Discussion:
about to give up on the pi's
(too old to reply)
Gene Heskett
2017-05-03 19:22:59 UTC
Permalink
Greetings;

What x86 board, suitably small but not that outpriced yudoo thingy, will
run linuxcnc well AND can do the spi thing?

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>
andy pugh
2017-05-03 21:11:02 UTC
Permalink
Post by Gene Heskett
What x86 board, suitably small but not that outpriced yudoo thingy, will
run linuxcnc well AND can do the spi thing?
I doubt that you will find an x86 PC with SPI. (though I could be wrong).

But the 7i90 can also do EPP.
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
Gene Heskett
2017-05-04 02:02:59 UTC
Permalink
Post by andy pugh
Post by Gene Heskett
What x86 board, suitably small but not that outpriced yudoo thingy,
will run linuxcnc well AND can do the spi thing?
I doubt that you will find an x86 PC with SPI. (though I could be wrong).
But the 7i90 can also do EPP.
Sure, but whats the bandwidth of a parport? 50 kilobaud equ maybe. When
the FCC with its radiated noise regulations got done about 20 years
back, I could not drive a parallel port printer with a coco3 as its
active time for both data and strobe was too short to get thru the
filters in the printer, and had to switch to a serial printer. A 1.79
MHz clock, active for half a cycle. Printers printed about every 3rd
character.

BUT, Got nother problem tonight, I can ping the buildbot, but cannot
connect with a package manager. Its rejecting http access. I don't have
a recommendation as to the proper size of brogan to reboot it with.
FWIW, it pings just fine, averaging 85 milliseconds from here in West
Virginia.

I have one card left that will boot it, so I believe I am going to dd
that puppy to a file on the usb hard drive thats plugged in and
recognized. And then reburn (and check for boot function) the other 4
cards so I'll have some backups. I don't believe the cards have failed,
but that the update that replaces almost everything in the /boot
partition has a bad file.

I see what was meant about x86 vs spi, a good comparison to dentist's
specializing in hens teeth, it seems all the x86 boards have the spi
rigged to handle only a bios update, and can do it on an otherwise DOA
board. Thats one hell of a screwup IMNSHO.

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>
Chris Albertson
2017-05-04 02:29:43 UTC
Permalink
According to the 7i90 user manual the RS422 interface is at least 2X faster
than the SPI interface. Mesa claims these speeds

Parallel Port ~1Mbit/sec
SPI 1~5 Mbit/Sec
RS422 10 Mbit/sec

If you use a standard Intel board you can buy a PCI card that does RS422
and send data at 10Mbits over a cat5 cable. You can also power the 7i90
using the same cable

You'd get the best bandwidth by using RS422 but the cost is higher because
you'd need the intel PC and the serial and graphic cards.

RS422 is balanced and opt isolated at the Mesa card end so you likely have
better noise resistance then with SPI.
Post by Gene Heskett
Post by andy pugh
Post by Gene Heskett
What x86 board, suitably small but not that outpriced yudoo thingy,
will run linuxcnc well AND can do the spi thing?
I doubt that you will find an x86 PC with SPI. (though I could be wrong).
But the 7i90 can also do EPP.
Sure, but whats the bandwidth of a parport? 50 kilobaud equ maybe. When
the FCC with its radiated noise regulations got done about 20 years
back, I could not drive a parallel port printer with a coco3 as its
active time for both data and strobe was too short to get thru the
filters in the printer, and had to switch to a serial printer. A 1.79
MHz clock, active for half a cycle. Printers printed about every 3rd
character.
BUT, Got nother problem tonight, I can ping the buildbot, but cannot
connect with a package manager. Its rejecting http access. I don't have
a recommendation as to the proper size of brogan to reboot it with.
FWIW, it pings just fine, averaging 85 milliseconds from here in West
Virginia.
I have one card left that will boot it, so I believe I am going to dd
that puppy to a file on the usb hard drive thats plugged in and
recognized. And then reburn (and check for boot function) the other 4
cards so I'll have some backups. I don't believe the cards have failed,
but that the update that replaces almost everything in the /boot
partition has a bad file.
I see what was meant about x86 vs spi, a good comparison to dentist's
specializing in hens teeth, it seems all the x86 boards have the spi
rigged to handle only a bios update, and can do it on an otherwise DOA
board. Thats one hell of a screwup IMNSHO.
Cheers, Gene Heskett
--
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
_______________________________________________
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--
Chris Albertson
Redondo Beach, California
Gene Heskett
2017-05-04 02:40:39 UTC
Permalink
Post by Chris Albertson
According to the 7i90 user manual the RS422 interface is at least 2X
faster than the SPI interface. Mesa claims these speeds
Parallel Port ~1Mbit/sec
SPI 1~5 Mbit/Sec
RS422 10 Mbit/sec
If you use a standard Intel board you can buy a PCI card that does
RS422 and send data at 10Mbits over a cat5 cable. You can also power
the 7i90 using the same cable
You'd get the best bandwidth by using RS422 but the cost is higher
because you'd need the intel PC and the serial and graphic cards.
RS422 is balanced and opt isolated at the Mesa card end so you likely
have better noise resistance then with SPI.
rs485 is the single ended cousin. Could a atom board keep up with that
with a pci-e rs422 card in it? That does have a bit of an attraction,
particularly from the noise safety dept. Silly Q: can the pi do rs422
over its gpio?
Post by Chris Albertson
Post by Gene Heskett
Post by andy pugh
Post by Gene Heskett
What x86 board, suitably small but not that outpriced yudoo
thingy, will run linuxcnc well AND can do the spi thing?
I doubt that you will find an x86 PC with SPI. (though I could be wrong).
But the 7i90 can also do EPP.
Sure, but whats the bandwidth of a parport? 50 kilobaud equ maybe.
When the FCC with its radiated noise regulations got done about 20
years back, I could not drive a parallel port printer with a coco3
as its active time for both data and strobe was too short to get
thru the filters in the printer, and had to switch to a serial
printer. A 1.79 MHz clock, active for half a cycle. Printers
printed about every 3rd character.
BUT, Got nother problem tonight, I can ping the buildbot, but cannot
connect with a package manager. Its rejecting http access. I don't
have a recommendation as to the proper size of brogan to reboot it
with. FWIW, it pings just fine, averaging 85 milliseconds from here
in West Virginia.
I have one card left that will boot it, so I believe I am going to
dd that puppy to a file on the usb hard drive thats plugged in and
recognized. And then reburn (and check for boot function) the other
4 cards so I'll have some backups. I don't believe the cards have
failed, but that the update that replaces almost everything in the
/boot partition has a bad file.
I see what was meant about x86 vs spi, a good comparison to
dentist's specializing in hens teeth, it seems all the x86 boards
have the spi rigged to handle only a bios update, and can do it on
an otherwise DOA board. Thats one hell of a screwup IMNSHO.
Cheers, Gene Heskett
--
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
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>
Erik Christiansen
2017-05-04 06:32:41 UTC
Permalink
Post by Gene Heskett
Post by Chris Albertson
RS422 is balanced and opt isolated at the Mesa card end so you likely
have better noise resistance then with SPI.
rs485 is the single ended cousin. Could a atom board keep up with that
with a pci-e rs422 card in it? That does have a bit of an attraction,
particularly from the noise safety dept. Silly Q: can the pi do rs422
over its gpio?
Hook a RS485/RS422 transceiver to a Pi's serial TXD & RXD, and terminate
each end of the twisted pair cable in 120 ohms, then it's done. All the
chip does is TTL/CMOS to differential Tx & Rx.

I bought some surplus DS3695A RS485/RS422 half-duplex transceivers a few
days ago for US30c each, but they draw over 27 mA, idling, - a MAX485
gets by on 300 uA, though it'll only do 2.5 Mb/s. The SN65HVD485 will do
10 Mb/s on long lines, and draw 1 to 2 mA. (They may be the one Jon
likes?)

Just watch pinout, driver enable logic, and whether it's full/half
duplex. The former has separate Tx & Rx cables (4 wires) vs 2 wires.

Incidentally, it's the RS485 which is multipoint - just in case you want
that, and go to put plastic down.

Erik
Gene Heskett
2017-05-04 16:26:41 UTC
Permalink
Post by Erik Christiansen
Post by Gene Heskett
Post by Chris Albertson
RS422 is balanced and opt isolated at the Mesa card end so you
likely have better noise resistance then with SPI.
rs485 is the single ended cousin. Could a atom board keep up with
that with a pci-e rs422 card in it? That does have a bit of an
attraction, particularly from the noise safety dept. Silly Q: can
the pi do rs422 over its gpio?
Hook a RS485/RS422 transceiver to a Pi's serial TXD & RXD, and
terminate each end of the twisted pair cable in 120 ohms, then it's
done. All the chip does is TTL/CMOS to differential Tx & Rx.
I bought some surplus DS3695A RS485/RS422 half-duplex transceivers a
few days ago for US30c each, but they draw over 27 mA, idling, - a
MAX485 gets by on 300 uA, though it'll only do 2.5 Mb/s. The
SN65HVD485 will do 10 Mb/s on long lines, and draw 1 to 2 mA. (They
may be the one Jon likes?)
Just watch pinout, driver enable logic, and whether it's full/half
duplex. The former has separate Tx & Rx cables (4 wires) vs 2 wires.
Incidentally, it's the RS485 which is multipoint - just in case you
want that, and go to put plastic down.
Erik
The ones I bought to play with are usb on one end, and 3 terminal on the
other. Bought them at the same time I bought that clone vfd, paying
about $3 ea at the time, only to find when I took it apart, that the
footprint for the seriel connection was totally absent from any of its
boards. So I'm running it directly with a spinx1, which is receiving a
PDM signal from the 7i90. Control works great until nearly 200hz, but
the motor inductance is so high its drawing under an amp/phase at 200
hz, and the torque is of course vanishingly small. I'd guess under
cutting loads, 120-140hz is about maximum. I'm sure I don't have it
well tuned yet, the lf cutoff at 15 hz seems too high as the start is
pretty brutal. With the clamps on the chuck pulled up tight so I can't
unscrew the chuck, I can have it doing 100 spindle revs using the lowest
belt position, type m4 to reverse, and its doing that same 100 revs in
reverse less than a second later, wash, rinse, repeat going back to m3.

My target is minimum overshoot for rigid tapping. I have some hal stuff I
can watch with a halmeter, tells me how many encoder counts it
overshoots so I can set the g33.1 params to not hit the bottom of the
blind hole & break the tap. Getting more familiar with pyvcp, I'll
probably add a number box to the gui at some point. I'd like it to
display the distance, but the k value fed to the g33.1 hasn't been found
so I can multiply it and convert the encoder counts into actual
overshoot distance traveled. Best I can display might be degrees turned
fwd since the reversal was given. I freeze that peak reading until the
next peck if using a peck cycle.

Sounds like if I buy some more rs422 stuffs, they ought to be based on
the SN65HVD485 chip. I'll be on the lookout. I am in favor of any
isolation from the noise I can get even if my current "lashup" is
working well. But on ebay its opto and slow and expen$ive, or usb and a
5 dollar bill. And those for sure aren't isolated. Or am I looking with
the wrong search terms? URL for something like you are writing about
plz.

