#robotics Logs

Jul 20 2012

00:00 rue_mohr are you back or renting?
00:00 rue_mohr (internet)
00:00 katsmeow-afk wifi will not work, to many r and f's in the air here, and winders will not re-establish a encrypted airpath
00:00 katsmeow-afk renting?
00:01 tsmeow-afk has been being ignored by rue_shop3 in garf for h
00:02 furrywolf I just got done putting my truck back together a few minutes ago... you got to fix lightning, I got to fix a perpetually sticky carb needle, which turned into a multi-day project thanks to one of my gas cans being filled with water instead of gas...
00:03 katsmeow-afk furry, i need something non-standard, that looks transparently like a 100mbit or slower lan copper wire
00:03 katsmeow-afk yea, water isn't even good to find fuel leaks with, really
00:03 furrywolf what about fiber optic?
00:03 katsmeow-afk fiber is still physical
00:04 katsmeow-afk why not leaving the "fiber" pat out?
00:04 furrywolf the seal under the cap died, and in the ~1yr since I last used the gas can, it seems about a quarter of the can became water... was dumping it in the jeep, when I realized there was water coming out not gas.
00:04 katsmeow-afk just shoot the laser thrut he air 10ft and back to copper?
00:04 furrywolf you could, but the dielectric properties of fiber are extremely good, possibly even better than air.
00:05 katsmeow-afk i know they are, use stroger lasers
00:05 furrywolf so if the goal is lightning protection, a short fiber run would be entirely off-the-shelf and not need aiming, etc.
00:05 katsmeow-afk fiber has a surface, which collects dirt, soot, and water, and becomes conductive
00:06 furrywolf so does your floor, walls, whatever the router is attached to, etc.
00:07 katsmeow-afk please do notmake my goal or wireless be as difficult a chat as trying to get the telco to replace a bad modem
00:07 furrywolf http://www.ebay.com/itm/Zonet-ZFS3008F-7-1-Port-10-100Mbps-Fast-Ethernet-Switch-100Mbps-Fiber-/221075628546?pt=COMP_EN_Hubs&hash=item3379226202 not tooo bad...
00:07 katsmeow-afk what does my router have to do with a 10ft rf or laser link?
00:07 furrywolf if you run the fiber down to the floor and back up to the other router, the path along the jacket is just as long as the path along the floor anyway.
00:08 katsmeow-afk i have no floor outside
00:08 furrywolf you have ground. same thing. unless the fiber is stretched tight between the endpoints, its jacket is not going to make a shorter path than arcing along existing objects.
00:09 katsmeow-afk fuck, damnit, tell me what is WRONG with a 10ft AIRGAP
00:09 katsmeow-afk or 50ft, whatever i can do for cheap?
00:09 furrywolf that it'll be harder to construct, more expensive, and less reliable. aiming lasers is highly annoying, and it'll be susceptable to dirt, mositure, etc. and you said you can't use wifi.
00:10 katsmeow-afk i went and got on camera at a homeland-secured installaton to get back online, and it wasn't to hear you tell me i cannot use a radio link
00:10 furrywolf and any other rf technology will be expensive.
00:10 orlok katsmeow-afk: over what distance?
00:10 furrywolf YOU told ME you couldn't use a radio link. "to many r and f's in the air here"
00:10 katsmeow-afk seriously expensive? a handfull of 2N4401 and a NE602 is expensive??
00:11 katsmeow-afk no, i said i could not use a WIFI link
00:11 furrywolf I'm not the one telling you that you can't do it. I'm the one that suggested you do it!
00:11 orlok katsmeow-afk: wifi as in a specific frequency/protocol, or you mean for long half internet uplink?
00:11 orlok uhh, long haul, even
00:11 katsmeow-afk i have no probs with dropping below 100Mhz and blastng as much power directionally as i need to shoot 10 FEET on my property
00:12 furrywolf if you have the skills to build your own rf rx/tx pair in the ghz range, with firmware, etc, go for it... I for one do not.
