#linuxcnc-devel | Logs for 2015-06-01

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[06:40:34] <jthornton> mozmck, http://gnipsel.com/shop/plasma/files/touchoff.ngc
[06:50:47] <skunkworks> zlog
[08:51:14] <archivist> a real cnc on a chip real soon? http://www.businesswire.com/news/home/20150601005864/en/Intel-Acquire-Altera#.VWxaJc9Qeac
[09:41:34] <pcw_home> Intel manufactured Altera parts a looong time ago
[09:42:10] <pcw_home> (we used their EP900 PLDs for a while)
[09:49:37] <pcw_home> You could also just as well use a Zynq chip if you want CPU and
[09:49:38] <pcw_home> FPGA on the same chip (and dont needs lots of CPU horsepower)
[09:49:40] <pcw_home> (or just TI ARM with PRU like BBB)
[09:57:46] <CaptHindsight> there we two FPGA cards released recently that plug into the BBB or the RPi, both Altera
[09:58:26] <CaptHindsight> pcw_home: did you see the latency with preempt_rt of the ZYNQ?
[09:58:50] <pcw_home> Not recently
[10:00:10] <CaptHindsight> this looks better http://www.wiki.xilinx.com/Zynq-7000+AP+SoC+-+RealTime+-+InterruptLatency+Reference+Design+and+Demo+Tech+Tip
[10:00:56] <CaptHindsight> the Zedboard tests were >50uS
[10:01:44] <pcw_home> Now that we can retime the position sampling even 300-400 usec latency is acceptable so its not a really big concern
[10:03:38] <pcw_home> (and interrupt latency is rather meaningless for linuxcnc)
[10:16:41] <pcw_home> (at least for servo thread only systems)
[10:18:10] <skunkworks> is this a lot of jitter?
[10:18:12] <skunkworks> http://electronicsam.com/images/KandT/testing/grbl/linuxcncdither.png
[10:19:27] <skunkworks> I just noticed that the velocity in linuxcnc was peaking at 8.8 or more in/sec... (set for 8.3) and it was peaking around that. (software stepgen at 30in/s^2 with a stepgen headroom of 34in/s^2
[10:22:31] <pcw_home> probably dither from beat between basethread rate and step rate
[10:23:27] <pcw_home> with some sampling aliasing added to the mix :-)
[10:28:36] <skunkworks> I suppose every few ms of jitter probably isn't going to effect motion
[10:31:26] <skunkworks> it averages out
[10:31:44] <pcw_home> It has some effect on step motor systems. People have been able to get
[10:31:46] <pcw_home> substatially higher rapid speeds with hardware stepgens even if the software
[10:31:47] <pcw_home> stepgen could generate the required step rate. I suspect it has somethin to do
[10:31:49] <pcw_home> with beat frequencies causing resonances at higher speeds when step motor systems
[10:31:50] <pcw_home> have little margin left
[10:32:04] <skunkworks> sure
[10:33:11] <pcw_home> in general though its probably not too important
[10:35:24] <pcw_home> might be interesting to run the software stepgen output ( at various constant speeds) through a spectrum anaylser
[10:46:04] <pcw_home> That is if you generate a 10.5 KHz step rate from a 50 KHz base thread you will have substantial energy at 500 Hz
[10:46:05] <pcw_home> (in the range of step motor resonances )
[13:04:20] <skunkworks> sounds like a movie plot!
[13:19:59] <ssi> right up there with "a monad is a monoid in the category of endofunctors" ?
[13:23:03] <pcw_home> Is that a funk group?
[13:23:56] <cradek> newgrass
[13:27:20] <ssi> MATHROCK
[13:48:19] <skunkworks> punkfolk?
[13:57:16] <skunkworks> http://www.cnczone.com/forums/opensource-software/271966-grbl-logging-linuxcnc.html#post1710758
[17:11:56] <cradek> skunkworks: mach gives you accel of 139 when you set it for max 30?
[20:18:18] <mozmck> Is EMC2_HOME used as an environment variable any more?
[20:20:45] <Tom_itx> what did it do?
[20:20:46] <KGB-linuxcnc> 03Moses McKnight 052.7 baa2891 06linuxcnc 10lib/python/gladevcp/hal_sourceview.py EMC_Sourceview.set_language() was broken if no path passed in. * 14http://git.linuxcnc.org/?p=linuxcnc.git;a=commitdiff;h=baa2891
[20:21:09] <Tom_itx> there are HOME_ vars but i don't think that's one of them
[20:21:23] <mozmck> I assume it contained the base path for linuxcnc, and may be used for RIP
[20:21:34] <Tom_itx> there is HOME by itself
[20:21:54] <Tom_itx> i'm looking in axis sections
[20:22:43] <mozmck> Ah, yes, it's still set in the rip-environment script.
[21:09:27] <linuxcnc-build> build #3172 of 0000.checkin is complete: Failure [4failed] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/0000.checkin/builds/3172 blamelist: Moses McKnight <moses@texband.net>
[22:10:08] <linuxcnc-build> build #578 of 4015.deb-wheezy-rtpreempt-amd64 is complete: Failure [4failed apt-get-update shell_1] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/4015.deb-wheezy-rtpreempt-amd64/builds/578 blamelist: Moses McKnight <moses@texband.net>
[22:13:04] <linuxcnc-build> build #539 of 4014.deb-wheezy-rtpreempt-i386 is complete: Failure [4failed apt-get-update shell_1] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/4014.deb-wheezy-rtpreempt-i386/builds/539 blamelist: Moses McKnight <moses@texband.net>
[22:41:44] <linuxcnc-build> build #983 of 1401.rip-wheezy-rtai-i386 is complete: Failure [4failed apt-get-update compile runtests] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/1401.rip-wheezy-rtai-i386/builds/983 blamelist: Moses McKnight <moses@texband.net>
[23:29:23] <linuxcnc-build> build #1321 of 1403.rip-wheezy-amd64 is complete: Failure [4failed garbage-collect git repo] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/1403.rip-wheezy-amd64/builds/1321 blamelist: Moses McKnight <moses@texband.net>
[23:29:24] <linuxcnc-build> build #3173 of 0000.checkin is complete: Failure [4failed] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/0000.checkin/builds/3173 blamelist: Moses McKnight <moses@texband.net>
[23:50:44] <linuxcnc-build> build #1512 of 1404.rip-wheezy-rtpreempt-amd64 is complete: Failure [4failed garbage-collect git repo] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/1404.rip-wheezy-rtpreempt-amd64/builds/1512 blamelist: Moses McKnight <moses@texband.net>
[23:50:46] <linuxcnc-build> build #1321 of 1400.rip-wheezy-i386 is complete: Failure [4failed garbage-collect git repo] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/1400.rip-wheezy-i386/builds/1321 blamelist: Moses McKnight <moses@texband.net>
[23:50:52] <linuxcnc-build> build #1322 of 1403.rip-wheezy-amd64 is complete: Failure [4failed garbage-collect git repo] Build details are at http://buildbot.linuxcnc.org/buildbot/builders/1403.rip-wheezy-amd64/builds/1322 blamelist: Moses McKnight <moses@texband.net>