BS2SX - party line communications
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HELP!
· I need help getting a multi-stamp system, where each stamp communicates over a common line [noparse][[/noparse]using texas Instruments SN75176 transceivers]. I can capture data using low baud rate for transmitting stamp, and high baud rate for receiving stamp, but data is wrong, and not consistant.
George@csi-aero.com
· I need help getting a multi-stamp system, where each stamp communicates over a common line [noparse][[/noparse]using texas Instruments SN75176 transceivers]. I can capture data using low baud rate for transmitting stamp, and high baud rate for receiving stamp, but data is wrong, and not consistant.
George@csi-aero.com
Comments
>HELP!
>
> I need help getting a multi-stamp system, where each stamp communicates
over a common line [noparse][[/noparse]using texas Instruments SN75176 transceivers]. I can
capture data using low baud rate for transmitting stamp, and high baud rate
for receiving stamp, but data is wrong, and not consistant.
>George@c...
>
George -
This TI chip supports RS-485, this is not something the Stamp can deal with
directly. There are solutions, however. Your best bet is to obtain a copy of
Serial Port Complete, a book by Jan Axleson. Her website is [noparse][[/noparse] www.lvr.com ].
Although this book is not about Stamps is covers the entre of most serial
protocols. It also deals with interfacing to those protocals in various ways.
This presumes you want to learn about such things, and have the time to do the
necessary learning.
If you are familiar with the protocol, but unfamiliar with the Stamp, you
might
benefit from some of the examples found at www.hth.com/losa . LOSA is an
acronym
for List Of Stamp Applications. This is a compendium of various projects,
done by Stampers. It is a completely voluntary effort.
If you are in need of a "quick-fix" and in a hurry to bring a Stamp or
other device onto an RS-485 network, check B&B Electronics [noparse][[/noparse]
http://www.bb-elec.com/ ]. They have various protocal converters and other
serial device equipment. Bringing the RS-485 to RS-232 may begin to give
you what you need. Once you get to that point the protocal becomes easier
to deal with, but full function may be lost by the time you get to the
stamp end.
If you are electronically inclined, and wish to make your own converter,
refer to
the first reference. Jan's book will be your key.
Concerns about voltage level shifting are generally addressed by the
MAX-232 (Maxim: www.maximic.com) or other similar devices. I suspect TI may
have some too.
So there's a brief help summary regarding serial protocols and the Stamp.
If you
have specific needs or questions, please state them in detail.
Regards,
Bruce
>
>Attachment Converted: "d:\eudora\attach\basicst3.htm"
>
>At 02:39 PM 4/13/00 -0700, George promulgated:
>>HELP!
>>
>> I need help getting a multi-stamp system, where each stamp communicates
>over a common line [noparse][[/noparse]using texas Instruments SN75176 transceivers]. I can
>capture data using low baud rate for transmitting stamp, and high baud rate
>for receiving stamp, but data is wrong, and not consistant.
>>George@c...
>>
>
George -
Sorry - I just realized you had BS2-SX in the title. The Parallax website is
down at the moment, but if you would like, I can send you the pertinant data
regarding serail communication and the BS2-SX. The baudmode parameters differ
from those in the book.
Regards,
Bruce