#robotics Logs

Mar 30 2012

01:36 rue_house sorry I went right to sleep after work
01:36 katsmeow-afk and then what happened?
01:37 rue_house I woke up and ate
01:37 rue_house and I'm just on my way back to bed
01:37 katsmeow-afk oh
01:37 katsmeow-afk try drinking 50g of protien yet?
01:38 rue_house o
01:38 rue_house no
01:38 katsmeow-afk might help
01:38 rue_house apple wants me to upgrade the iphone I just got to 5.1 of their os, but doing so will lose all the data on the phone
01:38 rue_house so forget that
01:38 rue_house its a phone, it dont need a new os
01:39 katsmeow-afk the won't do a backup if you take it to a store?
01:39 rue_house I just got it a week ago, I'm not going thru a long process to upgrade its firmware
01:39 katsmeow-afk no, not you, i said the store
01:40 rue_house >> apple ios 5.1 will delete all your contacts, notes, images, and music <<
01:40 rue_house na, I dont have time
01:40 tsmeow-afk
01:42 katsmeow-afk man, led prices have tanked, humans are not buying qty10 1w wite led even for $ & $3.29s&h
01:42 katsmeow-afk err
01:42 katsmeow-afk man, led prices have tanked, humans are not buying qty10 1w white led even for $1 & $3.29s&h
01:43 katsmeow-afk ditto peltiers
01:43 katsmeow-afk 100w peltier, $1 + $4.29 s&h
01:47 katsmeow-afk ...
01:47 katsmeow-afk ok, gnites
02:10 rue_house the hollywood stars are real right? I cant find them on google earth
02:16 rue_house I dont belive it, there is no GIS data on the walk of fame
02:18 rue_house I'll never know who is between cher and james dean
02:30 theBear james dean has the decency to wear clothing on the lower half of his body that isn't open at the crotch, and on the top half he only shows a modest amount of chest at the most... that's how i tell the difference <grin>
02:30 theBear rue_house, i am led to believe they are real, no idea where they are tho
02:36 rue_house yea there is no map of the stars positions along the walk of fame
02:37 rue_house its not even flagged on google earth
02:37 rue_house my concusion is that its because nobody cares, and thus, I shouldn't care either
02:38 rue_house I had to hack the verification letter from apple to activate my apple ID
02:38 rue_house wtf!?
03:52 Tom_itx http://www2.electronicproducts.com/World_s_largest_laser_fired_displays_record_breaking_power-article-fajb_NIF_laser_march2012-html.aspx
03:52 Tom_itx is it me or does the staff all look tan?
05:30 charolastra hi, could someone recommend a solution for near realtime streaming on linux? would be ideal if it works on an enbedded CPU
06:39 theBear charolastra, ummm.... if you check for any sync/delay drift issues, i've often found DISPLAY=remotemachine:0 mplayer tv:// device=v4l or something to that effect to work quite well, just in some cases (and when i did this for long periods i wasn't so good at mplayer sync-problem fixing,) over time one machine would drift ahead ever so slowly and eventually the buffer couldn't take it, from memory if the sender (mplayer/embedded/cam machine) drift
06:39 theBear s forward and you have either kind of framedropping or maybe autosync set it can fix that , no doubt a littl efiddling would get the other way working, specially if there's no sound involved... tho usually it takes a LONG time to drift to a point where there is a noticable delay between real world input and video output... also depending on available bw and stuff vo=xv MIGHT be good and/but will use the same bandwidth regardless of window size 'c
06:39 theBear os it scales at the xserver/receiving end, whereas something like vo=x11 -zoom will do software scaling at the mplayer end and scale bw accordingly.... i suppose ideally you'd pick v4l/input resolution to suit available bw/desires then use a 'smart' driver like xv to scale using xserver/graphics hw at the non-sending end
06:39 theBear does THAT answer your question? :)"
07:03 charolastra theBear: to be honest, it doesn't ;)
07:03 theBear hehe, what kinda/power cpu you got, and what knida network/whatever connection ?