Doing an experiment this day, might take a while. I managed to find the
root of the card on the pi, and with a terrabyte hd plugged into the pi,
cloned the one bootable card I have left to a 32Gb file on the hd. I
just brought a dead card, one of my readers, and that drive in here and
plugged it into my usb tree, and dd is now happily writing that 32Gb
image to a card that won't boot. Since the hd had an un-expanded
filesystem install of raspian jessie on it, I first had to find a way,
using the tools available on the pi, to expand the / filesystem from
3.2Gb to 850Gb, and do it without losing any data. Between parted and
resize2sf, I did appear to get it done. If it writes at the usual 4.5
megabytes/second, it will be done about midnight. :(

Cheers Erik, 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>
Nicklas Karlsson
2017-05-04 17:29:28 UTC
Permalink
Farnell have plenty of RS422 and RS485 drivers http://se.farnell.com/c/halvledare-ic-kretsar/drivkretsar-granssnitt/rs232-rs422-rs485-drivkretsar

Some extra capacitances might be a good idea to avoid voltage drop at power supply rail if there is capacitance between the differential lines. This is not a problem since capacitors are cheap but voltage drop might be and unless you think about it hard to figure out.




On Thu, 4 May 2017 16:32:41 +1000
Post by Erik Christiansen
Post by Gene Heskett
Post by Chris Albertson
RS422 is balanced and opt isolated at the Mesa card end so you likely
have better noise resistance then with SPI.
rs485 is the single ended cousin. Could a atom board keep up with that
with a pci-e rs422 card in it? That does have a bit of an attraction,
particularly from the noise safety dept. Silly Q: can the pi do rs422
over its gpio?
Hook a RS485/RS422 transceiver to a Pi's serial TXD & RXD, and terminate
each end of the twisted pair cable in 120 ohms, then it's done. All the
chip does is TTL/CMOS to differential Tx & Rx.
I bought some surplus DS3695A RS485/RS422 half-duplex transceivers a few
days ago for US30c each, but they draw over 27 mA, idling, - a MAX485
gets by on 300 uA, though it'll only do 2.5 Mb/s. The SN65HVD485 will do
10 Mb/s on long lines, and draw 1 to 2 mA. (They may be the one Jon
likes?)
Just watch pinout, driver enable logic, and whether it's full/half
duplex. The former has separate Tx & Rx cables (4 wires) vs 2 wires.
Incidentally, it's the RS485 which is multipoint - just in case you want
that, and go to put plastic down.
Erik
------------------------------------------------------------------------------
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
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--
Nicklas Karlsson <***@gmail.com>
Chris Albertson
2017-05-04 17:47:22 UTC
Permalink
Post by Erik Christiansen
Post by Gene Heskett
Post by Chris Albertson
RS422 is balanced and opt isolated at the Mesa card end so you likely
have better noise resistance then with SPI.
rs485 is the single ended cousin. Could a atom board keep up with that
with a pci-e rs422 card in it? That does have a bit of an attraction,
particularly from the noise safety dept. Silly Q: can the pi do rs422
over its gpio?
Hook a RS485/RS422 transceiver to a Pi's serial TXD & RXD, and terminate
each end of the twisted pair cable in 120 ohms, then it's done. All the
chip does is TTL/CMOS to differential Tx & Rx.
What is the maximum bit rate of the Pi's serial TXD & RXD? The 7i90 can
accept RS422 up to 10M bits/second. Can the Pi take advantage that?
Certainly an Intel PC could,

Yes I agree conversion is cheap and easy, You can buy the Max chips on
breakout boards with connectors for 50 cents each
ebay.com/itm/2PCS-MAX485-Module
<http://www.ebay.com/itm/2PCS-MAX485-Module-RS-485-Module-TTL-to-RS-485-Converter-For-Arduino/131694536431?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40130%26meid%3De519e5e6252c4e40b7d0fa2b19dcd5fc%26pid%3D100005%26rk%3D6%26rkt%3D6%26mehot%3Dag%26sd%3D112076449800>
In most cases it is best to buy the chips on boards with connectors. Saves
you from a lot of work.

People are using Cat5 (Ethernet cable) for all types of serial links now.
It just works better as most links are now balanced pairs.
Post by Erik Christiansen
I bought some surplus DS3695A RS485/RS422 half-duplex transceivers a few
days ago for US30c each, but they draw over 27 mA, idling, - a MAX485
--
Chris Albertson
Redondo Beach, California
Gene Heskett
2017-05-05 00:43:16 UTC
Permalink
On Wed, May 3, 2017 at 11:32 PM, Erik Christiansen
Post by Erik Christiansen
Post by Gene Heskett
Post by Chris Albertson
RS422 is balanced and opt isolated at the Mesa card end so you
likely have better noise resistance then with SPI.
rs485 is the single ended cousin. Could a atom board keep up with
that with a pci-e rs422 card in it? That does have a bit of an
attraction, particularly from the noise safety dept. Silly Q: can
the pi do rs422 over its gpio?
Hook a RS485/RS422 transceiver to a Pi's serial TXD & RXD, and
terminate each end of the twisted pair cable in 120 ohms, then it's
done. All the chip does is TTL/CMOS to differential Tx & Rx.
What is the maximum bit rate of the Pi's serial TXD & RXD? The 7i90
can accept RS422 up to 10M bits/second. Can the Pi take advantage
that? Certainly an Intel PC could,
I don't see why not. The spi runs with a 32 megahertz clock, thru 4 gpio
pins. Its a half-duplex protocol.
Yes I agree conversion is cheap and easy, You can buy the Max chips
on breakout boards with connectors for 50 cents each
ebay.com/itm/2PCS-MAX485-Module
<http://www.ebay.com/itm/2PCS-MAX485-Module-RS-485-Module-TTL-to-RS-48
5-Converter-For-Arduino/131694536431?_trksid=p2047675.c100005.m1851&_tr
kparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40130%26meid%3De5
19e5e6252c4e40b7d0fa2b19dcd5fc%26pid%3D100005%26rk%3D6%26rkt%3D6%26meho
t%3Dag%26sd%3D112076449800> In most cases it is best to buy the chips
on boards with connectors. Saves you from a lot of work.
I agree. The only problem with this board is that its rs485 only.
Unbalanced IOW. So theres goes some of the noise margin. And its data
rate must be pretty slow, its slew rated but not in any usefull way.
People are using Cat5 (Ethernet cable) for all types of serial links
now. It just works better as most links are now balanced pairs.
Post by Erik Christiansen
I bought some surplus DS3695A RS485/RS422 half-duplex transceivers a
few days ago for US30c each, but they draw over 27 mA, idling, - a
MAX485
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>
Erik Christiansen
2017-05-05 06:29:56 UTC
Permalink
Post by Gene Heskett
Post by Chris Albertson
Yes I agree conversion is cheap and easy, You can buy the Max chips
on breakout boards with connectors for 50 cents each
ebay.com/itm/2PCS-MAX485-Module
<http://www.ebay.com/itm/2PCS-MAX485-Module-RS-485-Module-TTL-to-RS-48
5-Converter-For-Arduino/131694536431?_trksid=p2047675.c100005.m1851&_tr
kparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40130%26meid%3De5
19e5e6252c4e40b7d0fa2b19dcd5fc%26pid%3D100005%26rk%3D6%26rkt%3D6%26meho
t%3Dag%26sd%3D112076449800> In most cases it is best to buy the chips
on boards with connectors. Saves you from a lot of work.
That's a good find. I may buy a few, just to breadboard with before I
get around to doing a board with ATmega328P and RS485 chip in one.
Post by Gene Heskett
I agree. The only problem with this board is that its rs485 only.
Unbalanced IOW.
No, not so, Gene. As already pointed out, RS485 is the multipoint
version of RS422, so balanced enough to pass a "walk the dotted line"
DUI test. ;-) Seriously, the 'A' and 'B' balanced line labels can be
seen on the PCB at the above link.

...
Post by Gene Heskett
And its data rate must be pretty slow, its slew rated but not in any
usefull way.
Ah, yes, the MAX485 will limit you to 2.5 Mb/s, and tolerance of
"improperly terminated cables" isn't something we'd need. The jabber
about "reduced EMI" sounds dubious too, as properly terminated twisted
pair ought not radiate alarmingly.
Post by Gene Heskett
Post by Chris Albertson
People are using Cat5 (Ethernet cable) for all types of serial links
now. It just works better as most links are now balanced pairs.
Yes, a reel of that stuff is buried somewhere in any good components
stash, I hold.

Erik
Gene Heskett
2017-05-05 14:52:35 UTC
Permalink
Post by Erik Christiansen
Post by Gene Heskett
Post by Chris Albertson
Yes I agree conversion is cheap and easy, You can buy the Max
chips on breakout boards with connectors for 50 cents each
ebay.com/itm/2PCS-MAX485-Module
<http://www.ebay.com/itm/2PCS-MAX485-Module-RS-485-Module-TTL-to-R
S-48
5-Converter-For-Arduino/131694536431?_trksid=p2047675.c100005.m185
1&_tr
kparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40130%26meid
%3De5
19e5e6252c4e40b7d0fa2b19dcd5fc%26pid%3D100005%26rk%3D6%26rkt%3D6%2
6meho t%3Dag%26sd%3D112076449800> In most cases it is best to buy
the chips on boards with connectors. Saves you from a lot of
work.
That's a good find. I may buy a few, just to breadboard with before I
get around to doing a board with ATmega328P and RS485 chip in one.
Post by Gene Heskett
I agree. The only problem with this board is that its rs485 only.
Unbalanced IOW.
No, not so, Gene. As already pointed out, RS485 is the multipoint
version of RS422, so balanced enough to pass a "walk the dotted line"
DUI test. ;-) Seriously, the 'A' and 'B' balanced line labels can be
seen on the PCB at the above link.
If the above link=
<http://www.ebay.com/itm/2PCS-MAX485-Module-RS-485-Module-TTL-to-RS-485-Converter-For-Arduino/131694536431?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40130%26meid%3De519e5e6252c4e40b7d0fa2b19dcd5fc%26pid%3D100005%26rk%3D6%26rkt%3D6%26mehot%3Dag%26sd%3D112076449800>

Yes, I see that now. That I assume means its half-duplex, but the spi is
too.

Thats a great price. There is also this 5 pack available:
<http://www.ebay.com/itm/5-MAX485-Module-RS485-Module-TTL-to-RS-485-Module-Converter-Board-TS/172176974958?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D40130%26meid%3D23e1633c0ba04d319d14c7ad895cf7e1%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D13169453>

Now, do we have an hm2 driver for the pi's gpio?

And in one of the adds it mentions slew rate limited, so I wonder what
its top speed is?

And if that slew rate is in the form of a capacitor, could it be removed?

Has anyone here used this one? What for & how fast?

Since this stuff is best described as volatile, I'll buy the 5 pack so
I've some to "play with".

