AVR-Chat

At 01:43 PM 10/29/04 -0500, you wrote:

>I would like to transfer data some distance (100 feet in one case, 400 feet in
>another) between AVRs and I'm looking for the least complex, least 
>expensive way
>to accomplish this.  Environment:
>
>1) Using facilities available on AVR processors (such as UART, TWI, etc.)
>
>2) I have cable in the ground which is Telco grade, gel filled, direct bury
>cable with 6 twisted pair
>
>3) Speed is not critical.  Of course I'd like to go as fast as possible 
>but I'm
>willing to sacrifice speed to keep complexity/cost down ... Well, I'd 
>rather not
>go back to the 110 bps days!  :-)
>
>4) Multimaster is desirable

RS-485?  Differential, multimaster possible , uses UART, drivers are 
relatively inexpensive and readily available, sounds like a good 
fit.  TWI/IIC is really meant for board scale distances although I 
understand people have driven it further.  There are several RS-485 SW 
protocols available and it's not hard to build your own.

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,
be they legal, genetic, or physical.  If you don't believe me, try to
chew a radio signal. "

                         Kelvin Throop, III