07:03 charolastra actually i'm just looking for a way to push frames with a small ARM processor over the net; withouth >1 second lag and better than 1-2 FPS ;)
07:04 theBear have a quick play (even on 2 'normal' machines one of which has a cam/whatever you plan on sending input,) lookup umm, i'll find you a basic working cmdline for a v4l device
07:04 charolastra actually it's a dockstar; 1,2GHz ARM7 (i think); and with net i mean the internet
07:06 charolastra i've looked into RoboCortex as they seem to have real nice x264 encoding; but it's too much for that CPU and at the moment it doesn't run with my openCV version
07:07 theBear DISPLAY=displayhost:0 mplayer tv:// -tv driver=v4l2:device=/dev/video2:input=6:contrast=-20:brightness=30:width=640:height=480 -vo xv if you don't need an option you cna generally drop them just fine, oh and fps, i forget the setting for that, but note (from memory,) that it wants to be in the v4l: string of options vs just the mplayer -fps switch, cos you want to change the capture device fps for performance reasons
07:07 charolastra what kind of bandwith untilisation do you see with that?
07:08 theBear oh, you need real compressed ? a cpu that fast SHOULD be able to compress in realtime just fine (at a guesstimation) but not sure mplayer can do that, unless maybe you can do something like err, maybe mplayer blah -vo pipe or maybe file (-vo help will list options) and drive that thru ffmpeg and i dunno, netcat or omething
07:08 theBear lemme try
07:09 charolastra for now i'm using mjpeg-streamer as my camera delivers a mjpg stream; works fine in LAN but fails over the internet because of too much traffic/TCP delay issues
07:09 charolastra oh yes, i fogot: it should run over UDP :)
07:10 theBear ummm, pretty sure the network part of the chain is running "640x480 @ [rawyv12] vfm: raw (RAW YV12)" and 24 fps, or whatever .au pal tv standard is, maybe 24.97, is about 7 mb/second according to gkrellm
07:10 charolastra muahhaah, waaay too much
07:10 theBear but that is raw i guess 12 bit, probably padded to 16 per pixel for ridiculous numbers of colours, and high frame/res... lemme try
07:10 theBear wait and see
07:11 charolastra my wlan can only push 1mb/s :(
07:11 theBear any idea of desired resolution ?
07:12 charolastra well, VGA would be nice; 320x240 is workable; quality can be in the gutter as long as fps something like >= 7fps
07:12 charolastra and it should fit though consumer DSL (something like 60kb/s)
07:12 charolastra sounds trivial, but isn't :(
07:19 theBear hmm... i can't seem to convince bt878 v4l2 device to change fps, or for mplayer to use a different colourspace for output
07:19 charolastra hmm, what's your default fps?
07:19 charolastra 5?
07:21 theBear now i getting somewhere, and that is how i watch the dtv boxes from in here when myth is grumpy (usually <grin>) so it's prety much tv spec by default, but i'm getting damned close
07:23 charolastra hehe
07:39 theBear ffs, i got it down to about 1.5m/second uncompressed 10fps 320x240, now i lost i can't remember which of the 100's of test cmdlines it was :)
07:40 theBear there's like 50 different colour formats you can feed to various v4l drivers and converters and out of the v4l2 driver, but it's just a list of names, nothing to hint how padded it is or even how many bits a lot of them are
07:42 theBear right now pretty sure it's donig uncompressed 16bit*320x240*10fps and it's looking steady bang on 3mb/s
07:42 Steffann steady bang :)
07:43 theBear but if i could workout how to get it down to 8bit or so, that'd be a good start
07:43 theBear heh
07:43 theBear and i suspect some webcams may well allow you to output/receive mjpeg or similar, not sure which tho
07:43 theBear that would be a huge saving if you got an output to receive it
07:45 theBear lol, 70kb/s or so with aalib output :)
07:46 theBear that's totally decipherable as a tv show (NOT)
07:46 theBear but sure does cut things down <grin>
07:50 theBear hmm.. this machine doesn't seem to have any unicode/high fonts
07:52 theBear but if yer good with pipey stuff, i'm sure you could work something sensible out, very possibly involving ffmpeg as a realtime translator
07:54 theBear meh, can't find an example, i gotta do something
07:58 theBear oh silly boy, it was the headless machine that doesn't have unicode support, tho i suppose if i using remote x displays, it's worth sticking it on
07:58 theBear plus then i can get hires ascii-art-output :)
08:23 charolastra_ hehehe
09:45 sw0rdfish hmmmmmm
09:47 sw0rdfish uhhh how many inches is an A4 paper again?
