On Wednesday 27 March 2019 08:12:48 TJoseph Powderly wrote: > ( list apology, I seem to have replied to posters rather than to the > list, and several times :-( > > re SPI comms Linuxcnc SBC microcontrollers ... > > it has been said on this mail list, > that SPI is a good candidate for a bus technology to work _with_ > realtime. > > heres some work in that vein (maybe overlooked) > > yeltrow's work: > a generic spi hal module so you can use other SPI devices ( rpi, > arduino, mcp23s17, ENC28J60, theres a lot of spi stuff to hang onto > such a bus ) > https://www.forum.linuxcnc.org/24-hal-components/28851-spi-bus-generic >-driver-and-st-l6480 > Interesting driver for the big stuffs. However, I wonder if yeltrow is aware of rpspi.ko, now part of LCNC. Not parport based but gpio, written specificly for the rpi3b. And I'm using it, writing to a Mesa 7i90 at 42 megabaud, and reading back from the 7i90 at 25 megabaud useing only 4 gpio pins for 2 or 3 target devices.
Perusal of that code might be of help to yeltrow. gpio seems to be about 10x faster than trying to simulate SPI over a parport. The 7i90 has both modes depending on the firmware loaded. > the files are on the forum for members linuxcnc-upload-2015-12-03.tar So this work handily predates rpspi.ko. Still, theres obviously things to be learned from the rpi version. > erste's work: > for ethernet circumventing usb ( via spi > interesting as spi and ethernet seem to be future avenues > http://erste.de/ethraw/README > > theres other efforts but less coupled to the spi grail > > tomp > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users 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> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