00:12 katsmeow-afk i never said ghz, that is where the problem is
00:12 katsmeow-afk orlok, even sitting the wifi modem behind the computer with the antennas touching, i STILL cannot maintain a link
00:13 orlok hmm
00:13 orlok put the door back on the microwave
00:13 orlok and stopdefeating the safety interlocks
00:13 orlok ?
00:13 katsmeow-afk i have 300 cable boxes, surely i can build some sorta rf link
00:13 furrywolf how about wifi with directional antennas? I have a hard time imagining any level of background noise could swamp them. like two of http://www.ebay.com/itm/2-4GHZ-15-dbi-WIFI-ANTENNA-15-X-12-GRID-TYPE-LANCE-MMDS-ITFS-N-MALE-CONN-/251109919483?pt=US_Directional_Network_Antennas&hash=item3a77514afb
00:13 katsmeow-afk there's a microwave farm on the other side of the valley
00:14 katsmeow-afk furry, even sitting the wifi modem behind the computer with the antennas touching, i STILL cannot maintain a link
00:14 orlok they grow microwaves in alabama? :)
00:14 furrywolf have you tried with other hardware? that sounds more like defective equipment.
00:14 furrywolf also, direction antennas are pretty good at not picking up noise, especially if you make sure not to aim the sidelobes at the source...
00:14 furrywolf directional
00:15 katsmeow-afk i have tried, at the risk of lightning routinely destroying tons of data and work, you think i didn't try?
00:15 furrywolf I have no idea what you've tried, or how much of a problem lightning is in your area.
00:17 katsmeow-afk then please stop arguing against everything i say i need
00:18 furrywolf I've managed to make those antennas I pasted work over miles of woods. I have a very hard time believing you have enough background noise to kill them. As someone who works way too much with wifi equipment, I think that sounds like bad equipment, not noise.
00:19 furrywolf whiskey`wonka would be even better to consult, though.
00:19 katsmeow-afk orlok, here's some megawatts of uhf i can see clearly : http://maps.google.com/maps?ll=33.606756,-86.415539&spn=0.006898,0.012252&t=h&z=16
00:20 furrywolf whiskey`wonka seems to be afk right now, try bugging him tomorrow...
00:20 furrywolf he runs a large wireless isp
00:20 katsmeow-afk here's a tower with horns on it : http://maps.google.com/maps?ll=33.611671,-86.411789&spn=0.001724,0.003063&t=h&z=18
00:20 furrywolf and knows too much about making it work.
00:22 katsmeow-afk furry, i want to standardise a system somewhere on the lower vhf tv bands up to the top of fm broadcast band, so i can link stufff all over my place, or away from the boat, easily and cheaply
00:23 katsmeow-afk i would say here't eh rest of the horns, but they seem to have blurred them out : http://maps.google.com/maps?ll=33.6199,-86.400046&spn=0.001724,0.003063&t=h&z=18
00:23 furrywolf designing your own as opposed to using off-the-shelf hardware will not be easy.
00:23 katsmeow-afk just shoot me now
00:24 katsmeow-afk http://maps.google.com/maps?ll=33.624483,-86.399698&spn=0.001724,0.003063&t=h&z=18
00:24 katsmeow-afk the ridge over there is littered with towers
00:25 furrywolf so are the ridges here, and everywhere else - and wifi works. if there's really enough noise to prevent close-range wifi, you need to have a talk with the fcc.
00:25 katsmeow-afk yeas, i really need to get more government attetion here
00:25 katsmeow-afk last i spoke witht he fcc, they said they don't chace down interferrence any more
00:26 katsmeow-afk fuck
00:26 orlok too worried about nipples on tv apparently
00:26 rue_mohr damn I missed too much and I cant scroll up
00:26 furrywolf shift-pgup doesn't work?
00:27 rue_mohr not on the text irc client
00:27 furrywolf have you tried?
00:27 rue_mohr yea, it does nothing
00:28 furrywolf odd. it's a feature of the linux terminal, not the client, and works with everything...
