On Monday 15 May 2017 03:12:34 andy pugh wrote: > On 15 May 2017 at 07:26, Gene Heskett <ghesk...@shentel.net> wrote: > > Or is this driver simply not a compatible driver for use on a pi 3b? > > Have you read the manpage? > http://linuxcnc.org/docs/2.7/html/man/man9/hm2_spi.9.html > > Do you have that spidev path? > Not visible in /dev now, but I had restored the driver string to rpspi, and now its reading 4 bytes of 0x00 for the name cookie. The spi driver apparently left it in a state that may take a full power down to restore.
> The manpage says that it works with the Odroid U3, with a specially > patched kernel. > I suspect that with an RPi you would expect rpispi to work better. It does work, when it works. And it may start working at any time, and work for a week. The quit again for no reason. The adapter board we can buy from OSHPark, has never worked. Perhaps I've assembled it wrong, the 40 pin header is on the bottom, pin 1 to pin 1, the resistors are 86.7 ohms, and the 26 pin socket is on top of the board. With pin one in the pin 1 hole. The pin 1 arrangement means the cable, if using that adaptor, has to come off the top of the pi board, bend back down and dive under the pi to get to the 7i90 unless one of them is upside down. So the pi is on standups about 30mm tall, which allows the cable to plug into the 7i90. pin 1 to pin 1. My home made cable comes across the top of the pi, then goes across the top of the 7i90, doing a 90 degree fold with the last inch, then hooks over the socket on the 7i90. It works and then doesn't. Changing the 7i90 makes no difference. I did change the pi out Saturday when I found the same sd card plugged into a different pi would boot. I've since built up an install based on the 04/17/2017 raspian jessie iso, used apt to update it, then overwrote its kernel with a 4.4.9-rt17 kernel. It boots in half the time, and the keyboard is much better behaved. But it still doesn't talk to a 7i90, giving the exact same error I've now posted 2 dozen times when my home made cable is used, or when the OSHPark adapter is in place it gets 00000000 00000000 00000000 000000000 back from the 7i90. My cobbled up cable connects all the pi's grounded pins thru to the 7i90, and the 4 signal pins but nothing else. I've rung the OSHPark pcb, and it seems to match that same connection setup, but has never worked with an even shorter piece of the 26 pin cable. I've connectors, and a roll of ribbon cable, so today I'm going to make another 26 pin jumper about 3" longer AND stick up some teeny loops of wire so I can get a scope probe onto the OSHPark pcb to see the signals on my gigahertz sampler scope. And this is without any noise injecting connections to the machine, no outputs on the 7i90 are connected. If I can make them talk, it will still take me 3 or 4 days to trace out each wire and reconnect it. And those 50 pin headers are such a pain in the ass I'm now waiting for Peter to get some 7i42TA's back in stock so I can order at least 2 of them so I've solid, screwed terminations to all the hookups, AND surge/static electricity protections on every I/O of the 7i90. What I have been building on perfboard works, but thats about 15 minutes a wire, and ugly as sin. Putting a scope probe on my homemade cable has to be done after its working because even a 10x probe messes with the signal enough for it to make com mistakes and it will not init itself when its probed. And it would be very helpfull if the spi signals were better described. I haven't a clue which one is going which direction from the descriptions I've been able to find. Would a set of 100x probes be a good buy? MPJA did have them. But not now. 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
