On Wednesday 13 September 2017 12:50:15 Nicklas Karlsson wrote: > > > No SPI over long cable. For long cable RS422 will work, there is a > > > tradeoff between cable length and speed. > > > > Poor wording on my part. I had, once the terminations are sorted, > > visions of a 3 to 4 foot cable, defined as a long SPI cable. > > > > Right now, terms are not well characterized on either end and it > > takes some loading trickery to make a 6 inch cable work. Bertho and > > I spent some time optimizing it to get 30.5 megabit one way, and 25 > > megabit the other direction. And its now working well to a Mesa > > 7i90 with a 1" cable. > > Ethernet shielded twisted pair four pairs like this: sck+gnd, > miso+gnd, mosi+gnd, chip select + gnd. Or flat cable with a gnd cable > between each of them. Or of course Ethernet if available.
No, the tcp is too slow, much latency. However, the above scheme, made into ready-made hardware and a matching rj45 socket signal assignment on those mesa cards that can support spi, like the 7i90, would sure go a long ways toward making such a lashup truly plug and play instead of the cast iron bitch it is now, all ready to drop onto the gpio pins of a pi-3b or a rock64. On the 7i90, if that isn't the signal vs pin setup now, I've no clue, so perhaps 2 of the rj45 adaptors would be needed, each custom wired. I'm playing what if of course, but it sure sounds good to me. Peter? Possible product if a design could be flea clipped to function as either end of the circuit with some cat6e in the middle. Even better, a new "7i91" whose rj45 is already configured that way. That, and a pci-e to spi card for a std pc if it can be made to run over a usable distance. Reasonable for me is 4 feet. I would love to be able to replace the 5i25's running my mills with a 7i90 + 3 ea 7i42ta's, maybe even converting TLM eventually. I am in hog heaven on the Sheldon with all the i/o the 7i90 gives me. I don't have coolant hooked up yet, but I still have about 35 open i/o's yet. Might rig one of them to control a coffee cup hot pad, my coffee gets cold when I get busy setting something up. 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
