#linuxcnc Logs

Sep 21 2020

#linuxcnc Calendar

01:03 AM Deejay: moin
02:09 AM CaptHindsight: Rpi4 2.8 sdcard img gives me 130,000 on the latency test when a video is played in Chrome
02:09 AM CaptHindsight: overclocked to 2.1Ghz, isolcpus=1,2,3, idle=poll
02:09 AM CaptHindsight: overclocked to 2.1Ghz, isolcpus=3, idle=poll was >300,000
02:15 AM CaptHindsight: are there some magic kernel config lines I'm missing to get the reported 70,000 max?
02:15 AM CaptHindsight: it's running the rt kernel from the .img
03:04 AM CaptHindsight: this is with base threads of 50,000, 75,000, 100,000 and even 200,000
03:26 AM CaptHindsight: similar numbers with only a 100,000 servo thread, no base
03:27 AM CaptHindsight: what did really drop the latency was killing GPU acceleration, but then no 4K video
03:32 AM alexfloca: hello everybody, i have written a short python code to read from the serial line and update an analogic hal pin. the problem is everything works fine until i enable the axis, as soon as the axis are enabled i loose characters received over the serial line.
03:32 AM alexfloca: could anyone guide me to where i could find more information on timing of python codes
03:32 AM alexfloca: ?
03:34 AM rs[m]: CaptHindsight: don't overclock, keep the SOC cool
03:40 AM CaptHindsight: rs[m]: I'm keeping it cool
03:40 AM CaptHindsight: it's a non-issue here
03:52 AM CaptHindsight: turned off GPU accel and video4linux and with 100,000 servo thread latency stayed <30,000 until we started the browser then it jumped to ~50K, then to 102,000 after 10 minutes of playing a video
03:52 AM CaptHindsight: software rendering at 1920x1080
03:54 AM CaptHindsight: we had Xenomai on the allwinners 6 years ago (cubieboards) at 40,000 worst case playing videos
03:58 AM Loetmichel: *hehe* coworker is just assmbling he next 42" monitor for the frogs... *squegee squegee squegee* "Damn, lint between shielding glass and panel." *squegeesquegeesquegeesquegeesquegeesquegeesquegee* "DAMN, STILL lint in there... *repeat*
03:58 AM CaptHindsight: heh dust free
04:05 AM CaptHindsight: alexfloca: IF it's all LinuxCNC related maybe in #linuxcnc-devel or #hazzy
04:06 AM CaptHindsight: alexfloca: or post on the forums https://forum.linuxcnc.org/forum/index
04:13 AM rs[m]: CaptHindsight: what kernel (uname) do you use on the rpi4?
04:16 AM CaptHindsight: rs[m]: this is the one that comes in the 2.8 Rpi img
04:17 AM CaptHindsight: https://www.linuxcnc.org/iso/linuxcnc-2.8.0-pi4.zip
04:18 AM CaptHindsight: it's way across the room right now, I forget the version
04:19 AM CaptHindsight: rs[m]: 4.19.71
04:19 AM CaptHindsight: rs[m]: I was also working with Gentoo on the Rpi4
04:20 AM CaptHindsight: much better build
04:21 AM CaptHindsight: https://github.com/sakaki-/gentoo-on-rpi-64bit
05:14 AM Loetmichel: *wheeeze* ... just took a small sledge and made short work of half a dozen shipping crates to bring to the dump... maaan, power is still there. Stamina: zero... i sit to much on my ass and to not enough training :-(
05:17 AM JT-Cave: morning
05:42 AM Loetmichel: *MUHAHA* ... apparently i say "Michel, du bist doch so blöd daß es scheppert!" (Loetmichel, you so dumb that it rattles!) that even the coworker who doesent speak 10 words german know what i means ;) He just piped up and asked "What went wrong THIS time?" :)
05:43 AM Loetmichel: +so often
06:01 AM Tom_L: morning
06:46 AM skunkworks: CaptHindsight: don't play video..
06:47 AM skunkworks: morning
07:22 AM Eric__: Loetmichael I feel like German is one language that I have a hope of learning since it's so similar to English
07:38 AM beachbumpete1: Morning
07:41 AM sensille: Eric__: haha
07:54 AM rs[m]: Eric__: recommended reading before starting your german studies: https://faculty.georgetown.edu/jod/texts/twain.german.html
08:16 AM XXCoder: Loetmichel: lol. reminded me of that germany abuse of concercations video
08:16 AM XXCoder: guy made *really* long word
08:23 AM Eric__: they just concatenate words to make it confusing
08:26 AM sensille: there's nothing confusing about concatenated words
08:27 AM Eric__: To a native German speaker, maybe
08:27 AM Eric__: how do you make a picture that doesn't reflect? https://www.adsoftheworld.com/media/outdoor/west_australian_ballet_disappearing_dracula
08:29 AM sensille: polarized? or photoshop?
