accept incoming data, buffer it (at least 8Kbyte), and play it out at 9600 or 4800, but taking cognisance of the RTS/CTS control lines.

Is this easy and feasable to implement with a Stamp or similar?

Here's hoping - thanks,

Derek Bristow

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2001-01-24 14:04
    Hi Derek,

    You'll have trouble buffering 8Kbytes with a Stamp.That's just not what it
    is meant to do.

    You can probably buy something like this off the shelf at www.blackbox.com.
    Also I used to work for a company that made something similar many years
    ago, but I don't know if they still do. Back then we didn't have a Web site,
    but I've heard they are now at www.baytechdcd.com -- their products always
    have multiple ports, but they also usually have buffers.

    Not 8K, but if you check out the SX University program at www.sxtech.com
    you'll find the design for an SSIB which is a SX-based serial buffer for the
    Stamp (that is, it works with the Stamp, not that it uses a Stamp). The SSIB
    could change baud rates, but it sure doesn't have an 8K buffer.

    Good luck!

    Al Williams
    AWC
    * HURRY: January sale is almost over -- see http://www.al-williams.com/awce
    for details

    Original Message
    From: Derek Bristow [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=JL4FBuFqkGTVieMU-bRxoc-zqy13_w5f2IYIVnEdJNVus1zIe8F0d_ejsj8-fs_zf3M2vMbUoR94EwnqfA]derek@i...[/url
    Sent: Wednesday, January 24, 2001 1:16 AM
    To: basicstamps@egroups.com
    Subject: [noparse][[/noparse]basicstamps] Fw: Basic Stamp for RS232 baud rate convertor and
    buffer?



    I am not sure whether or not a Stamp is the answer to my problem! Maybe
    someone can put me straight?

    I have a requirement to connect two pieces of equipment (a test instrument
    and a fixed baud rate radio modem) via a RS232 connection. The problem is
    that the instrument can only communicate at 9600 baud and does not use the
    control lines (DSR, DTR, RTS and CTS). The modem can only communicate at a
    maximum of 4800 baud, but can accept data at 9600 baud! The modem only has
    a 1KB buffer, and thus buffer over-runs occur most of the time.

    I need a small unit that will connect to the instrument at 9600, accept
    incoming data, buffer it (at least 8Kbyte), and play it out at 9600 or 4800,
    but taking cognisance of the RTS/CTS control lines.

    Is this easy and feasable to implement with a Stamp or similar?

    Here's hoping - thanks,

    Derek Bristow
  • ArchiverArchiver Posts: 46,084
    edited 2001-01-24 14:46
    I'd try the Rabbit 2000.· Although you have to program it in C, they have plenty of examples you can cut and paste from.

    www.rabbitsemiconductor.com/
    Mark

    I am not sure whether or not a Stamp is the answer to my problem!· Maybe someone can put me straight?

    I have a requirement to connect two pieces of equipment (a test instrument and a fixed baud rate radio modem) via a RS232 connection.· The problem is that the instrument can only communicate at 9600 baud and does not use the control lines (DSR, DTR, RTS and CTS).· The modem can only·communicate at a maximum of 4800 baud, but can accept data at 9600 baud!· The modem only has a 1KB buffer, and thus buffer over-runs occur most of the time.

    I need a small unit that will connect to the instrument at 9600, accept incoming data, buffer it (at least 8Kbyte), and play it out at 9600 or 4800, but taking cognisance of the RTS/CTS control lines.

    Is this easy and feasable to implement with a Stamp or similar?

    Here's hoping - thanks,

    Derek Bristow
  • ArchiverArchiver Posts: 46,084
    edited 2001-01-24 15:13
    I'd call the tech support No. for the Rabbit first. When I did, they talked me out of buying their own kit....
    Original Message
    From: Mark Schmidt [noparse][[/noparse]mailto:mschmidt@gpsgis.com]
    Sent: Wednesday, January 24, 2001 9:47 AM
    To: basicstamps@egroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Basic Stamp for RS232 baud rate convertor and buffer?

    I'd try the Rabbit 2000.· Although you have to program it in C, they have plenty of examples you can cut and paste from.

    www.rabbitsemiconductor.com/
    Mark

    I am not sure whether or not a Stamp is the answer to my problem!· Maybe someone can put me straight?

    I have a requirement to connect two pieces of equipment (a test instrument and a fixed baud rate radio modem) via a RS232 connection.· The problem is that the instrument can only communicate at 9600 baud and does not use the control lines (DSR, DTR, RTS and CTS).· The modem can only·communicate at a maximum of 4800 baud, but can accept data at 9600 baud!· The modem only has a 1KB buffer, and thus buffer over-runs occur most of the time.

    I need a small unit that will connect to the instrument at 9600, accept incoming data, buffer it (at least 8Kbyte), and play it out at 9600 or 4800, but taking cognisance of the RTS/CTS control lines.

    Is this easy and feasable to implement with a Stamp or similar?

    Here's hoping - thanks,

    Derek Bristow
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