Lots of questions...
Post by Erik Christiansen
...
Post by Gene Heskett
And its data rate must be pretty slow, its slew rated but not in any
usefull way.
Ah, yes, the MAX485 will limit you to 2.5 Mb/s, and tolerance of
"improperly terminated cables" isn't something we'd need. The jabber
about "reduced EMI" sounds dubious too, as properly terminated twisted
pair ought not radiate alarmingly.
Post by Gene Heskett
Post by Chris Albertson
People are using Cat5 (Ethernet cable) for all types of serial
links now. It just works better as most links are now balanced
pairs.
Yes, a reel of that stuff is buried somewhere in any good components
stash, I hold.
Erik
----------------------------------------------------------------------
-------- 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
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>
Chris Albertson
2017-05-05 15:29:32 UTC
Permalink
Post by Erik Christiansen
No, not so, Gene. As already pointed out, RS485 is the multipoint
Post by Erik Christiansen
version of RS422, so balanced enough to pass a "walk the dotted line"
DUI test. ;-) Seriously, the 'A' and 'B' balanced line labels can be
seen on the PCB at the above link.
If the above link=
<http://www.ebay.com/itm/2PCS-MAX485-Module-RS-485-Module-
TTL-to-RS-485-Converter-For-Arduino/131694536431?_trksid=
p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%
3DSIC.MBE%26ao%3D2%26asc%3D40130%26meid%3De519e5e6252c4e40b7d0fa2b19dc
d5fc%26pid%3D100005%26rk%3D6%26rkt%3D6%26mehot%3Dag%26sd%3D112076449800>
Yes, I see that now. That I assume means its half-duplex, but the spi is
too.
<http://www.ebay.com/itm/5-MAX485-Module-RS485-Module-
TTL-to-RS-485-Module-Converter-Board-TS/172176974958?_trksid=p2047675.
c100005.m1851&_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%
3D2%26asc%3D40130%26meid%3D23e1633c0ba04d319d14c7ad895c
f7e1%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D13169453>
Now, do we have an hm2 driver for the pi's gpio?
And in one of the adds it mentions slew rate limited, so I wonder what
its top speed is?
The 585 is "limited slew rate" so as to minimize EMI. This limits speed
to about 250K buad

Other version of the chip with different numbers can go to about 10X faster
2.5M baud but then you are sending square waves down a wire and radiating
the bits into space. Twist the pairs and shield it.

I pointed out that product on eBay as an example of what you can get.
Just about ANYTHING is available on a little breakout board for a price
close enough to free that you should not care. (yes 50 cents or free, it
is about the same thing)

Just use normal RS422 drivers. You can find those too. Search eBay based
on the MAX chip part number.

Br sure to read the data sheet for the chips involved. These Chinese
vendors know NOTHING about what they are selling. The vendors are
typically some guy working out of his apartment.
Post by Erik Christiansen
And if that slew rate is in the form of a capacitor, could it be removed?
Has anyone here used this one? What for & how fast?
Since this stuff is best described as volatile, I'll buy the 5 pack so
I've some to "play with".
Lots of questions...
Post by Erik Christiansen
...
Post by Gene Heskett
And its data rate must be pretty slow, its slew rated but not in any
usefull way.
Ah, yes, the MAX485 will limit you to 2.5 Mb/s, and tolerance of
"improperly terminated cables" isn't something we'd need. The jabber
about "reduced EMI" sounds dubious too, as properly terminated twisted
pair ought not radiate alarmingly.
Post by Gene Heskett
Post by Chris Albertson
People are using Cat5 (Ethernet cable) for all types of serial
links now. It just works better as most links are now balanced
pairs.
Yes, a reel of that stuff is buried somewhere in any good components
stash, I hold.
Erik
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_______________________________________________
Emc-users mailing list
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Cheers, Gene Heskett
--
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
_______________________________________________
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--
Chris Albertson
Redondo Beach, California
andy pugh
2017-05-05 15:45:49 UTC
Permalink
Post by Gene Heskett
Since this stuff is best described as volatile, I'll buy the 5 pack so
I've some to "play with".
What do you intend to do with this RS485 interface?
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
Gene Heskett
2017-05-05 21:47:05 UTC
Permalink
Post by andy pugh
Post by Gene Heskett
Since this stuff is best described as volatile, I'll buy the 5 pack
so I've some to "play with".
What do you intend to do with this RS485 interface?
I don't know yet Andy. Gotta see what it can do speedwise first.

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>
Nicklas Karlsson
2017-05-05 22:02:49 UTC
Permalink
Post by Gene Heskett
Post by andy pugh
Post by Gene Heskett
Since this stuff is best described as volatile, I'll buy the 5 pack
so I've some to "play with".
What do you intend to do with this RS485 interface?
I don't know yet Andy. Gotta see what it can do speedwise first.
There are plenty of Profibus devices out there so it might be very useful. Both simple IO and motor drivers.
andy pugh
2017-05-05 22:27:52 UTC
Permalink
Post by Nicklas Karlsson
Post by Gene Heskett
I don't know yet Andy. Gotta see what it can do speedwise first.
There are plenty of Profibus devices out there so it might be very useful. Both simple IO and motor drivers.
I just want to repeat that there is _no_ existing off-the-shelf
real-time HAL serial support other than the Mesa Smart-Serial.

(And, incidentally, smart-serial is working very nicely with the
non-Mesa STMBL, it's rather a nice protocol for motion control as it
incoporates a device discovery mode)
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
Gene Heskett
2017-05-07 20:56:13 UTC
Permalink
Post by Gene Heskett
Post by andy pugh
Post by Gene Heskett
Since this stuff is best described as volatile, I'll buy the 5
pack so I've some to "play with".
What do you intend to do with this RS485 interface?
I don't know yet Andy. Gotta see what it can do speedwise first.
Cheers, Gene Heskett
Well, plugged into a usb port on that old slow sheldon, I get rise and
fall times of the A signal out in the 16ns area. And I'll have to plead
oldtimers because I could not remember the name of the serial port
config daemon, stty, which is currently doing 9600 baud. Now to go back
out and see how fast I can make it run. Back eventually.

It seems that "stty -F /dev/ttyUSB0 460800" still sends pretty well
defined data, which my scope says is a red hair over 2 us for character
time, and inverts that to 460.2 kilo baud.

Now, the cat5 socket on the 7i90 is an 8 line, even POE, full duplex, A&B
send and separate A&B rx. Since all these so-called adaptors are only 3
wire half-duplex, and assuming the use of a regular db9 serial port
with "7 wire protocol which is full duplex", is there anyone making a
plug and play, using 2 of these adaptors, gizmo that just works?

My attempt to make a new card for the pi, ends up with exactly the same
error. Thats 5 passes at recovering what was working quite well the
morning of 2 May. No one can believe me that the 13 file update done
later that morning, bricks the pi's.

I'm very impressed with the lack of data on the up-shop.net web site as
to just what these atom powered things have, they don't even say how
wide the gpio count is, so I may have bought a very lightweight
paperweight, but the card was accepted for one just like Erik said he
had bought. 2 gigs of ram, 16gigs of eMMC for a disk drive. $124
shipped. With suitable drivers, all running x86/intel code, its
promising. The forum is loaded with this and that don't work messages
though. I don't see a debian for downloading but I'd prefer it, jessie
is close to EOL, and rumors are saying stretch is fairly stable now.
Theres some sort of a ubuntu I never heard of, yocto (whats that?) and
whatever is running the fawncy phones these days.

Cheers all; Gotta hit the grocery store. Out of eggs.

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>
andy pugh
2017-05-11 12:54:14 UTC
Permalink
Post by Gene Heskett
Theres some sort of a ubuntu I never heard of, yocto (whats that?) and
whatever is running the fawncy phones these days.
Yocto is a Linux (and a build system) targetting embedded systems.
I think that the Linux part of Yocto is actually called Poky.

https://www.yoctoproject.org/

It seems to me that it could be a good fit for LinuxCNC, and I have
been trying to persuade the architect of the project to CNC his
milling machine for that very reason.
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
Gene Heskett
2017-05-11 14:22:24 UTC
Permalink
Post by andy pugh
Post by Gene Heskett
Theres some sort of a ubuntu I never heard of, yocto (whats that?)
and whatever is running the fawncy phones these days.
Yocto is a Linux (and a build system) targetting embedded systems.
I think that the Linux part of Yocto is actually called Poky.
https://www.yoctoproject.org/
It seems to me that it could be a good fit for LinuxCNC, and I have
been trying to persuade the architect of the project to CNC his
milling machine for that very reason.
I went to the site, and seemed to not be able to find any reference to
the architectures it may, or may not run on. A specific search
for "raspberry pi" with spelling variations all came back empty.

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>
andy pugh
2017-05-11 14:51:39 UTC
Permalink
Post by Gene Heskett
I went to the site, and seemed to not be able to find any reference to
the architectures it may, or may not run on.
They have a board support package for Beaglebone
https://www.yoctoproject.org/downloads/bsps?release=All&processer%5B%5D=21&title=
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
Nicklas Karlsson
2017-05-05 15:45:28 UTC
Permalink
Post by Erik Christiansen
Post by Gene Heskett
And its data rate must be pretty slow, its slew rated but not in any
usefull way.
Ah, yes, the MAX485 will limit you to 2.5 Mb/s, and tolerance of
"improperly terminated cables" isn't something we'd need. The jabber
about "reduced EMI" sounds dubious too, as properly terminated twisted
pair ought not radiate alarmingly.
Faster signals and longer cables make termination more important. With cables short enough and/or signals slow enough termination is less important.
Nicklas Karlsson
2017-05-05 15:42:20 UTC
Permalink
Post by Gene Heskett
Post by Chris Albertson
Post by Erik Christiansen
Post by Gene Heskett
Post by Chris Albertson
RS422 is balanced and opt isolated at the Mesa card end so you
likely have better noise resistance then with SPI.
rs485 is the single ended cousin. Could a atom board keep up with
that with a pci-e rs422 card in it? That does have a bit of an
attraction, particularly from the noise safety dept. Silly Q: can
the pi do rs422 over its gpio?
Hook a RS485/RS422 transceiver to a Pi's serial TXD & RXD, and
terminate each end of the twisted pair cable in 120 ohms, then it's
done. All the chip does is TTL/CMOS to differential Tx & Rx.
What is the maximum bit rate of the Pi's serial TXD & RXD? The 7i90
can accept RS422 up to 10M bits/second. Can the Pi take advantage
that? Certainly an Intel PC could,
I don't see why not. The spi runs with a 32 megahertz clock, thru 4 gpio
pins. Its a half-duplex protocol.
SPI use separate clock signal while and one data channel in each direction although but it is of course no problem to only use one. RS422 do not have a separate clock signal and instead synchonize to the flanks of the signal, most probably to the start of the first flank. RS244 might be able to receive data sent from SPI level is correct and start/stop is inserted but not the opposite.
Post by Gene Heskett
I agree. The only problem with this board is that its rs485 only.
Unbalanced IOW. So theres goes some of the noise margin. And its data
rate must be pretty slow, its slew rated but not in any usefull way.
Ideally it should be isolated and shielded differential twisted pair but if length of cable is short and no noise there is no need. It is common to use high speed SPI communication on circuit board single ended without drive but here distance is short and usually there is a ground plane all the way close the signal.
andy pugh
2017-05-04 11:40:20 UTC
Permalink
Post by Chris Albertson
You'd get the best bandwidth by using RS422 but the cost is higher because
you'd need the intel PC and the serial and graphic cards.
You would also need to Hostmot2 driver layer for serial, and there isn't one.

The 7i90 can connect to LinuxCNC with the parport now, using existing drivers.
And it is perfectly fast enough for the job at hand. (I certainly
never noticed any lack of bandwidth with my 7i43)
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
Gene Heskett
2017-05-04 16:33:01 UTC
Permalink
Post by andy pugh
Post by Chris Albertson
You'd get the best bandwidth by using RS422 but the cost is higher
because you'd need the intel PC and the serial and graphic cards.
You would also need to Hostmot2 driver layer for serial, and there isn't one.
The 7i90 can connect to LinuxCNC with the parport now, using existing
drivers. And it is perfectly fast enough for the job at hand. (I
certainly never noticed any lack of bandwidth with my 7i43)
But the only box I have that fits that description is a huge swarf magnet
Dell with an old slow p4 in it. I've no clue how fast its parport might
be. The only reason I haven't binned it is its my programmer for the
7i90's.

