In the video I posted earlier (it's a year old)... the guy using that
chip says it cost him $40, he showed it on line for about $28.
(and that's just for the LS7366R by itself.)
https://www.youtube.com/watch?v=RLCPKa9SoF0
On 5/25/20 2:31 AM, Gene Heskett wrote:
On Monday 25 May 2020 03:35:05 John Dammeyer wrote:
BTW, Check out
https://lsicsi.com/datasheets/LS7366R.pdf
Is cute, but the only thing it can do better than a mesa 7i90, is work at
5 volts. Both are s32 counters, but the mesa needs >3.3 volt
protections. What is its per unit cost?
And its the protections that run the price of a complete 7i90 solution
out of sight. But you also get a total of 72 i/o lines so you generally
can do a complete system for a multiaxis machine on just one of them.
This device is interfaced via SPI and has a 32 bit quadrature counter
module. If you go in the direction of Raspberry Pi with LinuxCNC a
device like this can provide the spindle information. So if someone
was thinking of building a CNC cape for a Pi a device like this would
be a good idea. There are also devices from the same manufacturer
that can change quadrature into up/down pulses streams to use regular
counters inside the Pi.
But quadrature has one huge advantage over regular counters, you get both
speed AND direction from every edge that goes by.
John
-----Original Message-----
From: R C [mailto:cjv...@gmail.com]
Sent: May-24-20 6:01 PM
To: linuxcnc-users-list
Subject: Re: [Emc-users] Encoder HAL programming.
On 5/24/20 6:29 PM, andy pugh wrote:
On Mon, 25 May 2020 at 00:17, R C <cjv...@gmail.com> wrote:
I have been following this thread. I wrote some code that runs
on an RPI that can read a quadrature encoder, I have a few of
them, with different resolutions.
Is this something different to the normal LinuxCNC software
encoder that reads GPIO?
Is there some dedicated encoder counter hardware on the Pi?
Oh I am not running linux cnc on an rpi, I run it on a server
"class" machine.�� I was just curious about how these encoders work,
and why they didn't
work that well with my linux-cnc setup using a db25 BOB with the 2
benchtops I have.
So I decided to use an RPI (because it is easy to use GPIO pins to
read signals) and write some code to read these� encoder signals.
So I guess my answer is yes,� it is different from, what linux-cnc
running on a pi does (I would be surprised if it was similar)
I setup an RPI, hooked up a 2 line LCD display to it to display
rpms, wrote some interrupt driven code that reads the encoder and
displays it on the LCD. The idea is, I want
to try and see if I can read the encoder and then send signals back
to linux-cnc that it 'could handle".
So I have a 60ppr encoder,� 60 has a lot of dividers.� 2, 3, 4, 5,
6, 10, and 12� So if I can "transfer" a pulse with a consistent
delay exactly when the actual n-th pulse
comes in, I could turn a 60ppr� encoder into a 30, 20, 15, 12, 10, 6
or 5 ppr encoder by just skipping pulses,� while raising some GPIO
pins, that I connect to the BOB, when
I read a different set of GPIO pins directly from the encoder.
But as I said earlier,� I don't know a lot about the linux-cnc's
internals, and HAL, but it is something I am playing with to see if
it could work.
Ron
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
Cheers, Gene Heskett
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
