#emc-devel | Logs for 2006-09-11

[01:48:12] <jepler> jmkasunich: I remember that when we were testing the tp, we saw that the Xacc signal was very "noisy". I have been trying to convince myself whether a 'dddt' block, which produces both a first and second derivative, and holds the temporary first derivative value as a double, would be any better.
[01:49:19] <jepler> I am leaning towards doubting it, because the trouble is that the 'input - last' difference may not have too many significant bits when calculating the first derivative
[02:30:07] <jepler> I just had an interesting idea
[02:30:19] <jepler> 'loadrt ddt names=dx,dy,dz'
[02:30:34] <jepler> it would create instances named ddt.dx, ddt.dy, etc
[02:31:40] <jmkasunich> hmm
[02:33:04] <jmkasunich> seems like its something you'd either want to do across the board, or not at all
[02:35:03] <jmkasunich> my "someday" goals for HAL are "on request" instantiation of blocks, rather than using "count" or something like it to make N of them up front, and then being stuck with that quantity
[02:35:43] <jmkasunich> if/when that happens, it seems only natural that the "newblk" command would allow the user to name the new instance
[02:35:50] <jepler> yeah
[02:35:57] <jepler> if you are working interactively that would be ideal
[02:35:58] <jmkasunich> perhaps the "names" thing should be deferred until then?
[02:37:24] <jmkasunich> if you are assigning names, you might want the user assigned part to be a prefix, not a suffix, for example
[02:37:49] <jmkasunich> so halcmd show X would show you X.ddt.blah and friends
[02:38:46] <jepler> http://linuxcnc.pastebin.ca/166621
[02:39:48] <jmkasunich> ah, so you completely drop the ddt and use the user specified names only
[02:39:53] <jmkasunich> that could work
[02:40:55] <jepler> then *ugh* you could implement 'newblock' by doing a partial 'save', 'unloadrt', 'loadrt names=....,newname', and then 'load'
[02:43:21] <jmkasunich> ugh is right
[02:43:48] <jmkasunich> newblk (and newthread, and a few other things) needs deeper changes
[02:55:11] <jepler> having undoubtedly broken the tree, it's my bedtime...
[02:55:19] <jmkasunich> heh
[02:56:15] <jmkasunich> what do you mean by "provide fperiod"
[03:08:02] <jmkasunich> I see
[03:08:21] <jmkasunich> bedtime for me
[12:52:38] <alex_joni> morning all
[13:24:20] <jepler> hi alex
[13:34:38] <alex_joni> hi jeff
[13:36:57] <alex_joni> do you maybe know how to install a certain version of a deb?
[13:37:01] <alex_joni> apt-get install ppp version ?
[13:37:21] <cradek> install package=version
[13:37:59] <alex_joni> thanks chris ;)
[13:38:05] <cradek> * cradek gently reminds alex_joni about the apt-get manpage
[13:43:00] <alex_joni> I DID look there
[13:43:05] <alex_joni> but too briefly ;)
[13:43:18] <alex_joni> http://dsplabs.utt.ro/~juve/blog/index.cgi/projects/01157974398
[13:49:06] <alex_joni> cradek: how does that look?
[13:50:51] <cradek> very interesting! welded and powder coated?
[13:51:42] <cradek> have you measured how upright it is yet?
[13:51:47] <cradek> any plans for a spindle?
[13:53:11] <alex_joni> welded and powder coated
[13:53:20] <alex_joni> didn't measure yet, not sure I have with what
[13:53:29] <alex_joni> I think I'll put a probe on it ;)
[13:53:37] <alex_joni> or a very small dremel
[13:53:52] <alex_joni> wanted to ask you one thing though
[13:54:31] <alex_joni> on the PMinMO design there's a variable resistor to set current through the stepper
[13:54:36] <alex_joni> how do you set that up?
[13:55:22] <cradek> I can think of a few ways - easiest would be to put a scope across the current sense resistor
[13:55:52] <cradek> or just set the reference voltage according to the datasheet (I think there is even a test point on the board for that)
[13:56:00] <jepler> does it use a 1-ohm power resistor? If so, set the voltage out of the variable resistor to 1V per amp
[13:56:36] <cradek> yeah that
[13:56:53] <cradek> (I don't remember how I set mine)
[13:57:16] <alex_joni> there are 2 .5 Ohm resistors
[13:57:19] <alex_joni> those you mean?
[13:57:36] <cradek> yes
[13:57:43] <alex_joni> ok, so 1V / amp ?
[13:57:58] <cradek> no, not with .5 ohm resistors
[13:58:08] <cradek> the .5 ohm resistors are used to sense the current
[13:58:20] <cradek> this is compared to Vref (the var resistor)
[13:59:04] <jepler> so it would be .5V/amp
[13:59:26] <alex_joni> right..