09:47 sw0rdfish think I want to buy an ebook reader that is gentle on the eyes
09:47 sw0rdfish making you feel just as if you're reading a normal physical book
09:48 sw0rdfish I heard the kindle is small
09:49 rue_house http://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1052e/
09:49 rue_house katsmeow-afk,
09:50 rue_house letter is 8.5"x11"
09:50 sw0rdfish hi rue_house :)
09:50 sw0rdfish I found this btw
09:50 sw0rdfish http://openbookproject.net/electricCircuits/
09:51 sw0rdfish hope its good... its recommended by several ppl
10:05 sw0rdfish http://www.willowgarage.com/pages/software/overview
10:05 sw0rdfish best robotics software ^^?
10:20 charolastra_ afaik the only robotics software if you want something open; otherwise i've heard of microsoft robotics studio
10:22 sw0rdfish yeah
10:55 -calvino.freenode.net:#robotics- [freenode-info] help freenode weed out clonebots -- please register your IRC nick and auto-identify: http://freenode.net/faq.shtml#nicksetup
11:08 rizlah Anyone know any good books on math?
11:09 sw0rdfish what level?
11:12 rizlah Uhh, algebra onwards
11:18 sw0rdfish hmmmm well I'm using the "Demystified" collection actually... but yeah I really need math revision from the lowest level like pre-algebra
11:18 sw0rdfish but you could also ask in #math rizlah
11:19 sw0rdfish ##math*
11:20 rizlah What books are you using for pre?
11:20 rizlah Asked in math but they don't really give decent answers.
11:20 rizlah Seeing as every college/school uses a different book, it's hard to get a single name
11:24 rizlah brb
11:25 sw0rdfish hmmmm
11:25 sw0rdfish http://www.ebay.com/itm/6-IN-1-Solar-Car-Dog-Airboat-AirPlane-Robot-DIY-Toy-Kit-/180853016928?pt=LH_DefaultDomain_0&hash=item2a1bae0960#ht_3153wt_928
11:25 sw0rdfish wow that looks good (extra thingy) to work on for a rookie like me :)
11:28 sw0rdfish but uhhh, its not programmable or anything really... I should save my 7 dollars to buy something more useful
13:23 katsmeow-afk rue : http://www.mouser.com/Semiconductors/Data-Conversion-ICs/ADC-A-D-Converters/_/N-4c43g?P=1yzv7ipZ1yzvrfwZ1yztbjt&Keyword=adc&FS=True&SAP=true&Ns=Pricing|0
13:32 katsmeow-afk a $40 1Gsps adc chip, with a 4x4 analog mux in it for making 1,2,4 input channels
13:34 katsmeow-afk while this is a amazing price drop, it bears repeating that 1 gsps is still only 10 samples of a 100 Mhz signal, and in single-shot mode you can still lose a ton of information about the signal with only 10 samples of it
13:35 katsmeow-afk for 50Mhz, it's prolly acceptable, and for 25Mhz it's prolly quite useable, for audio it's amazingly great
13:36 katsmeow-afk for the oscope rue pointed out, the 1 gsps chip is running "only" (heh) 500 Msps in 2-channel mode
13:38 Steffanx I have that scope :)
13:38 Steffanx Works nice for the things i use it for
13:41 katsmeow-afk ok
13:42 Steffanx :p
13:42 katsmeow-afk for some things, a digital simply won't work, for some other things it's better
13:42 katsmeow-afk that's why there are hybrid scopes
13:49 SolarNRG Would an L298 drive these things: http://i.imgur.com/aJvY1.jpg
14:54 sw0rdfish hmmmm
17:16 katsmeow-afk the Rigol DS1000E has already been cloned as the Siglent SDS1062C
17:17 katsmeow-afk i dunno how the specs are diff or same, but it's cheaper
17:20 katsmeow-afk "The volume of the oscilloscope is cabinet and it is portable"
17:21 katsmeow-afk �Accidence� chapter describes the front panel; display area of the oscilloscope;
17:23 katsmeow-afk to convenience users to operate them, the panel contains knobs and buttons.
