On Friday 16 May 2014 12:15:06 Marius Liebenberg did opine And Gene did reply: > Look under the High Speed Mode - up to 3.4Mb/sec > http://www.esacademy.com/en/library/technical-articles-and-documents/mi > scellaneous/i2c-bus.html > Thank you Marius. But nowhere in that link is any mention of using differential pair cabling, its all single ended all the way down. There may be chips that can convert it to cat5 differential pair's and back. I haven't researched it. Needing to tristate them when not busy complicates it.
However for your relatively short runs into or out of a BOB, a foot or so, it shouldn't be a problem. I was having visions of you sending data back from the torch head, maybe 15 feet with it. :( > On 2014-05-16 17:52, Gene Heskett wrote: > > On Friday 16 May 2014 11:23:52 Marius Liebenberg did opine > > > > And Gene did reply: > >> All the devices are situated on or near the bob or the controller > >> normally. I2c is not meant for long distance communications but > >> rather for closely located bussed devices. Having said that, I2c > >> over differential pair is very reliable over large distances. > > > > It must have grown the differential pair capability when I wasn't > > looking. The setup I fought with was single ended. > > You convert to diff pair and back yourself > > >> If the driver > >> software is implimented according to the interface specification it > >> will be reliable. > >> I am not intending nor will I advocate for it to be used for > >> communications but rather for hardware devices that will expand the > >> IO capability of Linuxcnc at reasonably low cost. > >> Some devices have an interface speed of over 2Mhz. I would say that > >> is pretty fast :) > > > > That also is much faster than the specs I looked up at the time. > > Getting the cable down to about 38.5 feet made it work, and my > > thoughts were that if it was going to be that pickity, I was no > > longer going to have an interest in it. > > > > URL to this new spec? > > > > Thanks Marius > > > > Cheers, Gene Heskett Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free." http://p.sf.net/sfu/SauceLabs _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
