#robotics Logs

Apr 27 2013

00:32 yahweh Can I get away with 2.5v or will that not reach threshold?
00:45 Triffid_Hunter won't reach threshold
00:45 Triffid_Hunter need a booster for that
00:46 yahweh wretched
00:47 yahweh There is literally (not the figurative literally, I literally mean literally) no room for anything inside.
00:47 Triffid_Hunter have to be green or red then
00:47 yahweh You ruined my day
00:48 Triffid_Hunter me? nope, laws of physics
00:48 yahweh Okay, how big would a booster be?
00:48 Triffid_Hunter to make a blue photon, the electron has to drop down a 3v gradient
00:49 Triffid_Hunter yahweh: http://i280.photobucket.com/albums/kk164/bigclivedotcom/joule8.jpg
00:50 yahweh Hmmm, that's a lot smaller then I expected.
00:50 yahweh Maybe it can be done.
00:50 yahweh Thank you good sir, I adjourn to the wilds of the internet.
00:50 Triffid_Hunter ;)
00:51 Triffid_Hunter yahweh: ps: if you add a capacitor to ground between resistor and feedback coil it runs a lot better
01:00 Facepainter Does anyone have good sources of information on hydraulics-based robotic arms?
01:04 rue_shop2 Tom_itx, I made a molex tool on the lathe and its sweeeet
01:12 delinquentme good place to get pendulum bearings?
01:13 rue_shop2 bcbearing.com
01:15 delinquentme or maybe theres a better way to mount this platform
01:15 delinquentme http://www.youtube.com/watch?v=NFlar4PdZ0A
01:16 delinquentme trying to recreate that movement ... and need something between the portion which moves at the top.. and the base
01:20 delinquentme no matches on the search
01:22 rue_shop2 its just syncronized cranks
01:26 e_shop2 turns the music up to "can't th
01:30 yahweh Hey Rue
01:31 yahweh What should I grab from where for this booster Triffid recommended?
01:32 yahweh Will main and Lee's have everything I need?
01:32 Triffid_Hunter never heard of either of those
01:33 Triffid_Hunter you need a npn transistor, some magnet wire (motors from toys probably easiest place to find), a ferrite bobbin of some sort, a 100r-1k resistor.. add a 10nF capacitor if you can find one
01:45 yahweh Thanks again Triffid
01:46 yahweh The places I mentioned are electronics stores in Vancouver.
01:51 rue_shop2 hey
01:51 yahweh Hey Rue
01:51 rue_shop2 what booster?
01:51 yahweh How you doin'?
01:51 yahweh I can't find a 2.5v blue LED anywhere.
01:51 rue_shop2 playin in the shop
01:52 rue_shop2 uh
01:52 yahweh But the circuits source voltage is capped at 2.5v
01:52 rue_shop2 what you trying to make
01:52 yahweh Just want to replace a red LED on a headphone amp
01:52 rue_shop2 your trying to run a blue led on two NiMh batteries?
01:53 yahweh Can't stand red LEDs
01:53 yahweh pretty much
01:53 rue_shop2 did you try to just replace the led?
01:53 yahweh Won't it not reach threashold?
01:53 rue_shop2 its quite likley to just work
01:53 rue_shop2 how many of what battery are in it
01:54 yahweh 2xAA rechargeables.
01:54 rue_shop2 3V, k
01:54 rue_shop2 let me see what a blue led actually drops
01:54 yahweh More like 2.4-5 no?
01:54 Triffid_Hunter nope, rechargeables give 1.2v/cell nominal
01:54 Triffid_Hunter so can only count on 2v being available
01:54 Rif ABOUT 3.4 NORMALLY, BUT 3V WILL LIGHT IT
01:54 Rif yeah right
01:55 yahweh God damn brother and his god damn porn killing my internet.
01:56 rue_shop2 it drops 2.5V, runs fine from a 3V supply with even a 1K bias led
01:56 rue_shop2 do some site redirection on the router :)
01:57 rue_shop2 yahweh, so the answer is to just replace the led
01:57 yahweh I just cut his internet entirely.
01:57 yahweh Alright, worth a shot.
01:57 rue_shop2 want a 10mbit HUB ?
01:57 rue_shop2 ;)
01:57 yahweh It's got a life time warrenty even if I fail at modding it. XD
01:58 yahweh hub?