08:33 AM Eric__: might only work at certain angles
08:40 AM rs[m]: compound nouns are very useful
08:40 AM XXCoder: sadly i cant find that really funny video
08:41 AM XXCoder: aaaaand found https://www.youtube.com/watch?v=gG62zay3kck
08:41 AM rs[m]: also, german has predictable pronounciation that is mostly context-free, no suchs things as "lead" that depending on pronounciation change meaning like a spinor
08:41 AM XXCoder: that video is highly suggested lol. Loetmichel i found it!
08:43 AM Loetmichel: XXCoder: rhabarbera? jo, thats funny for a german
08:44 AM rs[m]: hehe, rhabarberbarbara
08:45 AM XXCoder: https://www.mentalfloss.com/article/54048/heres-how-crazy-long-german-words-are-made for english reading
08:46 AM Loetmichel: i have no idea what that vegetable is called in english though
08:46 AM rs[m]: Donaudampfschifffahrtsgesellschaft
08:47 AM rs[m]: Loetmichel: rhubarb
08:47 AM Loetmichel: ah, makes sense :)
08:48 AM rs[m]: i recommend searching youtube for "oachkatzlschwoaf"
08:48 AM Loetmichel: Donaudampfschifffahrtsgesellschaftkapitänspatentschulerlaubnis
08:48 AM Loetmichel: :-)
08:48 AM Loetmichel: or something similar.
08:48 AM Loetmichel: with enough willpower you can exceed the character limit in IRC ;)
08:49 AM rs[m]: what characterlimit
08:49 AM Loetmichel: per line
08:49 AM Loetmichel: ~250 chars, depending on server
08:50 AM XXCoder: 255 for default, can be set to any lesser value
08:50 AM Loetmichel: its usually a bit less to account for control codes
08:50 AM rs[m]: interesting. didn't know that.
08:50 AM XXCoder: there is "longest word" in any language, except germany and its like
08:50 AM XXCoder: best germany can is "longest in common use"
08:51 AM Loetmichel: indeed
08:51 AM rs[m]: i suppose your typical irc client breaks up longer lines
08:51 AM Loetmichel: compound words can be made up in german "on the fly"
08:51 AM Loetmichel: so thats not a thing here
08:51 AM Loetmichel: rs[m]_ it does
10:02 AM CaptHindsight: turned off GPU accel and video4linux and with 100,000 servo thread latency is <25,000
10:02 AM CaptHindsight: after 5 hours
10:03 AM CaptHindsight: skunkworks: is playing videos the only real time killer with the Rpi4?
10:10 AM CaptHindsight: a USB GPU might work well enough with the Rpi4
10:35 AM jymmmm: morning
10:41 AM jymmmm: afternoon/evening?
10:49 AM hazzy-m: @freenode_alexfloca:matrix.org: sounds more like your getting noise on the serial line when the drives power up than a software issue
11:01 AM jymmmm: hazzy-m: This is irc, no need for the @ before someone's ick
11:01 AM jymmmm: nick*
11:05 AM hazzy-m: jymmmm: both alexfloca and I are on matrix, which is bridged to the IRC room. That's probably why it looked like that if you are on IRC. All very confusing I know
11:06 AM jymmmm: hazzy-m: eh, it's all good.
11:08 AM jymmmm: hazzy-m: besides freenode, what else are you brigged/connected to on matrix?
11:35 AM skunkworks: captain_morgan: yes - youtube is a realtime killer.
11:42 AM FinboySlick: I think it's because the Youtube codec requires deterministic timing so it knows exactly when to throw an ad at you.
11:44 AM roycroft: youtube ads have gotten out of hand
11:45 AM roycroft: i've been trying to watch youtube videos online, and tolerating some ads to help the content creators, but it's gotten so bad that i've reverted to downloading videos and watching them offline
11:45 AM FinboySlick: roycroft: It's a total coincidence that they recently released a paid service to let you skip the ads.