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>
andy pugh
2017-05-04 16:41:32 UTC
Permalink
Post by Gene Heskett
But the only box I have that fits that description is a huge swarf magnet
Dell with an old slow p4 in it. I've no clue how fast its parport might
be. The only reason I haven't binned it is its my programmer for the
7i90's.
But the question you asked was about what new x86 board to get to
drive the 7i90.
So, buy a new, fanless, Mini-ITX board with onboard parport.
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
dragon
2017-05-04 16:51:02 UTC
Permalink
In case you are interested I have tried both the AsRock Q1900-ITX and
Q1900-M. Both have a par port header on the board and worked fine with a
Pico Universal PWM card and had a very acceptable jitter even without
trying to tweak things.

I don't see why they wouldn't work with the 7i90 as well.
Post by andy pugh
Post by Gene Heskett
But the only box I have that fits that description is a huge swarf magnet
Dell with an old slow p4 in it. I've no clue how fast its parport might
be. The only reason I haven't binned it is its my programmer for the
7i90's.
But the question you asked was about what new x86 board to get to
drive the 7i90.
So, buy a new, fanless, Mini-ITX board with onboard parport.
Gene Heskett
2017-05-04 17:21:43 UTC
Permalink
Post by dragon
In case you are interested I have tried both the AsRock Q1900-ITX and
Q1900-M. Both have a par port header on the board and worked fine with
a Pico Universal PWM card and had a very acceptable jitter even
without trying to tweak things.
I don't see why they wouldn't work with the 7i90 as well.
They should. And its possible it might fit in the box I bought. $70 +
some memory, about 2 Gb in 2 sticks. And a sata SSD. $200 max. But I'm
going to keep plugging away at this pi since I've learned a bit about
it. The problem now, and I pounding on the forum, is that one of the 15
updated files over the weekend renders it unbootable. And one of them
replaced at least half the contents of the /boot partition.

That, and the buildbot is down, has been since Wednesday I think.
Post by dragon
Post by andy pugh
Post by Gene Heskett
But the only box I have that fits that description is a huge swarf
magnet Dell with an old slow p4 in it. I've no clue how fast its
parport might be. The only reason I haven't binned it is its my
programmer for the 7i90's.
But the question you asked was about what new x86 board to get to
drive the 7i90.
So, buy a new, fanless, Mini-ITX board with onboard parport.
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>
Gene Heskett
2017-05-04 16:51:23 UTC
Permalink
Post by andy pugh
Post by Gene Heskett
But the only box I have that fits that description is a huge swarf
magnet Dell with an old slow p4 in it. I've no clue how fast its
parport might be. The only reason I haven't binned it is its my
programmer for the 7i90's.
But the question you asked was about what new x86 board to get to
drive the 7i90.
So, buy a new, fanless, Mini-ITX board with onboard parport.
Them's pretty sparsely listed at newegg or tigerdirect. The onboard
parport is rapidly disappearing. URL for a suitable board plz?

Thanks Andy

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>
Jon Elson
2017-05-04 03:39:20 UTC
Permalink
Post by Gene Heskett
Sure, but whats the bandwidth of a parport? 50 kilobaud equ maybe.
Actually, 500 K bytes/second is easy on a standard parport,
today.

Jon
Gregg Eshelman
2017-05-04 04:07:08 UTC
Permalink
https://www.digikey.com/products/en/embedded-computers/single-board-computers-sbcs/933
Post by Gene Heskett
What x86 board, suitably small but not that outpriced yudoo thingy, will
run linuxcnc well AND can do the spi thing?
I doubt that you will find an x86 PC with SPI. (though I could be wrong).

But the 7i90 can also do EPP.
Chris Albertson
2017-05-03 21:29:55 UTC
Permalink
If you go with an Intel board you'd like be using Ethernet, not SPI to
connect a Mesa card. Ethernet is really better anyway as it uses
standardized connectors, off the shelf cable and can run distances over 100
meters.

There is of course not end to the number of Intel boards. But you might
want to select one where the on-board graphics can be disabled ad them you
get a good graphic card that supports OpenGL.
Post by Gene Heskett
Greetings;
What x86 board, suitably small but not that outpriced yudoo thingy, will
run linuxcnc well AND can do the spi thing?
Cheers, Gene Heskett
--
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
https://lists.sourceforge.net/lists/listinfo/emc-users
--
Chris Albertson
Redondo Beach, California
Jon Elson
2017-05-04 01:41:34 UTC
Permalink
Post by Gene Heskett
Greetings;
What x86 board, suitably small but not that outpriced yudoo thingy, will
run linuxcnc well AND can do the spi thing?
Cheers, Gene Heskett
Well, the various versions of the Beagle Bone run the
Machinekit fork of LinuxCNC fairly well.
The Bone has a lot more I/O available, including hardware
SPI interfaces.

I don't know any X86 boards that have built-in SPI available
externally.

Jon
Gene Heskett
2017-05-04 02:28:52 UTC
Permalink
Post by Jon Elson
Post by Gene Heskett
Greetings;
What x86 board, suitably small but not that outpriced yudoo thingy,
will run linuxcnc well AND can do the spi thing?
Cheers, Gene Heskett
Well, the various versions of the Beagle Bone run the
Machinekit fork of LinuxCNC fairly well.
The Bone has a lot more I/O available, including hardware
SPI interfaces.
I don't know any X86 boards that have built-in SPI available
externally.
Jon
The killer in the beaglebone soup is the cost of the "capes". You've over
$200 plus psu's etc before it can turn 2 motors at the same time. I
don't begrudge the guys trying to make enough to buy their beer, but a
7i90 for a bit over $60, simply blows most of the capes I've looked up
into the next drainage.

The spi bus out of the pi runs at 32 megabaud, sending 4 byte packets 4
bytes at a time with an extra stop bit between 8 bit bytes. Thats the
equ of a 32bit word at 4 megahertz. The parport would have to run at 8
megabytes/second to match that amount of data in that same amount of
time. I think... At any rate, that's an order of magnitude faster than
the parport can legally do it, it just does not have the ability to
deliver the slew rates down the cable that would need. 10% of whats
needed is all that is legally available Does linuxcnc have the ability
to work over that slow a com channel? Seems like that would be pushing
our luck.
Post by Jon Elson
----------------------------------------------------------------------
-------- 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
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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>
Eric Keller
2017-05-04 02:47:32 UTC
Permalink
Post by Gene Heskett
The killer in the beaglebone soup is the cost of the "capes". You've over
$200 plus psu's etc before it can turn 2 motors at the same time.
The beaglebone blue has dc motor outputs and encoder inputs for $80.
Getting cnc on it would be an exercise for someone though.
Jon Elson
2017-05-04 03:44:02 UTC
Permalink
Post by Gene Heskett
The killer in the beaglebone soup is the cost of the "capes". You've over
$200 plus psu's etc before it can turn 2 motors at the same time.
Umm, the CRAMPS board is $79.95, and I sell the 8825 drivers
for $5 each, but I get them from China for about $1.30
each. The BeagleBone is $55, but there are some that have
the HDMI pulled out for $39 from SEEED, I think.
The CRAMPS can run 6 motors, plus 5 PWM controlled DC
devices, plus 6 limit switch inputs and 4 analog inputs.
(Disclaimer: I make the CRAMPS boards.)
Post by Gene Heskett
I
don't begrudge the guys trying to make enough to buy their beer, but a
7i90 for a bit over $60, simply blows most of the capes I've looked up
into the next drainage.
The spi bus out of the pi runs at 32 megabaud, sending 4 byte packets 4
bytes at a time with an extra stop bit between 8 bit bytes. Thats the
equ of a 32bit word at 4 megahertz. The parport would have to run at 8
megabytes/second to match that amount of data in that same amount of
time. I think... At any rate, that's an order of magnitude faster than
the parport can legally do it, it just does not have the ability to
deliver the slew rates down the cable that would need. 10% of whats
needed is all that is legally available Does linuxcnc have the ability
to work over that slow a com channel? Seems like that would be pushing
our luck.
And, the Beagle has 2 (I think) SPIs that can be brought out
to external pins.

Jon
Gene Heskett
2017-05-04 04:36:45 UTC
Permalink
Post by Jon Elson
Post by Gene Heskett
The killer in the beaglebone soup is the cost of the "capes". You've
over $200 plus psu's etc before it can turn 2 motors at the same
time.
Umm, the CRAMPS board is $79.95, and I sell the 8825 drivers
for $5 each, but I get them from China for about $1.30
each.
The 8825 does what? I need to take another look at your site I guess.
Post by Jon Elson
The BeagleBone is $55,
And how many cores & how fast is its arm?
Post by Jon Elson
but there are some that have
the HDMI pulled out for $39 from SEEED, I think.
The CRAMPS can run 6 motors, plus 5 PWM controlled DC
devices, plus 6 limit switch inputs and 4 analog inputs.
(Disclaimer: I make the CRAMPS boards.)
That sounds quite a bit more palatable.
Post by Jon Elson
Post by Gene Heskett
I
don't begrudge the guys trying to make enough to buy their beer, but
a 7i90 for a bit over $60, simply blows most of the capes I've
looked up into the next drainage.
The spi bus out of the pi runs at 32 megabaud, sending 4 byte
packets 4 bytes at a time with an extra stop bit between 8 bit
bytes. Thats the equ of a 32bit word at 4 megahertz. The parport
would have to run at 8 megabytes/second to match that amount of data
in that same amount of time. I think... At any rate, that's an order
of magnitude faster than the parport can legally do it, it just does
not have the ability to deliver the slew rates down the cable that
would need. 10% of whats needed is all that is legally available
Does linuxcnc have the ability to work over that slow a com channel?
Seems like that would be pushing our luck.
And, the Beagle has 2 (I think) SPIs that can be brought out
to external pins.
How fast can they run?

Thanks Jon. But I'm past due to get requainted with my pillow. Tomorrow.
With luck, dd will have imaged the only working u-sd card I have left
that will boot that pi. That was tricky as I had to expand a 3+ gigabyte
partition on a terabyte drive to 850Gb, without losing any data already
on it. Then I have room to image the sd card so I can make more copies
on 4 other cards that won't boot anymore.
Post by Jon Elson
Jon
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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>
Jon Elson
2017-05-04 17:14:07 UTC
Permalink
Post by Gene Heskett
Post by Jon Elson
Post by Gene Heskett
The killer in the beaglebone soup is the cost of the "capes". You've
over $200 plus psu's etc before it can turn 2 motors at the same
time.
Umm, the CRAMPS board is $79.95, and I sell the 8825 drivers
for $5 each, but I get them from China for about $1.30
each.
The 8825 does what? I need to take another look at your site I guess.
2 A 35 V stepper driver.
Post by Gene Heskett
Post by Jon Elson
The BeagleBone is $55,
And how many cores & how fast is its arm?
I think it is only one core, 1 GHz. Works fine for
Machinekit/LinuxCNC control of Cartesian machine, but ssh -X
connection from a machine with a screen is noticeably slower
than an X86 PC with directly-connected screen.

The Beagle Bone has 2 PRU processors (200 MHz real time
32-bit CPUs) that Charles Steinkuehler set up the framework
for so that LinuxCNC can do fast stepping, PWM and encoder
counting. Not quite FPGA performance, but WAY faster than
software stepping. So, that relieves the ARM CPU from the
base thread tasks.

