On Fri, 2005-05-20 at 00:24 -0400, Matthew Miller wrote:
> Hi,
> 
> On Thu, May 19, 2005 at 02:26:31PM -0500, PicDude wrote:
> >
> > The issue though, is that I2C has a limited distance, though I understand that 
> > at lower speeds, I can get more distance.  But how much?  I have yet to learn 
> > the specifics of I2C, including the various speeds available, but at a high 
> > level, would a couple hundred feet reliably be possible for my snail-like 
> > data-rate?
> 
> I doubt that I2C will work at those distances. The main problems will be
> noise, and the capacitance of the lines (I don't have the I2C spec. handy so
> I can't tell you what the max capacitance is.) Don't expect I2C to work for
> more that a couple of meters. I have seen it work at upto three meters
> before.

I agree I2C may not be the best choice, but it's certainly not limited
to small distances.

My house monitoring network is I2C, and the farthest station is about 20
meters (60 feet). As long as you do things slow enough I2C is definitely
possible to get working.

That said, even going to a "multidrop" rs232 would be far better, with
rs485 and CAN being much preferred options. TTYL

-----------------------------
Herbert's PIC Stuff:
http://repatch.dyndns.org:8383/pic_stuff/

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