#robotics Logs
Mar 11 2013
#robotics Calendar
00:07 rue_house I need longer runs of open time, I cant get anyting done with such msall time slives
00:11 Rif well i wasted the weekend doing about an hours coding that took me 48
00:19 rue_house did you get hat last hello work working
00:19 rue_house ?
00:23 Rif i think so yep
00:24 Rif rue i wanna sense current sand voltage tonight, so just need a few 1% resistors and a large low ohm for the current?
00:25 GargantuaSauce you'll want an amplifier for the current shunt
00:26 GargantuaSauce (and a very low resistance shunt)
00:27 QuantumParadox Hey guys, anyone want to help a Rochester insitute of technology Robotics Club student program a little robot?
00:28 Rif lol
00:28 Rif GargantuaSauce a 3W 0.01R
00:28 Rif QuantumParadox no one will do it for you, but we will try and assist when you have issues
00:30 QuantumParadox No, I am not asking for anyone to do this for me. i love doing this. This is a hobbie I started and I am trying to find people with my interest. infact, I worked on robonaut when i did my NASA intern. I did coding for the upper body.
00:30 GargantuaSauce so that'll blow up at 17A or so
00:30 GargantuaSauce at which current the voltage across it will be 0.17 of course
00:30 GargantuaSauce hence why you'll want an amplifier
00:31 Rif GargantuaSauce i reckon about 10A will be max to test
00:31 GargantuaSauce yeah that's a sane cap
00:32 Rif so an opamp?
00:32 GargantuaSauce yeah
00:33 GargantuaSauce i am too analoguely challenged to walk you through it but you want to set a gain such that the maximum voltage across the shunt becomes the reference voltage of the mcu's adc
00:34 GargantuaSauce to maximize the resolution of your measurement
00:34 Rif yep
03:01 RifRaf getting linear results from voltage divider with max output 1.1v? should i aim for 5v or vcc?
03:01 RifRaf however am not getting linear results measuring voltages arcoss 0.01R resistor to get current, is this to be expected?
03:02 theBear what is vcc ?
03:02 theBear and no it's not to be expected
03:02 RifRaf the voltage the avr is getting, 5v
03:03 theBear lol, "should i aim for 5v or 5v" ....
03:03 RifRaf yes sir, instead of 1.1V
03:03 theBear so erm, is it linear up to a point with the current ? maybe you overheating the thing, tho it did say 20a or something
03:03 RifRaf something i saw at work was using 1.1V for the adc
03:03 RifRaf i got other resistors to make it max 5v
03:04 RifRaf no never linera
03:04 theBear oh, so you CAN run an avr adc reference that low ?
03:04 theBear never linear ? that's err, wrong, how you multiplying it ?
03:04 RifRaf some eg, 1.6mV@100ma , 2.4mV@200ma
03:04 theBear oh, you measuring that with meter or avr ?
03:04 RifRaf 9.8mV@1000ma, 11.9mV at 1.2A
03:04 RifRaf meter
03:05 RifRaf controlled current source and multimeter for voltage
03:05 theBear you got dirty bananas, to measure those kinda voltages accurately they need to be REAL clean
03:05 RifRaf using a smart charger for the current source, thats charging batteries, is all digital and trustworthy
03:05 theBear little contact cleaner and a wiggle should fix it up, go to low resistance range and aim for 0.00000000
03:05 RifRaf soldered connections
03:06 theBear your meter probes are soldered on ?
03:06 RifRaf wellno, but pressed hard up against the breadboard wires soldered to the resistor
03:06 theBear and you soldered to the right spot on the shunt, right below the flanges (tho that should only effect accuracy, not linearity)
03:07 theBear i said the bananas, not the tips
03:07 RifRaf i am holding them on with force
03:07 theBear stick it in resistance, touch the probes together, notice how you don't get even close to 0ohm
03:07 RifRaf oh the other end, hrm ok, its a new meter though
03:07 theBear doesn't matter, they need at least a wiggle every few days to work on super low ranges
03:08 RifRaf ok, so a wiggle and test low resistance, across resistor or probes together?
