AVR-Chat

Thanks for everyone's input.   It's always good to get confirmation!   I'll
use one pair for SDA+GND and another for SCL+GND.  Or I may substitute V+
for one GND.

 

I have other reasons for wanting to use Cat5:  shielding, quick & easy
connect/disconnect, relatively cheap and easy to make up cables, and for my
situation cables that are flexible and easy to run convoluted paths is very
important.   I also have other uses for the remaining conductors in "RJ45"
cable, so that, plus shielding, is the reason I'm not just using "RJ11" or
"RJ12" modular cable (I've never been able to find such cable that is
shielded).

 

Steve

 

From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
Of Tim Gilbert
Sent: Tuesday, March 31, 2009 8:08 AM
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] i2c and twisted pair

 

You are correct that twisted pair will only help if you're running a
differential signal. In fact, running SDA and SCL on the same pair could, in
theory, make the signal worse.

Why bother with Cat5? I'd probably use a ribbon cable. You can tie every
other conductor to ground if it makes you feel better (the electrons won't
know either way). I'd just hook it up and try it. 

Regards,






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