Apparantly the ran it at fairly high clockspeed.

The appnote AN444 talks about 300m at 100kbps, AN452 up to some 1800m with
reduced speed.
Both Appnotes is from Philips

AN444: Using the P82B715 I2C extender on long cables.
AN452: One mile long I2C communication using the P82B715.

With best regards

Tomas Larsson
Sweden
http://www.tlec.se
http://www.ebaman.com

Verus Amicus Est Tamquam Alter Idem 

> -----Original Message-----
> From: piclist-bounces@mit.edu 
> [mailto:piclist-bounces@mit.edu] On Behalf Of Dario Greggio
> Sent: Thursday, July 26, 2007 11:28 PM
> To: Microcontroller discussion list - Public.
> Subject: Re: [PIC]long distance I2C
> 
> Tomas Larsson wrote:
> 
> > Philips has some great application notes regarding long 
> distance com 
> > with I2C.
> > Somewhere I've seen a app note where the distance was 1000m 
> or more, 
> > cnat find it now though
> 
> In theory, slowing speed down to some 1KHz or even less, 
> should do the job... if you can afford it!
> 
> --
> Ciao, Dario
> --
> http://www.piclist.com PIC/SX FAQ & list archive View/change 
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