11:45 AM skunkworks: I don't run any ad blocker and when someone stands over my shoulder and asks me how I can handle all the ads.. I just say - I don't really notice them
11:46 AM roycroft: i was attempting to watch one a week or so ago and about w minutes into the video i had to sit through four ads, withou the ability to skip any, for a minute and a half
11:46 AM roycroft: then the content came back on for five seconds
11:46 AM roycroft: and another round of ads started playing
11:47 AM roycroft: i haven't found the ad blockers to be effective with youtube
11:47 AM roycroft: but my youtube downloader works fine, albeit very slowly
11:47 AM CaptHindsight: skunkworks: for software stepping Xenomai on the Rpi4 might work well enough
11:48 AM roycroft: i don't get it
11:48 AM roycroft: youtube used to be really good at figuring out just how many ads a person would tolerate
11:48 AM roycroft: and display just under that amount of ads
11:48 AM roycroft: now they don't care
11:48 AM roycroft: it's all ads, all the time
11:48 AM CaptHindsight: ad flood, worse than old late night TV
11:49 AM CaptHindsight: it interrupts longer videos with ads as well
11:49 AM CaptHindsight: so any over 5 minutes i just download
11:49 AM roycroft: yes
11:49 AM roycroft: but i even do it with short videos now
11:50 AM roycroft: because i have to
11:50 AM FinboySlick: The gaming industry does the same thing. They make the game a lot more tedious and then offer time-saving purchases.
11:50 AM roycroft: because i cannot afford to buy a new computer after i destroy my current one when the ad that breaks the camel's back pops up
11:51 AM CaptHindsight: i downvote all ads its asks for an opinion
11:51 AM CaptHindsight: so it stopped asking me
11:51 AM roycroft: what is as annoying as the volume of ads is the content
11:52 AM roycroft: i'm *still* getting ads for an oregon concealed carry class about 80% of the time
11:52 AM roycroft: even more than those stupid insurance ads
11:52 AM roycroft: and i have no interest in and want no part of anything having to do with firearms
11:52 AM roycroft: yet somehow they think i want to see those ads
11:53 AM roycroft: but even worse than that, it's time for tons of political ads
11:53 AM skunkworks: someone in your neighborhood does.. ;)
11:53 AM roycroft: it's enough to drive a person insane
11:53 AM roycroft: like my neighbor who has been conviced of menacing for waving his handgun at a solicitor he did not like?
11:54 AM CaptHindsight: the orange pi's driver for the integrated micro has a problem and is losing steps
11:54 AM roycroft: i think it's actually the types of videos i watch, not my neighbors' behaviors
11:54 AM roycroft: machining/woodworking videos
11:54 AM CaptHindsight: it looks like a better choice than the Rpi for software stepping after that gets fixed
11:55 AM roycroft: folks associate those kinds of activities with gun loving
11:56 AM FinboySlick: roycroft: Watch lots of anime girls too, you'll get them confused.
11:57 AM CaptHindsight: using a VPN also confuses youtube, it asks me to log in for a better experience
12:03 PM roycroft: yeah, i could use a vpn or tor browser for some of the content
12:03 PM roycroft: there are geoblocks on a lot of their videos, though
12:03 PM roycroft: so if i show up from belarus or senegal or argentina i might not be able to watch what i want
12:51 PM roycroft: hmm
12:51 PM roycroft: ups have a parcel for me that was sent from jackson, tn that is to be delivered later on today
12:51 PM roycroft: i know of nothing that should be coming from there
12:51 PM roycroft: is that the location of a ups/fedex/other shipper hub, where a parcel may have been transferred to ups?
12:53 PM Rab: roycroft, I believe the major FedEx air hub is in Memphis.
12:54 PM roycroft: yes, but jackson is not all that close to memphis
12:54 PM Rab: Jackson is some 70 miles away, but maybe it's cheap real estate for a Memphis-adjacent distribution center?
12:54 PM roycroft: over 100km away
12:55 PM roycroft: i don't recall having anything on the way via fedex either though
12:55 PM roycroft: this is a total mystery
12:58 PM FinboySlick: roycroft: Don't plant the mystery seeds! ;)
12:59 PM Rab: haha
01:00 PM roycroft: no way
01:00 PM roycroft: this parcel is 13.2lbs
01:00 PM roycroft: if it were mystery seeds it would be a *lot* of seeds
01:01 PM FinboySlick: If it's just one giant seed, you really positively shouldn't plant it.
01:01 PM roycroft: even coconuts don't weigh that much
01:05 PM FinboySlick: Yeah, but what about this guy? https://vignette.wikia.nocookie.net/littleshop/images/d/de/Audrey2.jpg
01:07 PM FinboySlick: (hopefully the reference isn't too obscure)
01:14 PM CaptHindsight: been getting fake Fedex invoices today
01:18 PM CaptHindsight: FinboySlick: I'm surprised they haven't made a remake of a remake of that one yet
01:19 PM FinboySlick: It was a great little movie.
02:44 PM CaptHindsight: turned off GPU accel and video4linux and with 100,000 servo thread latency is <30,000 after ~12 hours
02:44 PM CaptHindsight: on Rpi4
02:45 PM CaptHindsight: the the integrated GPU is the real time killer
03:15 PM Deejay: gn8
03:34 PM skunkworks: CaptHindsight: how?