Jon
Andrew
2017-05-04 17:41:31 UTC
Permalink
Post by Jon Elson
Post by Gene Heskett
Post by Jon Elson
The BeagleBone is $55,
And how many cores & how fast is its arm?
I think it is only one core, 1 GHz. Works fine for
Machinekit/LinuxCNC control of Cartesian machine, but ssh -X
connection from a machine with a screen is noticeably slower
than an X86 PC with directly-connected screen.
I personally find BBB pretty interesting, PRU amazing and so on.
But what BBB really lacks is computing power. It's just terribly slow,
unfortunately. RPi 3 is probably 3 times faster and it's still not fast
enough.
Also it's pretty disappointing that Machinekit is not going to merge
joint_axes...
While I own 2 BBBs (and CRAMPS which I have not even used yet), I almost
gave up on this stuff.

OTOH I still hope for RPi & 7i90 to control at least some DIY robots.
Gene Heskett
2017-05-04 21:38:26 UTC
Permalink
Post by Jon Elson
Post by Gene Heskett
Post by Jon Elson
Post by Gene Heskett
The killer in the beaglebone soup is the cost of the "capes".
You've over $200 plus psu's etc before it can turn 2 motors at the
same time.
Umm, the CRAMPS board is $79.95, and I sell the 8825 drivers
for $5 each, but I get them from China for about $1.30
each.
The 8825 does what? I need to take another look at your site I guess.
2 A 35 V stepper driver.
Whereas I'm at 43 volts and 5 amps on x(8 wire motor in parallel), 65V
and around 3.5A on z.

And fixing to add another 20 volts to x, its tapped out at about 40 ipm.
Fairly small fine threaded ball screw.
Post by Jon Elson
Post by Gene Heskett
Post by Jon Elson
The BeagleBone is $55,
And how many cores & how fast is its arm?
I think it is only one core, 1 GHz. Works fine for
Machinekit/LinuxCNC control of Cartesian machine, but ssh -X
connection from a machine with a screen is noticeably slower
than an X86 PC with directly-connected screen.
Where this pi has 4 cores, 64 bit, and is running at 1.2GHz
And twice the memory. Needs more yet. So I think I'll stick with it
unless this last experiment fails. dd is still munching away at creating
a clone of the only u-sd that will still boot it.

Then 2 boxes of deck stuff just walked up and plopped themselves down on
the front deck, which I am suspecting I'll need to modify the gazebo as
its too tall to fit under the roof overhang. Might wind up ripping out
some greenery and extending the deck, outward by a foot or so and east 5
feet as it will block the front door otherwise. Fun and games with
2x8's for framing and 2x4's for flooring.

If it ever happens. Dee said no. So I've spent the afternoon assembling
the deck furniture, which came in flatish pieces. Got the corner chair
piece and 2 chairs, but still have 2 in the box when it started a light
rain, and my back said enough already. So dinner is warming in the
microwave.
Post by Jon Elson
The Beagle Bone has 2 PRU processors (200 MHz real time
32-bit CPUs) that Charles Steinkuehler set up the framework
for so that LinuxCNC can do fast stepping, PWM and encoder
counting. Not quite FPGA performance, but WAY faster than
software stepping. So, that relieves the ARM CPU from the
base thread tasks.
Jon
Thanks Jon.

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>
Steve Traugott
2017-05-05 00:42:27 UTC
Permalink
Has anyone tried an (Intel) Edison yet? It's an x86 machine, and comes in
at $100 if you add the arduino-pinout carrier board to give you all the I/O
pins: https://www.sparkfun.com/products/13097
Post by Gene Heskett
Post by Jon Elson
Post by Gene Heskett
Post by Jon Elson
Post by Gene Heskett
The killer in the beaglebone soup is the cost of the "capes".
You've over $200 plus psu's etc before it can turn 2 motors at the
same time.
Umm, the CRAMPS board is $79.95, and I sell the 8825 drivers
for $5 each, but I get them from China for about $1.30
each.
The 8825 does what? I need to take another look at your site I guess.
2 A 35 V stepper driver.
Whereas I'm at 43 volts and 5 amps on x(8 wire motor in parallel), 65V
and around 3.5A on z.
And fixing to add another 20 volts to x, its tapped out at about 40 ipm.
Fairly small fine threaded ball screw.
Post by Jon Elson
Post by Gene Heskett
Post by Jon Elson
The BeagleBone is $55,
And how many cores & how fast is its arm?
I think it is only one core, 1 GHz. Works fine for
Machinekit/LinuxCNC control of Cartesian machine, but ssh -X
connection from a machine with a screen is noticeably slower
than an X86 PC with directly-connected screen.
Where this pi has 4 cores, 64 bit, and is running at 1.2GHz
And twice the memory. Needs more yet. So I think I'll stick with it
unless this last experiment fails. dd is still munching away at creating
a clone of the only u-sd that will still boot it.
Then 2 boxes of deck stuff just walked up and plopped themselves down on
the front deck, which I am suspecting I'll need to modify the gazebo as
its too tall to fit under the roof overhang. Might wind up ripping out
some greenery and extending the deck, outward by a foot or so and east 5
feet as it will block the front door otherwise. Fun and games with
2x8's for framing and 2x4's for flooring.
If it ever happens. Dee said no. So I've spent the afternoon assembling
the deck furniture, which came in flatish pieces. Got the corner chair
piece and 2 chairs, but still have 2 in the box when it started a light
rain, and my back said enough already. So dinner is warming in the
microwave.
Post by Jon Elson
The Beagle Bone has 2 PRU processors (200 MHz real time
32-bit CPUs) that Charles Steinkuehler set up the framework
for so that LinuxCNC can do fast stepping, PWM and encoder
counting. Not quite FPGA performance, but WAY faster than
software stepping. So, that relieves the ARM CPU from the
base thread tasks.
Jon
Thanks Jon.
Cheers, Gene Heskett
--
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
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Chris Albertson
2017-05-05 04:25:28 UTC
Permalink
No. The one to use is
amazon.com/dp/B00K53CQK4
<https://www.amazon.com/dp/B00K53CQK4/ref=psdc_1048424_t1_B00L7AWOEC>
It is $70 and takes arduino spec'd shields. These kind of products are
good if building a portable battery powered device.

But really, a $50 ITX size Atom board is even more powerful at less cost.
Post by Steve Traugott
Has anyone tried an (Intel) Edison yet? It's an x86 machine, and comes in
at $100 if you add the arduino-pinout carrier board to give you all the I/O
pins: https://www.sparkfun.com/products/13097
Post by Gene Heskett
Post by Jon Elson
Post by Gene Heskett
Post by Jon Elson
Post by Gene Heskett
The killer in the beaglebone soup is the cost of the "capes".
You've over $200 plus psu's etc before it can turn 2 motors at the
same time.
Umm, the CRAMPS board is $79.95, and I sell the 8825 drivers
for $5 each, but I get them from China for about $1.30
each.
The 8825 does what? I need to take another look at your site I guess.
2 A 35 V stepper driver.
Whereas I'm at 43 volts and 5 amps on x(8 wire motor in parallel), 65V
and around 3.5A on z.
And fixing to add another 20 volts to x, its tapped out at about 40 ipm.
Fairly small fine threaded ball screw.
Post by Jon Elson
Post by Gene Heskett
Post by Jon Elson
The BeagleBone is $55,
And how many cores & how fast is its arm?
I think it is only one core, 1 GHz. Works fine for
Machinekit/LinuxCNC control of Cartesian machine, but ssh -X
connection from a machine with a screen is noticeably slower
than an X86 PC with directly-connected screen.
Where this pi has 4 cores, 64 bit, and is running at 1.2GHz
And twice the memory. Needs more yet. So I think I'll stick with it
unless this last experiment fails. dd is still munching away at creating
a clone of the only u-sd that will still boot it.
Then 2 boxes of deck stuff just walked up and plopped themselves down on
the front deck, which I am suspecting I'll need to modify the gazebo as
its too tall to fit under the roof overhang. Might wind up ripping out
some greenery and extending the deck, outward by a foot or so and east 5
feet as it will block the front door otherwise. Fun and games with
2x8's for framing and 2x4's for flooring.
If it ever happens. Dee said no. So I've spent the afternoon assembling
the deck furniture, which came in flatish pieces. Got the corner chair
piece and 2 chairs, but still have 2 in the box when it started a light
rain, and my back said enough already. So dinner is warming in the
microwave.
Post by Jon Elson
The Beagle Bone has 2 PRU processors (200 MHz real time
32-bit CPUs) that Charles Steinkuehler set up the framework
for so that LinuxCNC can do fast stepping, PWM and encoder
counting. Not quite FPGA performance, but WAY faster than
software stepping. So, that relieves the ARM CPU from the
base thread tasks.
Jon
Thanks Jon.
Cheers, Gene Heskett
--
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
https://lists.sourceforge.net/lists/listinfo/emc-users
------------------------------------------------------------
------------------
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
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--
Chris Albertson
Redondo Beach, California
Chris Albertson
2017-05-04 16:10:28 UTC
Permalink
Why is this so hard and expensive? I view this question as a huge business
opportunity. The cost and time involved in setting up a CNC system is MUCH
more than it should be. Fix that problem and you'll be rich, The cost
could be reduced by maybe a factor of 8x. Customers would be happy to see
a 4X reduction and you pocket the difference.

I am in my other hobby building robots. It is just like CNC, really except
more axis and the motions are not pre-programed.

So on my desk right now are four DC motors with quadrature encoders. They
are literally strapped to a bread board. I'm driving them with about $15
worth of electronics. I'm doing motion planning and using ultrasonic
"limit switches" It needn't be expensive. Machine tools electronics
tend to be expensive only because people say "What the heck it's a $40,000
mill what does $2,000 worth of electronics add to the total cost?" But
when you look at what you really need, a micro controller and some 10 cent
MOSFET switches it comes to under $20.

Part of the cost comes from the fact that we (especially those building up
systems from LinuxCNC/Machinekit) are using a set of lego blocks that don't
match. Some blocks of square bumps and round hole and they don't lock
together so we spend time making adapters. For example your computer
makes step and direction pulses but a bipolar stepping motor wants to see
voltages on it's four lead wires. Why not have the computer computer the
voltages?

That said if you can bill customers at an hourly rate it is well worth
$2,000 or more to get the project moved forward and working by a few days.
But a hobbyist is not turning away one hour of billable time for every
hour he fusses with his mill.

So, if this is a hobby and some part is expensive, skip it. There are
always lower cost DIY alternatives. You can trade cost for time. Or in
my case I care a lot about size rune weight and power

An example. Decoding quadrate signals. All of the ARM chips made by ST
Micro have quadrature decoding hardware on-chip. Typically four of more
sets. These will completely solve the problem in hardware and the chips
cost under $3, or $13 if you buy them on a usable PCB that has herders, USB
connectors and so on. Mesa boards cost about $100 give or take but you can
buy the same FPGA on a generic brand board for $13. What happens is that
when it is marketed as a machine tool component the price goes up by a
factor of at least 8X.

One should be able to build an integrated machine controller for about $150
that does visualization and controls four motor axis. The visualization
and controls could live on a iPad or phone and the real time control on a
small uP or FPGA. A modern tablet or phone is more then enough to run
Machine kit or the like and a $3 ARM M4 chip can do real-time enough for a
multi-axis industrial machine.

