7i90 questions

I rechecked the spi cable, seems as solid as it was initially. When launching lcnc, it will error out with different errors(I particularly like "ui90 board doesnt exist") . if i then unplug the power from the 7i84 and repower, it will load up. No halui and the stepper axis wont home. Anything that can be done to remedy this situation asap would be appreciated. I think we are hitting the limits of what the RSPI is capable of, at least at this point in time.

Really looks like SPI signal integrity troubles.
How long is the cable from the RSPI to the 7I90 and does is terminate all 8 ground leads on both ends?
(it should be a 26 pin flat cable with all 8 ground leads terminated at the RSPI, which requires tying multiple grounds together at the RSPI end)


Does the driver allow you to select the clock speed? If I make a filtered version of the firmware
it will need to use a slower clock

The spi cable is 3 inches long, it is a flat cable. Im using the four grounds from the rspi to four ground pins on the 7i90. It was working very well. I can ground the other four.

From the man page "The maximum SPI clock of the BCM2835-SPI driver and the 7i90 is documented over 32MHz."'

this is as much as i can find out.

I wonder if this is the same issue that Gene on the LinuxCNC maling list has where
the driver starts at 50 MHz (which is going to be very marginal)

this may be of some interest

www.raspberrypi.org/documentation/hardwa...errypi/spi/README.md

PCW,

It appears there is a bug somewhere either in the above bit file of the hm2 driver , im having endless goofy problems(see my other thread in Basic configuration) can you configure this bit file for two encoders? Thanks

1 encoder works fine, i just tested it
(there was a bug with a single encoders maybe 6 years ago but long since fixed)

Did you see Bertho Stultiens thread on the LinuxCNC users list? The hm2-rspi driver has serious bugs in SPI clock speed setting among other things. He has a patched version that's worth trying. One nice thing with his patches is that
he has added a way to set the SPI clock speed.

yes i have, Im working on getting the driver installed as I type. Thanks....

can you please make a bit file like the last one but with 2 encoders. This isnt working for my application. I am unable to home my linear stepper axis. Thanks.

I can make one sometime today, but does the encoder work (count properly) independent of any homing issues?
if so this is more likely a joint/axis/kinematics issue of some kind, unrelated to hardware