On Thu, 19 Mar 2020, Gene Heskett wrote:
Date: Thu, 19 Mar 2020 21:55:55 -0400
From: Gene Heskett <[email protected]>
Reply-To: "Enhanced Machine Controller (EMC)"
<[email protected]>
To: [email protected]
Subject: Re: [Emc-users] A hal question?
On Thursday 19 March 2020 19:12:37 Jon Elson wrote:
On 03/19/2020 04:02 PM, Gene Heskett wrote:
Greetings; I am trying to reduce the f/r error in an ATS667 based
encoder.
The index pulse is turned upside down by a reversal of spindel
direction. Tts the nature of the beast to remain in this stable
state until the approach of the triggering ferrous metal causes the
first reversal which the edge ignores, and then goes back true or
false as the ferrous piece crosses the center.
Does anyone see any problems with that?
The index pulse is only used during the initial synch to the
spindle, then the encoder is counted
up and down during reversals, without looking at the index
again. So, rigid tapping doesn't care
that the index signal from the encoder does something
different when the spindle is running in
reverse. It has been this way since I did the first ATS667
encoder hack some years ago.
Jon
Thats good news, but it looks as If I'll have to burn a new card to get
the pin Peter just told me about, unless mesaflash has grown the ability
to work thru an rpspi interface. I did have a machine with all the card
firmware on it but had to put it on the G0704 with a new SSD drive after
I apparently blew a pci bus driver during a local t-storm. The parport
on that box isn't currently in use so I'll have to see if that machine
can program a new 7i90HD since I don't believe the pi4 can w/o building
a hardware parport for it.
Mesaflash works over SPI on RPI3 and RPI4 (and probably many other SBCs)
because it uses the kernel SPI driver, not direct hardware access.
Note that running an older hm2_rpspi driver disables the kernel SPI driver
so you may have to reboot to run mesaflash if you have run LinuxCNC
(this has been fixed in master a few months ago)
sudo mesaflash --device 7i90 --interface spi --addr [spi device name] --readhmid
(I forget what the first RPI SPI device is named, maybe /dev/spi0.0?)
Thanks Jon, and stay safe.
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)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>
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Mesa Electronics
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