Such a product would be "disruptive" in the marketplace.


An example of someone who is set to make a mint in the 3D printer industry
has come up with a way to reduce the cost and complexity by about 4X.
First, the controller is a normal cell phone that you lay on your desk face
up. The printer is stacked over the phone. The communication path is the
light on the cellphone's screen. An LCD screen is a VERY high bandwidth
channel. and moving the "brains" out or your product saves the cost if
providing the "brains". Some other cost saving features are using just
one motor rather then the normal three motors and making the unit from
injection molded plastic rather than machined metal. They can retail tiny
size printer for about $100.

Point is that there is a huge opportunity every thine you see something
that is more complex and expensive than it needs to be. Building a CNC
machine is 100% full into this category.

Uber of course was another example. Why place a complex taxi meter in a
taxi cab when GPS software can compute the distance and time? Why hire a
dispatch office when electronic messaging can do the job with no humans.
Why even buy taxi cabs when every one of your employees already owns a car?
Why handle cash and credit cards when we can do electronic billing? They
got the cost down to nearly zero and they pocket most of the savings.
Post by Gene Heskett
Post by Jon Elson
Post by Gene Heskett
Greetings;
What x86 board, suitably small but not that outpriced yudoo thingy,
will run linuxcnc well AND can do the spi thing?
Cheers, Gene Heskett
Well, the various versions of the Beagle Bone run the
Machinekit fork of LinuxCNC fairly well.
The Bone has a lot more I/O available, including hardware
SPI interfaces.
I don't know any X86 boards that have built-in SPI available
externally.
Jon
The killer in the beaglebone soup is the cost of the "capes". You've over
$200 plus psu's etc before it can turn 2 motors at the same time. I
don't begrudge the guys trying to make enough to buy their beer, but a
7i90 for a bit over $60, simply blows most of the capes I've looked up
into the next drainage.
The spi bus out of the pi runs at 32 megabaud, sending 4 byte packets 4
bytes at a time with an extra stop bit between 8 bit bytes. Thats the
equ of a 32bit word at 4 megahertz. The parport would have to run at 8
megabytes/second to match that amount of data in that same amount of
time. I think... At any rate, that's an order of magnitude faster than
the parport can legally do it, it just does not have the ability to
deliver the slew rates down the cable that would need. 10% of whats
needed is all that is legally available Does linuxcnc have the ability
to work over that slow a com channel? Seems like that would be pushing
our luck.
Post by Jon Elson
----------------------------------------------------------------------
-------- 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
https://lists.sourceforge.net/lists/listinfo/emc-users
Cheers, Gene Heskett
--
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
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--
Chris Albertson
Redondo Beach, California
andy pugh
2017-05-04 16:39:44 UTC
Permalink
Post by Chris Albertson
For example your computer
makes step and direction pulses but a bipolar stepping motor wants to see
voltages on it's four lead wires. Why not have the computer computer the
voltages?
To answer just one point, the main thing that the stepper driver does
is actively control the current through the motor.
LinuxCNC can already drive unipolar steppers directly, but only at tiny powers.
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
Przemek Klosowski
2017-05-04 14:34:15 UTC
Permalink
Just to further confuse the matters, here's another ARM board: it's a
BeagleBone version specially designed for robotics/machine control:

http://makezine.com/product-review/beaglebone-blue/?utm_source=facebook&utm_medium=social&utm_campaign=digikey&utm_term=boards%20guide&utm_content=beaglebone%20blue
Post by Gene Heskett
Greetings;
What x86 board, suitably small but not that outpriced yudoo thingy, will
run linuxcnc well AND can do the spi thing?
Cheers, Gene Heskett
--
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
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Gene Heskett
2017-05-04 16:44:32 UTC
Permalink
Post by Przemek Klosowski
Just to further confuse the matters, here's another ARM board: it's a
http://makezine.com/product-review/beaglebone-blue/?utm_source=faceboo
k&utm_medium=social&utm_campaign=digikey&utm_term=boards%20guide&utm_co
ntent=beaglebone%20blue
If I was starting from scratch, maybe. But I've now 6 months invested in
the pi, and I've written a heck of a lot of code.

So I don't want to start from scratch again. I may not have the time to
finish it left.
Post by Przemek Klosowski
Post by Gene Heskett
Greetings;
What x86 board, suitably small but not that outpriced yudoo thingy,
will run linuxcnc well AND can do the spi thing?
Cheers, Gene Heskett
--
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
https://lists.sourceforge.net/lists/listinfo/emc-users
----------------------------------------------------------------------
-------- 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
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>
Charles Steinkuehler
2017-05-04 20:25:00 UTC
Permalink
Post by Gene Heskett
Post by Przemek Klosowski
Just to further confuse the matters, here's another ARM board: it's a
http://makezine.com/product-review/beaglebone-blue/?utm_source=faceboo
k&utm_medium=social&utm_campaign=digikey&utm_term=boards%20guide&utm_co
ntent=beaglebone%20blue
If I was starting from scratch, maybe. But I've now 6 months invested in
the pi, and I've written a heck of a lot of code.
Out of curiosity, are you building from source or is there a package
repo for LinuxCNC on the RPi?

I have someone interested in using a RPi+Mesa instead of a BBB for a
small machine control. We're not actively building Machinekit
packages for Raspbian, and I noticed the LCNC hostmot2 driver has a
RPi SPI driver. Is that what you're using? I don't want to point him
this direction if it's not particularly stable, but he's technically
savvy enough to get over a few rough spots.
--
Charles Steinkuehler
***@steinkuehler.net
Sebastian Kuzminsky
2017-05-04 20:58:54 UTC
Permalink
Post by Charles Steinkuehler
Post by Gene Heskett
Post by Przemek Klosowski
Just to further confuse the matters, here's another ARM board: it's a
http://makezine.com/product-review/beaglebone-blue/?utm_source=faceboo
k&utm_medium=social&utm_campaign=digikey&utm_term=boards%20guide&utm_co
ntent=beaglebone%20blue
If I was starting from scratch, maybe. But I've now 6 months invested in
the pi, and I've written a heck of a lot of code.
Out of curiosity, are you building from source or is there a package
repo for LinuxCNC on the RPi?
I have someone interested in using a RPi+Mesa instead of a BBB for a
small machine control. We're not actively building Machinekit
packages for Raspbian, and I noticed the LCNC hostmot2 driver has a
RPi SPI driver. Is that what you're using? I don't want to point him
this direction if it's not particularly stable, but he's technically
savvy enough to get over a few rough spots.
We don't build Raspbian packages. We do build Debian Wheezy packages
for armhf, but my understanding is those won't work on a Raspberry Pi.
--
Sebastian Kuzminsky
Gene Heskett
2017-05-05 01:16:38 UTC
Permalink
Post by Charles Steinkuehler
Post by Gene Heskett
Post by Przemek Klosowski
Just to further confuse the matters, here's another ARM board: it's
a BeagleBone version specially designed for robotics/machine
http://makezine.com/product-review/beaglebone-blue/?utm_source=face
boo
k&utm_medium=social&utm_campaign=digikey&utm_term=boards%20guide&ut
m_co ntent=beaglebone%20blue
If I was starting from scratch, maybe. But I've now 6 months
invested in the pi, and I've written a heck of a lot of code.
Out of curiosity, are you building from source or is there a package
repo for LinuxCNC on the RPi?
Charles;

Its actually running the 2.8pre x86 code, for master-sim, straight out of
the buildbot at <http://buildbot.linuxcnc.org jessie master-sim>.

Sim in this case only seems to mean its not running any cpu burning PID
modules. And doesn't appear to suffer because of the lack of PID's on a
stepper system. With servo's I'd expect to need the PID's. Other than
that, the ini, hal, xml and assorted txt files should be able to run on
an x86 box if I mailed them to you. Correcting the i/o wiring, or the
hal bits that assign a signal to such and such a pin to match up with
what you've got built already would be the major reason to edit the hal
files.
Post by Charles Steinkuehler
I have someone interested in using a RPi+Mesa instead of a BBB for a
small machine control. We're not actively building Machinekit
packages for Raspbian, and I noticed the LCNC hostmot2 driver has a
RPi SPI driver. Is that what you're using?
yes, hm2-rpspi.ko, which is loaded by the hm2-7i90.ko card driver.
Post by Charles Steinkuehler
I don't want to point him
this direction if it's not particularly stable, but he's technically
savvy enough to get over a few rough spots.
Since I'm walking on new ground with this, Martinjack seems to have
disappeared, its a somewhat lonely trail. I could use the company as I
toddle along.

Its just as stable as the same code running on an x86 box would be.

The only warning I'd issue other than keeping motorish noises out of the
system with a single point ground system, is the whole i/o on a pi comes
and goes thru whats basically a usb hub, and keyboard/mouse events seem
to be treated with very poor priority as the uptime accumulates.

Generally fixed for a while by rebooting. That needs addressed by the pi
builders, probably by adding enough memory that it stays out of the swap
file. It has a gig now, needs another from my diagnosis.

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>
TJoseph Powderly
2017-05-05 03:56:15 UTC
Permalink
hi gene
Post by Gene Heskett
Charles;
Its actually running the 2.8pre x86 code, for master-sim, straight out of
the buildbot at <http://buildbot.linuxcnc.org jessie master-sim>.
? raspberry pi runs x86 code?
also
the url might be better as

<http://buildbot.linuxcnc.org> please look for "jessie master-sim"

or describe it as an entry to sources.list
Post by Gene Heskett
Sim in this case only seems to mean its not running any cpu burning PID
modules.
did you actually use
http://buildbot.linuxcnc.org/dists/jessie/2.7-sim/binary-armhf/linuxcnc-uspace-dev_2.7.8.16.ga380981_armhf.deb
<http://buildbot.linuxcnc.org/dists/jessie/2.7-sim/binary-armhf/linuxcnc-uspace-dev_2.7.8.16.ga380981_armhf.deb>
or a similar armhf version?
Post by Gene Heskett
And doesn't appear to suffer because of the lack of PID's on a
stepper system.
so you used a sim but got it to drive hardware?
the spi module talked to the 7i90 using a sim linuxcnc?
Post by Gene Heskett
With servo's I'd expect to need the PID's. Other than
that, the ini, hal, xml and assorted txt files should be able to run on
an x86 box if I mailed them to you. Correcting the i/o wiring, or the
hal bits that assign a signal to such and such a pin to match up with
what you've got built already would be the major reason to edit the hal
files.
Post by Charles Steinkuehler
I have someone interested in using a RPi+Mesa instead of a BBB for a
small machine control. We're not actively building Machinekit
packages for Raspbian, and I noticed the LCNC hostmot2 driver has a
RPi SPI driver. Is that what you're using?
yes, hm2-rpspi.ko, which is loaded by the hm2-7i90.ko card driver.
Post by Charles Steinkuehler
I don't want to point him
this direction if it's not particularly stable, but he's technically
savvy enough to get over a few rough spots.
Since I'm walking on new ground with this, Martinjack seems to have
disappeared, its a somewhat lonely trail. I could use the company as I
toddle along.
Its just as stable as the same code running on an x86 box would be.
The only warning I'd issue other than keeping motorish noises out of the
system with a single point ground system, is the whole i/o on a pi comes
and goes thru whats basically a usb hub, and keyboard/mouse events seem
to be treated with very poor priority as the uptime accumulates.
Generally fixed for a while by rebooting. That needs addressed by the pi
builders, probably by adding enough memory that it stays out of the swap
file. It has a gig now, needs another from my diagnosis.
Cheers, Gene Heskett
thanks gene,

i may look again at the OPI+2e which runs video smooth with recent (
april2017) debian xfce4

apparently some tricks can be pulled using DietPi to make it more
lightweight and hopefully les latent.

tomp tjtr33
Charles Steinkuehler
2017-05-05 12:41:59 UTC
Permalink
Post by Gene Heskett
Post by Charles Steinkuehler
Out of curiosity, are you building from source or is there a package
repo for LinuxCNC on the RPi?
Charles;
Its actually running the 2.8pre x86 code, for master-sim, straight out of
the buildbot at <http://buildbot.linuxcnc.org jessie master-sim>.
So does the armhf build run in Raspian or are you using qemu or
something? AFAIK, standard Debian armhf code won't run on the RPi
because Raspbian uses a different ABI (due to the not-quite full armhf
compatible CPU on the original RPi).