00:30 rue_mohr must be cause of ncurses magick
00:31 rue_mohr building a reprap is fun
00:31 rue_mohr after the first one it wont be so damned expensive either
00:32 rue_mohr kat left :(
00:33 furrywolf kat's problem is far more likely to be hardware or windows than actual interference, and while she's very tallented, engineering an entire wireless network system of her own is unlikely to be practical.
00:33 furrywolf and it's my problem for point this out.
00:33 furrywolf bleh.
00:33 rue_mohr whats she want to do with wireless?
00:33 furrywolf <katsmeow-afk> furry, i want to standardise a system somewhere on the lower vhf tv bands up to the top of fm broadcast band, so i can link stufff all over my place, or away from the boat, easily and cheaply
00:33 rue_mohr on a good day even ideal wireless is crap
00:34 furrywolf <katsmeow-afk> i have 300 cable boxes, surely i can build some sorta rf link
00:34 rue_mohr hmm, sounds like my idea for ultra wide band fm
00:34 rue_mohr modulate over a range of like 30Mhz
00:36 rue_mohr the modulation clips over so many other channels, nobody notices
00:37 rue_mohr yes, building that reprap is good
00:37 rue_mohr side note, it takes 18' of threaded rod for the frame
00:37 furrywolf building a reprap is a lot easier than engineering a wireless networking system from scratch.
00:38 rue_mohr +-
00:38 rue_mohr software defined radio is taking leaps and bounds
00:39 furrywolf at any useful data rate, it becomes hard.
00:39 furrywolf or any useful range.
00:39 furrywolf the idea that wifi won't work because of interference requires some very hard numbers to back it up, as such noise is unheard of.
00:39 furrywolf crap hardware and software, however, is quite common.
00:42 rue_mohr wifi dosn't need noise to not work
00:42 rue_mohr wifi is ****
00:42 rue_mohr so, there is a peice of software I havn't written that I needed again today
00:42 rue_mohr so I been thinking about it more
00:42 orlok wifi is like the whole cable being broken
00:43 rue_mohr :)
00:43 rue_mohr the idea is that you enter into a program how many of what lengths of material you have, and what lengths you need
00:43 furrywolf and for her idea of lightning isolation, a few ebay switches and a short fiber run will take a week and be gauranteed to work, while engineering her own system will take months and probably not work.
00:43 furrywolf and it's my problem for pointing this out.
00:43 furrywolf fuck it.
00:43 rue_mohr the program tells you how to cut which of your peices to best utilize it
00:43 furrywolf every time I try to help people, I get crap.
00:44 furrywolf so no more helping people.
00:44 rue_mohr heh
00:44 rue_mohr having an off day?
00:44 rue_mohr hmm, describing it helped
00:44 rue_mohr its just two arrays
00:45 furrywolf my day was fine until I tried to help kat.
00:45 rue_mohr and I just need to itterate all possable combinations and grade based on the amount of wasted material
00:45 rue_mohr she will be ok
00:46 rue_mohr one array for supply material
00:46 rue_mohr and array for result lenths
00:46 rue_mohr hmm
00:46 rue_mohr but the waste will always technically be the same
00:47 rue_mohr so you have to grade the results on how many peices of supply material you didn't need?
00:48 furrywolf or minimize the number of pieces you do need.
00:48 rue_mohr of supply material, yes
00:48 rue_mohr so... how do you quantitize that...
00:49 rue_mohr I suppose there could be an array representing the scrap bits from each supply piece
00:49 rue_mohr where 100% means it wasn't used
00:50 rue_mohr would also need an array for representing the result piece was made
00:50 furrywolf seems easy enough to me. start adding up desired lengths in various orders, and every time you exceed the length of a piece, go on to the next one. if at any point you end up with more pieces than a previous result found, backtrack.
00:51 rue_mohr so you mean successivly make the best fits you can
00:51 rue_mohr what if earlier good fits screw up later good fits?
00:51 rue_mohr exmple
00:52 rue_mohr supply 10 unit pieces
00:52 rue_mohr hmm
00:52 orlok doesnt this get into the whole P/NP thing?