04:45 PM Eric__: disappointing there is a rpi cnc hat that runs grbl
04:55 PM Tom_L: how is that disappointing?
04:59 PM roycroft: i wasn't going to ask that, because i thought i was overlooing something obvious :)
05:09 PM Rab: Eric__, is it an Arduino rubber-banded to a superfluous Pi?
07:00 PM roycroft: ok, this is interesting
07:01 PM roycroft: ups arrived with my mystery parcel
07:01 PM roycroft: it was addressed to me
07:01 PM roycroft: and it contains a hello kitty manicure set and hair dryer
07:01 PM roycroft: with no paperwork
07:01 PM roycroft: it was shipped from "jz enterprises"
07:02 PM roycroft: i did not think that hello kitty had been a thing since the '90s
07:02 PM roycroft: it was certainly never a thing for me
07:03 PM roycroft: i shall take all proper precautions
07:03 PM roycroft: by not plugging in the hair dryer nor planting any of the stuff in the ground
07:06 PM * roycroft needs to figure out how to turn his workbench upside down and then lift the inverted bench onto saw horses without injuring himself or the bench
07:14 PM Eric__: Rab, was hoping for direct access to the stepper drivers so it could run lcnc
07:15 PM Eric__: I have a project I want to do on the cheap and an rpi with low cost stepper drivers and qtpyvcp would be perfect
08:04 PM CaptHindsight: skunkworks: I'll ask and post it somewhere
08:05 PM Tom_L: any ideas?
08:05 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/configs/NEW_MILL_SHOP_2.7/estop_codesnip.hal
08:05 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/configs/NEW_MILL_SHOP_2.7/estop1.png
08:06 PM Tom_L: i've been using simpler estop code but wanted to figure this out
08:06 PM Tom_L: it's JT-Shop's example estop latch
08:14 PM Tom_L: i don't know what triggers iocontrol.0.user-request-enable
08:41 PM Tom_L: ok, nevermind i figured it out
08:43 PM Eric__: it shouldn't be too hard to rebuild a rt-prempt kernel, right?
08:43 PM Tom_L: i've done it
08:44 PM Tom_L: there might be a few switches you may want to know about
08:44 PM Eric__: the kernel on the ISO is a stock debian kernel, or custom built
08:44 PM Eric__: ?
08:44 PM Tom_L: it may have a few things checked or unchecked
08:44 PM Tom_L: in the dialog box
08:44 PM Tom_L: don't ask me what they are :)
08:46 PM Tom_L: you could try a stock one and test the latency
08:52 PM roycroft: there are a number of things to do to build a custom linux kernel
08:52 PM roycroft: the internet knows exactly how to do it though
08:52 PM roycroft: so just ask it
08:52 PM roycroft: or wait until tomorrow and ask jt for the kernel you need - he always keeps a bunch of them around
08:53 PM Eric__: I know how to build a kernel, I asked the question I wanted the answer to
08:53 PM roycroft: you asked two questions, actually
08:54 PM Eric__: true
08:54 PM Tom_L: jepler might have insight on any settings
08:54 PM Eric__: 1st question is do you have to apply a patch
08:54 PM roycroft: i haven't built a pre-empt kernel ina long time
08:54 PM roycroft: that used to be the case
08:54 PM Eric__: I think it's a main-line kernel option now
08:54 PM roycroft: back in the days around jessie
08:54 PM roycroft: i'm not sure if it is any more
08:55 PM roycroft: you're probably correct
08:55 PM roycroft: because linuxcnc isn't as far behind current debian as it used to be
08:55 PM roycroft: and the excuse used to be the kernel patches
08:55 PM roycroft: so if that excuse went away it would stand to reason that linuxcnc would be more up-to-date than previously
08:56 PM Eric__: no rtai option yet for 2.8
08:56 PM roycroft: but you're talking to two people who have done this but are by no means experts (i hope tom_l does not think i'm out of line in saying that)
08:57 PM roycroft: and while i'm not sure if jt considers himself an expert, he keeps up on linuxcnc distros and would probably be able to tell you exactly what you want to know
08:57 PM Eric__: it looks like there are packages available for preempt-rt on buster, but the links take forever to load an I'm not on a debian system
08:58 PM roycroft: i have figured out how to safely invert my new workbench and put it on sawhorses, but it involves using a hydraulic lift table, and it's a lot of work pulling it out and setting it in place
08:59 PM roycroft: so that's a tomorrow thing
08:59 PM roycroft: i did some of the work today, but it's time to make dinner, not work in the shop
10:38 PM veegee: CaptHindsight I bought this: https://www.amazon.ca/gp/product/B01JGF8DT4
10:38 PM veegee: Feels like a good kit
10:39 PM veegee: My cat likes to play with the bright yellow caps on the end of the hoses so I guess she approves :)