...but with Jessie you could maybe run multiarch and get the official
armhf libraries running alongside the Raspbian ones?
Post by Gene Heskett
Post by Charles Steinkuehler
I don't want to point him
this direction if it's not particularly stable, but he's technically
savvy enough to get over a few rough spots.
Since I'm walking on new ground with this, Martinjack seems to have
disappeared, its a somewhat lonely trail. I could use the company as I
toddle along.
Its just as stable as the same code running on an x86 box would be.
The only warning I'd issue other than keeping motorish noises out of the
system with a single point ground system, is the whole i/o on a pi comes
and goes thru whats basically a usb hub, and keyboard/mouse events seem
to be treated with very poor priority as the uptime accumulates.
Generally fixed for a while by rebooting. That needs addressed by the pi
builders, probably by adding enough memory that it stays out of the swap
file. It has a gig now, needs another from my diagnosis.
I installed Raspbian and see what you mean about the delays. It
doesn't look like it's swapping, more like there's something that's
single-threaded and ends up blocking most of the system for a while.

I haven't dug into it deeply, but it seems like it's probably the uSD
driver. Also, uSD access speeds are *SLOW* (at least perceptively, I
don't have actual speed tests yet). With a 16G Class-10 uSD it was
taking _forever_ to install the build deps on the RPi3, something I've
done many times (and which goes much faster) on the BBB using
identical uSD cards.
--
Charles Steinkuehler
***@steinkuehler.net
andy pugh
2017-05-05 12:56:27 UTC
Permalink
Post by Charles Steinkuehler
So does the armhf build run in Raspian or are you using qemu or
something? AFAIK, standard Debian armhf code won't run on the RPi
because Raspbian uses a different ABI (due to the not-quite full armhf
compatible CPU on the original RPi).
It might be worth considering that Gene's experience seems to be that
LinuxCNC on the Pi runs less than flawlessly.

https://wiki.debian.org/RaspberryPi

Seems to suggest that armhf works on Pi >= 2.0

buildbot "sim" builds run with realtime on preempt-rt kernels.
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916
dragon
2017-05-05 13:23:45 UTC
Permalink
From my understanding, a straight Debian armhf distro install will run
on the rPi 2 and rPi 3. It should also provide performance improvements
over Raspbian. When Raspbian is built there are many compiler flags that
are disabled for things like vector instructions, etc. This is for
backward compatibility with the first generation of the rPi which has a
much older and stripped down ARM core.

I have no idea if packages compiled for use on an armhf Debian
environment would run on Raspbian, but my guess is that there would be
issues in addition to poor performance depending on the package.

I was looking at using the rPi 2/3 for some realtime audio stuff and
moving to a full fledged armhf distro with the ARM equivalent of SIMD
(vector) instructions enabled made a HUGE difference in what could be
accomplished. I found that Raspbian really hamstrung the performance of
the newer boards and moving to a full fledged armhf distro was like a
night and day performance difference. It went from "this won't work" to
"wow, what else can I throw at this thing!" This was quite some time ago
so perhaps Raspbian has improved? That project got put aside due to
other priorities :(
Post by andy pugh
Post by Charles Steinkuehler
So does the armhf build run in Raspian or are you using qemu or
something? AFAIK, standard Debian armhf code won't run on the RPi
because Raspbian uses a different ABI (due to the not-quite full armhf
compatible CPU on the original RPi).
It might be worth considering that Gene's experience seems to be that
LinuxCNC on the Pi runs less than flawlessly.
https://wiki.debian.org/RaspberryPi
Seems to suggest that armhf works on Pi >= 2.0
buildbot "sim" builds run with realtime on preempt-rt kernels.
Charles Steinkuehler
2017-05-05 13:25:01 UTC
Permalink
Post by andy pugh
Post by Charles Steinkuehler
So does the armhf build run in Raspian or are you using qemu or
something? AFAIK, standard Debian armhf code won't run on the RPi
because Raspbian uses a different ABI (due to the not-quite full armhf
compatible CPU on the original RPi).
It might be worth considering that Gene's experience seems to be that
LinuxCNC on the Pi runs less than flawlessly.
Indeed. I've only just started playing with the RPi3 and have already
hit some issues. I was hoping the GPU would be usable, but it looks
like there are still problems. I think the BBB (or an SoC+FPGA) is
probably a better choice if you don't need a native GUI, and if you
_do_ want a GUI a low-end x86 box is likely a much better choice.

I've ordered one of these x86 SBCs to play with and see if I can get
it talking to Mesa hardware via SPI:

http://up-shop.org/up-boards/2-up-board-2gb-16-gb-emmc-memory.html

...if it works out, it may be a good midway point between the ARM
based SBCs and a full x86 machine.
Post by andy pugh
https://wiki.debian.org/RaspberryPi
Seems to suggest that armhf works on Pi >= 2.0
buildbot "sim" builds run with realtime on preempt-rt kernels.
Yeah, I should be able to use the armhf builds if I'm running stock
Debian (which works on the RPi 2 & 3). I started with Raspbian to see
what the "out-of-the-box" experience is like, and figure it's unlikely
I can tweak Debian to work better than Raspbian. I'm unclear what
Gene's running, but I'm guessing it's Debian armhf rather than Raspbian.
--
Charles Steinkuehler
***@steinkuehler.net
Gene Heskett
2017-05-05 21:34:57 UTC
Permalink
Post by Charles Steinkuehler
On 5 May 2017 at 13:41, Charles Steinkuehler
Post by Charles Steinkuehler
So does the armhf build run in Raspian or are you using qemu or
something? AFAIK, standard Debian armhf code won't run on the RPi
because Raspbian uses a different ABI (due to the not-quite full
armhf compatible CPU on the original RPi).
It might be worth considering that Gene's experience seems to be
that LinuxCNC on the Pi runs less than flawlessly.
Indeed. I've only just started playing with the RPi3 and have already
hit some issues. I was hoping the GPU would be usable, but it looks
like there are still problems. I think the BBB (or an SoC+FPGA) is
probably a better choice if you don't need a native GUI, and if you
_do_ want a GUI a low-end x86 box is likely a much better choice.
I've ordered one of these x86 SBCs to play with and see if I can get
http://up-shop.org/up-boards/2-up-board-2gb-16-gb-emmc-memory.html
...if it works out, it may be a good midway point between the ARM
based SBCs and a full x86 machine.
https://wiki.debian.org/RaspberryPi
Seems to suggest that armhf works on Pi >= 2.0
buildbot "sim" builds run with realtime on preempt-rt kernels.
Yeah, I should be able to use the armhf builds if I'm running stock
Debian (which works on the RPi 2 & 3). I started with Raspbian to see
what the "out-of-the-box" experience is like, and figure it's unlikely
I can tweak Debian to work better than Raspbian. I'm unclear what
Gene's running, but I'm guessing it's Debian armhf rather than
Raspbian.
Nope, raspian. From my /etc/apt/sources.list:

deb http://mirrordirector.raspbian.org/raspbian/ jessie main contrib
non-free rpi
# Uncomment line below then 'apt-get update' to enable 'apt-get source'
#deb-src http://archive.raspbian.org/raspbian/ jessie main contrib
non-free rpi
deb http://buildbot.linuxcnc.org/ jessie master-sim
deb-src http://buildbot.linuxcnc.org/ jessie master-sim

no debian in site other than whats been thru the raspian "filter".

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>
Gene Heskett
2017-05-05 21:43:16 UTC
Permalink
Post by Charles Steinkuehler
On 5 May 2017 at 13:41, Charles Steinkuehler
Post by Charles Steinkuehler
So does the armhf build run in Raspian or are you using qemu or
something? AFAIK, standard Debian armhf code won't run on the RPi
because Raspbian uses a different ABI (due to the not-quite full
armhf compatible CPU on the original RPi).
It might be worth considering that Gene's experience seems to be
that LinuxCNC on the Pi runs less than flawlessly.
Indeed. I've only just started playing with the RPi3 and have already
hit some issues. I was hoping the GPU would be usable, but it looks
like there are still problems. I think the BBB (or an SoC+FPGA) is
probably a better choice if you don't need a native GUI, and if you
_do_ want a GUI a low-end x86 box is likely a much better choice.
I've ordered one of these x86 SBCs to play with and see if I can get
http://up-shop.org/up-boards/2-up-board-2gb-16-gb-emmc-memory.html
That looks like a raspi killer, but whats an eMMC memory, because I sure
don't see a socket for a micro-sd card.
Post by Charles Steinkuehler
...if it works out, it may be a good midway point between the ARM
based SBCs and a full x86 machine.
I agree, except for the system memory.

Soldered to the board flash memory bothers me, a lot. If it didn't, I
would have used my card to put some postage on its even better equipt
4Gb dram and 32Gb of e-MMC. I have 2 of the original D525MW boards, one
of them is still software stepping a 4 axis micro-mill. Not fast, but
fast enough to get the job done.
Post by Charles Steinkuehler
https://wiki.debian.org/RaspberryPi
Seems to suggest that armhf works on Pi >= 2.0
buildbot "sim" builds run with realtime on preempt-rt kernels.
Yeah, I should be able to use the armhf builds if I'm running stock
Debian (which works on the RPi 2 & 3). I started with Raspbian to see
what the "out-of-the-box" experience is like, and figure it's unlikely
I can tweak Debian to work better than Raspbian. I'm unclear what
Gene's running, but I'm guessing it's Debian armhf rather than
Raspbian.
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>
Charles Steinkuehler
2017-05-05 21:57:51 UTC
Permalink
Post by Gene Heskett
Post by Charles Steinkuehler
I've ordered one of these x86 SBCs to play with and see if I can get
http://up-shop.org/up-boards/2-up-board-2gb-16-gb-emmc-memory.html
That looks like a raspi killer, but whats an eMMC memory, because I sure
don't see a socket for a micro-sd card.
eMMC is the flash memory used in just about anything that has a decent
amount of in-device storage but doesn't use a SATA style HDD (think
cell-phones, iPads, tablets, etc).

...probably not a raspi killer at ~ $100, but given the state of the
GPU on the Pi (and most other ARM SBCs) it may make a good platform
for anything that needs a GPU with decent support for anything other
than Android.
Post by Gene Heskett
Post by Charles Steinkuehler
...if it works out, it may be a good midway point between the ARM
based SBCs and a full x86 machine.
I agree, except for the system memory.
Soldered to the board flash memory bothers me, a lot. If it didn't, I
would have used my card to put some postage on its even better equipt
4Gb dram and 32Gb of e-MMC. I have 2 of the original D525MW boards, one
of them is still software stepping a 4 axis micro-mill. Not fast, but
fast enough to get the job done.
They have versions with more memory (both DRAM and flash), and the "UP
Squared" has a SATA port and mPCI-e if you want to hook up "real" storage.