00:52 rue_mohr result in 2 3unit peices,
00:52 rue_mohr 5 5unit peices
00:52 rue_mohr 3 7 unit peices
00:52 orlok though at least theres an upper limit on the "best" solution
00:53 rue_mohr hmm
00:53 rue_mohr I think that solution is too easy
00:53 orlok is there any way to do it other that brute force and comparing?
00:54 rue_mohr dunno
00:54 furrywolf it has a very long runtime in some circumstances, but can mostly be avoided with good coding.
00:54 rue_mohr its been on my mind for over 6 years
00:54 rue_mohr the rods I have for the reprap are 3'
00:54 furrywolf also, for reasonable input sizes, even pure brute force would be a fraction of a second.
00:55 orlok rue_mohr: doesnt it just end up being another variation of the travelling salesman problem?
00:55 rue_mohr I need someting like 3 440mm peices, 6 390mm peices and 4 290mm peices
00:56 rue_mohr I made 390+440 of 3 3' peices
00:56 rue_mohr with about 10cm left over each
00:56 furrywolf the trivial solution would be to try all permutations and see how many pieces each one uses
00:56 rue_mohr its a verry finite solution set
00:56 orlok furrywolf: thats the basis of P/NP isnt it?
00:57 furrywolf better solutions would involve not solving redundant checks, that is, recognizing you're in the same place as an earlier configuration.
00:58 furrywolf orlok: I don't think so, as this problem can't be verified in polynomial time either.
00:58 furrywolf so it's plain ol NP.
00:58 orlok yup
00:58 rue_mohr it gets harder if the supply peices are all different lengths
00:59 rue_mohr which is the case for me most of the time
00:59 orlok rue_mohr: you know the travelling salesman problem?
00:59 rue_mohr I'v heard of it, but cant recall, something about travel distance
01:00 orlok http://en.wikipedia.org/wiki/Travelling_salesman_problem
01:00 rue_mohr uh, I'm on a text console caue my X is fubard
01:00 furrywolf lynx
01:01 orlok heh, thats ok - the only picture is a portrait of some irish mathemetician
01:01 rue_mohr sorry, I'm gonna just click the url with the moouse?
01:01 rue_mohr :) gnight
01:05 furrywolf bbl, wolfy bedtime
08:53 rue_mohr damn ebay screwed me up
08:53 rue_mohr if they cant find any results for your search criteria, they CHANGE THE CRITERIA and give you results on that
08:54 rue_mohr so last nights $1 has screwed up shipping
08:54 rue_mohr must get this machine going again
19:35 e_shop opens a pac
19:36 rue_shop ooo its a max7219
20:02 rue_shop Triffid_Hunter, there are two peice belt guides that are supposed to fit on the bearings,
20:02 rue_shop are the @#$%$#%^@ things supposed to clip togethor?
20:11 rue_shop3 http://reprap.org/wiki/Prusa_Build_Manual
20:40 rue_shop haha! I just got two more packages in the mail!
23:52 furrywolf just put new spark plugs in my truck... it only needed one, though, looking at the ones I pulled out. heh.
23:52 Tom_itx better check the wire and cap on that one then
23:53 katsmeow-afk do a tip-to-tip conductivity, my 280zx burned plugs open, electrically speaking
23:54 furrywolf it's not burnt. it's covered in baked-on oil.
23:55 furrywolf the #1 cylinder always oil fouls plugs.
23:55 katsmeow-afk sorry, i cannot see it from this angle
23:55 furrywolf needs valve guides, I think.
23:56 furrywolf sometimes it starts making valvetrain noise, too...
23:57 furrywolf the good news, is the truck idles properly, which it hasn't done in literally years.
23:57 furrywolf it really liked having the needle seat cleaned.
23:57 furrywolf before, it'd idle for ~30 seconds, the carb would start dumping, and it'd stall.
23:59 katsmeow-afk valve guides can be a pricey bit of work, best done with the heads in a mill, but valve guide seals/booties is easy if you can get the springs off and not let the engine swallow the valve