AVR-Chat

RS-485?  It should go that far and still have decent
bandwidth.  Drivers are relatively inexpensive as
well.

Have you a network picked out?  I've been looking at
HTH's S.N.A.P. (www.hth.com).

HTH,

Jeff Engel
--- Chuck Hackett <egroupscdh@WhiteTrout.net> 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
> 
> I'm thinking that the solution will use some king of
> differential driver.
> 
> I was doing some reading about TWI but it's unclear
> to me if this works in this
> situation.  The only thing I could find about
> distance limits was that the bus
> capacitance must be below 400pf but I don't know the
> capacitance of my cable ...
> 
> BTW:  I think this forum is appropriate for this, if
> not, please let me know.
> 
> Suggestions?
> 
> Cheers,
> 
> Chuck Hackett
> "Good judgment comes from experience, experience
> comes from bad judgment"
> 7.5" gauge Union Pacific Northern (4-8-4) 844
> http://www.whitetrout.net/Chuck


=====
Happiness is - positive intake manifold pressure.


		
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