I got the next-to-cheapest version (2G instead of 1G DRAM) just to
play around with. If it turns out to be viable but needs a bit more
"oompf", there are options available.

Interestingly, they show the "Squared" shipping in July, and the "UP"
shipping in 7 days, but I got emails (from both UP and FedEx) saying
my UP board shipped less than a day after placing the order. And the
Mesa 7i90 arrived today, so I've got lots of new toys to play with! :)
--
Charles Steinkuehler
***@steinkuehler.net
Gregg Eshelman
2017-05-05 23:54:16 UTC
Permalink
I'd like to see someone buy the Rendition Verite intellectual property from Micron, then make the design open, with a very small royalty fee per chip. A few cents each, at least until the cost to buy it is recovered.
The Verite 2200 could be given a major die shrink by transitioning it to the latest, smallest process and used as a discreet GPU or integrated into a SOC. The shrink could ramp up its performance by enabling a drastic power use reduction and clock speed increase.
With an open design, manufacturers would be able to enhance the GPU, as long as they contributed back to the source. The entire programming interface and additions would also have to be open. Verite could become a GPU to challenge all the other GPUs being used for systems that aren't "PC" or Macintosh. The other companies would either have to open up their programming information to make it easier to write drivers or they'd find themselves in the position Rendition ended up in.

Rendition was neck and neck in GPU performance with 3Dfx, ATi and nVidia, all of which were crushing the other competitors. The Verite 1000 was as good or better than the other contemporary GPUs.
Then they hit a big pothole. Rendition had bought some silicon design elements to incorporate into the next generation V2100 and V2200. (The only difference was clock speed, only one card ever used the V2100 and a video BIOS update clocked it up to V2200 speed.) It took them six months of troubleshooting and going over the sample chips with an electron microscope to find the flaw. In that time, ATi and nVidia had leapt ahead another design generation, 3Dfx was floundering and companies like S3, Cirrus Logic, Number Nine, Trident, and a dozen or two others were out of business completely or about to be, bought by ATi or nVidia (or about to be) or quit making video chips to focus on other products.

Micron bought Rendition and even hired most of the people. Made announcements that they would continue to develop products (Rendition was working on a couple of successors to the V2200 but didn't have the $$$$.) Micron even promised to finish the work on a full OpenGL ICD for the V1000. None of that ever happened. Within a year Rendition was dead and buried, existing only as a sub-brand name for a line of mid-range price Micron computer RAM.
I'd think Micron would at least want to be able to say to their shareholders "Well, we finally got the money back on buying Rendition." (Nevermind about inflation, the number's the same in the bookkeeping.)
To sweeten the deal, the Open Verite GPU could be adapted to work tightly with some fast Micron RAM, perhaps even integrating with a bunch of RAM in the same package. A tiny, fast, low power GPU packed with a gig of fast Micron RAM could find a lot of uses, even in desktop and laptop PCs but especially in mobile devices with high resolution displays. The GPU section of the die could be open design while keeping the RAM parts proprietary - especially if designed so the interface between them is a straight line so if needed the RAM could be cut off to package the GPU alone.
On Friday, May 5, 2017, 4:02:03 PM MDT, Charles Steinkuehler <***@steinkuehler.net> wrote:
eMMC is the flash memory used in just about anything that has a decent
amount of in-device storage but doesn't use a SATA style HDD (think
cell-phones, iPads, tablets, etc).

...probably not a raspi killer at ~ $100, but given the state of the
GPU on the Pi (and most other ARM SBCs) it may make a good platform
for anything that needs a GPU with decent support for anything other
than Android.
Gene Heskett
2017-05-07 19:32:07 UTC
Permalink
Post by Gene Heskett
Post by Charles Steinkuehler
On 5 May 2017 at 13:41, Charles Steinkuehler
Post by Charles Steinkuehler
So does the armhf build run in Raspian or are you using qemu or
something? AFAIK, standard Debian armhf code won't run on the
RPi because Raspbian uses a different ABI (due to the not-quite
full armhf compatible CPU on the original RPi).
It might be worth considering that Gene's experience seems to be
that LinuxCNC on the Pi runs less than flawlessly.
Indeed. I've only just started playing with the RPi3 and have
already hit some issues. I was hoping the GPU would be usable, but
it looks like there are still problems. I think the BBB (or an
SoC+FPGA) is probably a better choice if you don't need a native
GUI, and if you _do_ want a GUI a low-end x86 box is likely a much
better choice.
I've ordered one of these x86 SBCs to play with and see if I can get
http://up-shop.org/up-boards/2-up-board-2gb-16-gb-emmc-memory.html
That looks like a raspi killer, but whats an eMMC memory, because I
sure don't see a socket for a micro-sd card.
Post by Charles Steinkuehler
...if it works out, it may be a good midway point between the ARM
based SBCs and a full x86 machine.
I agree, except for the system memory.
Soldered to the board flash memory bothers me, a lot. If it didn't, I
would have used my card to put some postage on its even better equipt
4Gb dram and 32Gb of e-MMC. I have 2 of the original D525MW boards,
one of them is still software stepping a 4 axis micro-mill. Not fast,
but fast enough to get the job done.
Post by Charles Steinkuehler
https://wiki.debian.org/RaspberryPi
Seems to suggest that armhf works on Pi >= 2.0
buildbot "sim" builds run with realtime on preempt-rt kernels.
Unfortunately, the buildbot has been unreachable since my problems began.
I have stripped my sources.lists down to just the buildbot:
deb http://buildbot.linuxcnc.org/ jessie master-sim
deb-src http://buildbot.linuxcnc.org/ jessie master-sim

but sudo apt update returns:

Err http://buildbot.linuxcnc.org jessie InRelease

Err http://buildbot.linuxcnc.org jessie Release.gpg
Could not resolve 'buildbot.linuxcnc.org'
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
W: Failed to fetch http://buildbot.linuxcnc.org/dists/jessie/InRelease

W: Failed to fetch http://buildbot.linuxcnc.org/dists/jessie/Release.gpg
Could not resolve 'buildbot.linuxcnc.org'

W: Some index files failed to download. They have been ignored, or old
ones used instead.

The web page is there at buildbot from this machine, but Damn if
network-mangler hasn't re-written the /etc/resolv.conf with a blank
file. First is nuke resolvconf, rewrite a good /etc/resolv.conf, make
sure it works and sudo chattr +i /etc/resolv.conf. Done. Now the
buildbot responds and tells me linuxcnc is all up to date.
Post by Gene Heskett
Post by Charles Steinkuehler
Yeah, I should be able to use the armhf builds if I'm running stock
Debian (which works on the RPi 2 & 3). I started with Raspbian to
see what the "out-of-the-box" experience is like, and figure it's
unlikely I can tweak Debian to work better than Raspbian. I'm
unclear what Gene's running, but I'm guessing it's Debian armhf
rather than Raspbian.
Cheers, Gene Heskett
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>
Gene Heskett
2017-05-05 21:15:10 UTC
Permalink
Post by Charles Steinkuehler
Post by Gene Heskett
Post by Charles Steinkuehler
Out of curiosity, are you building from source or is there a
package repo for LinuxCNC on the RPi?
Charles;
Its actually running the 2.8pre x86 code, for master-sim, straight
out of the buildbot at <http://buildbot.linuxcnc.org jessie
master-sim>.
So does the armhf build run in Raspian or are you using qemu or
something? AFAIK, standard Debian armhf code won't run on the RPi
because Raspbian uses a different ABI (due to the not-quite full armhf
compatible CPU on the original RPi).
Runs on raspian. here is /etc/issue
Raspbian GNU/Linux 8 \n \l
Post by Charles Steinkuehler
...but with Jessie you could maybe run multiarch and get the official
armhf libraries running alongside the Raspbian ones?
No clue. Until an update over this past weekend, it just ran, but much of
the /boot partition was updated, and now it will not boot at all.

So I'm running on a re-install of
raspi3-linuxcnc-hm2-rpspi-8GB.img

Which I got from one of the developers as a .gz. I can make it available
on my web page, but its 6Gb and small change so the transfer will take a
while. Done, its in the opt/lathe-stf subdir of my web page.

Put this image on a 16 or 32Gb u-sd card, then put the card in the pi and
power it up. If it doesn't run raspi-config on bootup, open an
LXterminal, and
sudo raspi-config
one of the first options is to expand the filesystems 2nd partition to
take advantage of the whole card, choose that and have it do it.

I also, while the LXTerminal is handy, change user pi's passwd to match
yours so you don't have yet another password to remember.

Then, because synaptic, when you install it, is locked down to root, and
a sudo doesn't work, do a
sudo passwd
and set yourself a big long root password, but one you can remember. And
just in case your wet ram is as old as mine, put a dymo label next to
the pi with it on it.

If the video doesn't fit the screen:
sudo nano /boot/config.txt
find the framebuffer size options and comment them out, hit ctl+o,return
then ctl+x to exit nano. reboot for effect.

EDID does work, but you might have to ascertain the monitors h & v size,
go back into /boot/config.txt, uncomment those 2 framebuffer size lines
and enter the proper sizes for your monitor. I am using HDMI cabling
straight thru, but its my impression some hdmi->vga adapters will garble
that EDID feedback.
Post by Charles Steinkuehler
Post by Gene Heskett
Post by Charles Steinkuehler
I don't want to point him
this direction if it's not particularly stable, but he's
technically savvy enough to get over a few rough spots.
Since I'm walking on new ground with this, Martinjack seems to have
disappeared, its a somewhat lonely trail. I could use the company
as I toddle along.
Its just as stable as the same code running on an x86 box would be.
The only warning I'd issue other than keeping motorish noises out of
the system with a single point ground system, is the whole i/o on a
pi comes and goes thru whats basically a usb hub, and keyboard/mouse
events seem to be treated with very poor priority as the uptime
accumulates.
Generally fixed for a while by rebooting. That needs addressed by
the pi builders, probably by adding enough memory that it stays out
of the swap file. It has a gig now, needs another from my
diagnosis.
I installed Raspbian and see what you mean about the delays. It
doesn't look like it's swapping, more like there's something that's
single-threaded and ends up blocking most of the system for a while.
I haven't dug into it deeply, but it seems like it's probably the uSD
driver. Also, uSD access speeds are *SLOW* (at least perceptively, I
don't have actual speed tests yet). With a 16G Class-10 uSD it was
taking _forever_ to install the build deps on the RPi3, something I've
done many times (and which goes much faster) on the BBB using
identical uSD cards.
Good luck.

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>
Nicklas Karlsson
2017-05-04 18:44:08 UTC
Permalink
A good device indeed it seems to be.

On Thu, 4 May 2017 10:34:15 -0400
Post by Przemek Klosowski
Just to further confuse the matters, here's another ARM board: it's a
http://makezine.com/product-review/beaglebone-blue/?utm_source=facebook&utm_medium=social&utm_campaign=digikey&utm_term=boards%20guide&utm_content=beaglebone%20blue
Post by Gene Heskett
Greetings;
What x86 board, suitably small but not that outpriced yudoo thingy, will
run linuxcnc well AND can do the spi thing?
Cheers, Gene Heskett
--
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
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