17:24 katsmeow-afk these are the opinion buttons, you press to accidece these opinions by virtue of them
17:25 katsmeow-afk chapter 1.1.3 Unstanding the Display Information
17:28 katsmeow-afk hmm, the siglent appears to be a fixed 4 channel plus trigger
17:28 katsmeow-afk The FFT process mathematically converts a time-domain signal into its frequency components. You can use the Math FFT mode to view the following types of signals:
17:28 katsmeow-afk ? Analyze the Humorous wave in the Power cable.
17:28 katsmeow-afk ? Test the Humorous content and distortion in the system
17:32 katsmeow-afk hmm
19:04 Tom_itx what is Limnoria?
19:04 Tom_itx not the but
19:04 Tom_itx bug*
19:04 Tom_itx the software package
19:10 dunz0r A modified version of the supybot-bot iirc
19:14 Tom_itx link?
19:59 katsmeow-afk http://aur.archlinux.org/packages.php?ID=56143
20:00 katsmeow-afk http://supybot-fr.tk/Accueil
20:01 katsmeow-afk irc.tc/freenode/limnoria-bots/Cached
20:01 katsmeow-afk You +1'd this publicly. Undo
20:01 katsmeow-afk 10/22 users: This channel is for bot testing purposes. || For help, see #limnoria.
20:02 katsmeow-afk IRC Networks > OFTC > #limnoria-botshttps://search.mibbit.com/networks/OFTC/%23limnoria-botsCached
20:02 katsmeow-afk Browse networks > OFTC > #limnoria-bots. No such channel.
20:05 katsmeow-afk Tom, just an idea for a box for your pcb : http://www.terasic.com.tw/attachment/archive/593/image/image_61_thumb.jpg <<== don't put it in a box, just sammich it tween two milled sheets of plexi
20:06 Tom_L someone did that with one of mine
20:13 rue_house kat neat method
20:13 Tom_L rue_house
20:14 Tom_L what are you working on tonight?
20:14 Tom_L katsmeow-afk wanna play?
20:20 katsmeow-afk beg pardon?
20:20 Tom_L i'm messin with the bot
20:20 Tom_L didn't know if you were interested
20:21 katsmeow-afk a lil
20:21 Tom_L trying to figure out a few features
20:21 Tom_L i'm in ##avr with it
20:21 Tom_L since it's basically empty
20:21 katsmeow-afk i think you are inventing the wheel again, making incompatable wheels in search of a truck to go on, but i'm courious
20:22 Tom_L so give up?
20:22 katsmeow-afk giving up is courious, give up on which?
20:23 rue_house tonight I wanna play
20:24 Tom_L with what?
20:24 rue_house I'm gonna start by turning the tent rght-side out tho
20:24 rue_house I gotta go to work tommorow
20:24 katsmeow-afk yeas, silly idea putting the rainy side on theoutside
20:24 rue_house kat, did you se the cute little scope?