01:58 yahweh no thanks
01:58 rue_shop2 for the line to your brother
01:58 yahweh XD
01:58 yahweh Maybe hahaha
01:58 rue_shop2 just run it thru that
01:58 yahweh I haven't seen anyone use a hub since highschool.
01:59 rue_shop2 they are good for network snooping
01:59 yahweh Oh I bet
01:59 yahweh I don't want to know what he's downloading though.
01:59 rue_shop2 no, but they can only pass info in one dir at a time, so its slow
02:00 yahweh I know, great for internet killing.
02:00 yahweh I find the idea quite amusing.
02:00 yahweh I just block his ip when this happens though, it works.
02:03 Triffid_Hunter need a server with proper ingress queueing
02:04 Triffid_Hunter last time I was in a sharehouse I set one up, was awesome.. anytime someone started a game, all the torrents would drop to allow it enough bandwidth
02:04 yahweh Doesn't take much torrent at all to murder ping
02:05 yahweh I just turn off his internet when I want to game, it just plain works.
05:46 delinquentme http://www.shapeways.com/model/779258/triple-gear.html
05:46 delinquentme thought you guys would like this
05:46 delinquentme seems like a really novel concept for a thrust bearing
14:48 rue_house http://www.youtube.com/watch?v=TDiIOTjyHzU
14:50 rue_house http://www.youtube.com/watch?feature=player_embedded&v=_d0LfkIut2M
14:51 yahweh THAT'T AWESOME!
15:19 rue_house http://www.youtube.com/watch?v=4YZeX8ti7Io
15:20 rue_house just imagine what people could be doing with mechano if they had been willing to even enter the elecronics age
15:20 rue_house meccano
15:29 GargantuaSauce i find meccano pretty unwieldy
15:29 GargantuaSauce it's quite heavy, you'd need some serious motors to do anything significantly mechatronic
15:33 rue_house heh
15:34 rue_house the number of things people got around to make that stuff out of lego makes that problem pale in comparison
15:34 GargantuaSauce i guess
15:35 Sorcerer1 yeah, it would be awesome if there was something sturdy around to build stuff out of
15:35 Sorcerer1 that did not require a bunch of powertools
15:37 GargantuaSauce i need to get my printer working again, pla is pretty damn strong for its weight
16:37 yahweh What are you up to tomorrow Rue?
17:25 MrCurious fringe is one twisted series :)
18:05 Curious wonders how long i have to stare at neural network docs before it will c
18:07 GargantuaSauce what are you going to be doing
18:09 MrCurious working out what they are useful for
18:11 GargantuaSauce i've worked with feedforward networks taught using backpropagation
18:11 MrCurious http://image.diku.dk/shark/sphinx_pages/build/html/rest_sources/tutorials/algorithms/ffnet.html
18:11 GargantuaSauce they're good for making simple decisions about fuzzy data
18:11 MrCurious trying to work out if i can easily use it for face recognition
18:12 GargantuaSauce with lots of inputs and few outputs
18:12 MrCurious wonder if it would be good for classifying lego bricks
18:12 MrCurious and a big fat hidden layer
18:12 GargantuaSauce facial recognition is a big big hard problem
18:13 GargantuaSauce the hard part about the whole process is defining a model for the inputs really
18:15 GargantuaSauce you could probably classify lego bricks fairly easily if you had a very controlled environment for the sensors involved
18:16 GargantuaSauce ie using vision, you have a fixed position and orientation for the piece relative to the camera
18:16 GargantuaSauce and controlled lighting
18:17 GargantuaSauce i think xor is a terrible example because it's the pinnacle of inefficiency for an nn to do it
18:18 GargantuaSauce the whole point of an nn is to have the system build a model correlating its inputs and outputs on its own, one that is not a simple analytic solution
18:21 MrCurious yup
18:21 MrCurious 20 some years back, i did some BP nn work
18:22 MrCurious backwards propigating
18:37 MrCurious guessing before using a neural network, probably will want to convert the images to a edge detection B&W line art
18:38 GargantuaSauce perhaps
18:38 GargantuaSauce you'll want to experiment with different sorts of inputs
18:40 GargantuaSauce things like gaussian sampling with different scales, or even move away from a per-pixel scheme to sampling along randomly placed lines
18:42 GargantuaSauce i've read that our optic nerves act like a repeated laplacian transform on the retinal image and a lot of compression is afforded that way
22:48 MrCurious 180Ah 3S lipo array soldered and working