[14:55:40] <alex_joni> cradek: found a small problem with the install script
[14:56:01] <alex_joni> just wanted to install it on a friends PC (dapper), but he had no new line at the end of /etc/apt/sources.list
[14:56:26] <alex_joni> which cause the deb http://www.linuxcnc.org/ dapper emc2 line to get added to the end of the previous line
[15:01:23] <jepler> text files that don't end in a newline are broken
[15:01:42] <jepler> instead of "fixing" the script, this user should be chastized so harshly for having such a sources.list that he switches to Windows XP
[15:06:49] <cradek> I halfway agree with jepler
[15:06:56] <cradek> I don't think that's a problem with the install script
[15:07:07] <cradek> >> is a well-established way to append a line to a file
[15:07:39] <cradek> do you know what put the last line in his file? was it a ubuntu program, or the user?
[15:07:46] <alex_joni> user
[15:08:14] <alex_joni> but maybe we can echo an empty line before the deb.. ?
[15:08:20] <alex_joni> it really can't hurt
[15:08:30] <alex_joni> or maybe a comment : #emc2 repository
[15:11:38] <cradek> I guess I don't mind if you want to add an empty line
[15:11:57] <cradek> but you should also tell your user to not do that...
[15:13:52] <Lerneaen_Hydra> 'lo cradek
[15:14:06] <cradek> hi
[15:14:35] <jepler> I would like to set up something to automatically put the latest PDF and HTML documentation on the website .. built nightly or so
[15:14:52] <jepler> I can run the build on one of my systems, but I'd need ssh/rsync access to the web server
[15:14:59] <jepler> is this doable? Who would I ask?
[15:15:20] <cradek> I think I have access to do that
[15:15:27] <cradek> you'd have to ask swp
[15:18:11] <cradek> I wonder if it would be better to have jmk do that from the compile farm
[15:18:29] <cradek> I think he's already set up to put stuff on the webserver (the farm output)
[15:19:17] <jepler> *** Fatal Error --- but easy to fix ***
[15:19:17] <jepler> Cannot have '.' in file-name prefix, else dvips fails on images
[15:19:17] <jepler> Change the name from ../docs/src/code/Code_Notes.tex and try again.
[15:19:21] <jepler> huh I haven't seen this error before
[15:19:24] <jepler> (trying to build docs on a fedora machine)
[15:19:41] <cradek> huh
[15:56:43] <alex_joni> http://www.linuxcnc.org/docs/html/
[16:00:19] <jepler> yay
[16:01:03] <Lerneaen_Hydra> is that an autocompile?
[16:01:55] <jepler> no, it was done manually
[16:02:16] <jepler> but I hope it will be automatic in the near future
[16:02:17] <Lerneaen_Hydra> oh, ok
[16:02:27] <Lerneaen_Hydra> yeah, sounds nice
[16:05:45] <jepler> huh some of the images are just not right at all: http://www.linuxcnc.org/docs/html/hal/rtcomps/index.html
[16:06:54] <alex_joni> jepler: did you try optional stop again?
[16:07:03] <jepler> alex_joni: no, not yet
[16:07:22] <alex_joni> jepler: ok, no problem
[16:07:32] <alex_joni> * alex_joni will be away for the next 2 days
[16:09:04] <jepler> travelling again? you seem to do that a lot
[16:09:53] <alex_joni> yeah, short trip to germany
[16:10:04] <alex_joni> I'm back on thursday though, so it's ok
[16:10:28] <jepler> have a goodt rip
[16:11:19] <jepler> good trip
[17:31:32] <alex_joni> jepler: only tomorrow morning
[17:31:37] <alex_joni> tonight I'm still around :)
[20:13:09] <cradek> appears that the EMC version of classicladder-0.7.3 was run through a
[20:13:09] <cradek> formatting program of some sort, because when I do a diff on the two
[20:13:11] <cradek> directories, I get large sections of basically every .c and .h file
[20:13:25] <alex_joni> cradek: that is true
[20:13:36] <alex_joni> it was part of the old build system
[20:13:36] <cradek> how many times do I have to say it!?
[20:14:02] <alex_joni> what? that formatting is bad?
[20:14:12] <cradek> yeah
[20:14:29] <cradek> I feel bad for him
[20:21:06] <alex_joni> cradek: why?
[20:22:05] <alex_joni> I think it's nice of him to try to help on that part :)
[20:22:17] <alex_joni> it's a tough thing to do though
[20:22:49] <cradek> yes, and made 100 times harder by some person running indent
[20:23:36] <alex_joni> maybe he can run indent on both versions now
[20:23:42] <alex_joni> to get something consistent
[20:23:52] <alex_joni> then apply the changes on the untouched latest version
[20:24:22] <cradek> yes that might be the least painful thing to try...
[20:25:40] <alex_joni> anyways.. I'm off to sleep.. early start tomorrow
[20:25:46] <cradek> goodnight
[20:25:46] <alex_joni> not sure when I'll be back online
[20:25:47] <cradek> have a good trip
[20:25:52] <alex_joni> bye guys
[20:25:54] <alex_joni> thanks
[20:25:59] <alex_joni> night all