20:25 katsmeow-afk keep the rain inside where you can gather it easily
20:25 rue_house katsmeow-afk, it looks like a pretzel right now, I'm gonna make it back into a tent
20:25 katsmeow-afk i saw and commented on the lil scope
20:25 rue_house oh I'm gonna go see what you said
20:26 rue_house ah, well my point was that it was neat, not to be the best scope ever
20:26 rue_house I'm looking at 100ksps for the one I'm making
20:27 rue_house or lesss
20:27 katsmeow-afk i wold not use 100ksps for as high as audio, but then you aren't
20:27 katsmeow-afk however the cost and effor to make a 10ksps, you can make a 20msps
20:31 rue_house its for mechanical responce times tho
20:32 katsmeow-afk yeas, that one is, then you build a WHOLE NOTHER ONE for other stuff?
20:33 rue_house or make the core upgradable
20:33 rue_house I'm establighing a protocol and pc side app
20:33 katsmeow-afk or make it fast enough first
20:33 rue_house from there I can make whatever data converter I want
20:34 katsmeow-afk really, a TL084 is same cost as a LM386, but 15x faster, so why not use it?
20:34 katsmeow-afk etc
20:34 rue_house I'm going with the "make it, then improve it" instead of the "spend all your time designing something you can never build"
20:35 katsmeow-afk i am just saying, do the same work, exactly the same, but use faster parts, never build DOWN to a spec
20:35 rue_house hey! i'm gonna go put a tent back togethor, ot atleast sort out all the parts in the yard
20:35 rue_house I dont have parts to make anything better kat
20:35 katsmeow-afk i know darned well you have opamps faster than 0.7mhz
20:36 katsmeow-afk if not, you can make them for $0.005 per transistor
20:36 katsmeow-afk and i know you have transistors
20:37 katsmeow-afk i grabbed boards people threw away that have 600Mhz opamps on them, i bet you do too
20:38 katsmeow-afk i grabbed literally 100's of 20Mhz adc on them, i can send you a couple, then you don't need to limit to 10ksps
20:41 Tom_L http://www2.electronicproducts.com/Company_claims_its_maglev_travel_system_could_be_faster_than_jets-article-fajb_et3_march2012-html.aspx
20:42 katsmeow-afk they been claiming that for 30 yrs, and it's true, if you can keep cows and trucks off the rails,, else it's just anotehr Amtrack
20:42 Tom_itx it's a tube
20:43 katsmeow-afk ok
20:43 horar hi folks
20:43 katsmeow-afk hi horar
20:43 Tom_itx they don't get the accel and decel right, it could suck your brains right out
20:46 horar after way more trial and error than I care to admit to, I finally got PID motor control working on my robot.
21:08 Tom_itx it is a trial and error process
21:10 horar In the end, tuning the P, I and D weights was very easy.
21:10 horar The key point that I'd been getting wrong all the time was that without a high enough sampling rate, it's simply not going to work.
21:11 horar So shaft encoders have to be on the motor shaft. The output shaft of the gear box (i.e. the wheel) is moving far too slowly.
21:34 katsmeow-afk correct
21:35 katsmeow-afk if you sample the wheel, the timeframe for averaging must be extremely long, at which point the robot is down the street a ways
21:39 katsmeow-afk or it's worn a hole in the carpet
21:55 katsmeow-afk .
22:13 katsmeow-afk Cooking with Poo wins Diagram Prize for oddest title
22:14 katsmeow-afk "We knew the whole world loved Poo but now its official!," said Anji Barker, a senior social worker at the charity Urban Neighbours of Hope.
22:18 katsmeow-afk "Garching is not something you do, it's someplace to be"
23:37 katsmeow-afk 1 white stylus for nintendo ds lite console
23:37 katsmeow-afk $0.01 + free s&h
23:38 katsmeow-afk 1 Piece New Paper Clip Paperclip ; Location: USA ; Returns: Accepted within 7 days ; 0 Bids $0.01 Pickup only: Free
23:39 katsmeow-afk there's also a penny for sale, $0.01 + free s&h