03:08 theBear probes together
03:08 RifRaf k brb
03:08 theBear eliminates all tolerance
03:08 Jak_o_Shadows1 Wish I hadn't chucked out the heating section of that hair-drier 4 years ago.
03:09 theBear Jak_o_Shadows1, you can get similar things for a few bucks as electric-kettle spareparts
03:09 RifRaf ok pre wiggle is 0.5R
03:09 theBear also usually 4ohms or very close which is handy for certain purposes
03:09 RifRaf heh post wiggle is 0.6r
03:09 theBear lol, got contact cleaner ?
03:09 RifRaf ok maybe this $5 meter not good enough for this
03:10 Jak_o_Shadows1 theBear: Yeah, or i could get 4m from jaycar for $5. Problem is, i'd use more in petrol driving there
03:10 theBear oh, probly not, you want a $35 one :)
03:10 theBear Jak_o_Shadows1, that is a problem
03:10 RifRaf will use the real one, it has clips instead of probes as well
03:10 theBear i wish i had $5, i could eat something :(
03:11 theBear i can't compliment the qm153X range enough for reference, you both should know what that means
03:11 theBear everyone else will be confused as hell
03:11 RifRaf that bad off? well appears the cheap meter does not measure below 0.1R
03:11 theBear and by for reference, i mean for the record, i wouldn't use one as a real reference :)
03:11 k_o_Shadows1 is conf
03:12 theBear .1 isn't TOO bad, but if it won't go lower it's not great, below 100mv or 1ohm is touchy for any meter
03:12 theBear Jak_o_Shadows1, jaycar rebrand part nos for their sinometer meters
03:12 RifRaf no it only gets to 0.5R, this meter is going to .3R
03:13 theBear i been using the qm153? since the late 90s for all kinds of things, gone past 1000v, measured incredibly low stuff, they're always rock solid
03:13 theBear plus VERY reasonably priced
03:13 RifRaf its a q1585 automotive one
03:13 Jak_o_Shadows1 I have a cheap dick smith one, and an even cheaper non-DSE branded dick smith one
03:13 RifRaf ok will get some new results
03:13 theBear hmm, i never played with that one, but often automotive exchange accuracy for price and/or high current ranges
03:14 theBear not like you ever care about <1r in automotive, generally only beep or <1meg (carbon sparkplug leads), and 12v or 0v :)
03:14 RifRaf well only other one i have working, lets see what the results are like
03:14 theBear maybe a few hundred r if you doing coils/alternator rebuilds
03:15 theBear but a shunt should be linear, v = r * i guarantees it, and that one made a point of saying it was relatively flat regardless of temp
03:16 theBear i suppose it's not impossible that a 'smart charger' cuts some corners... not like 50mA error in current setting is the end of the world
03:17 theBear if you got multiple meters and one of them has a good fuse it's worth comparing actual current vs shunt voltage.. oooh, also remember that a 'real' current set will stay right, but one expecting a certain voltage (ie. a battery) might have problems with the shunt dropping some voltage
03:19 theBear i wonder how accurate popeye is.... "good sir, if you give me a hamburger today i would glady pay you on pension day"
03:21 theBear oooh, and also also remember that a charger generally pulses/uses VERY low freq pwm, cos it's better for batteries, but might confuse meters
03:21 theBear a big cap across the shunt should prove/disprove that
03:22 theBear and i mean BIG
03:23 RifRaf ok looking a bit better
03:23 RifRaf still off on low currents
03:25 RifRaf 1.6mV@100mA , 8.5mV@1A , 17.9mV@2A , 29mV@3A
03:26 theBear hmmmm.... should be better than that, while we at it, you measured the shunt ? sounds like it might be a little low in value
03:26 theBear but i'm really starting to lean towards the charger being inaccurate
03:27 RifRaf cannot measue 0.01R
03:27 theBear i wonder what a 8 bit table would look like between 0 and the max current the charger provides....
03:27 RifRaf have to trust jaycar
03:27 theBear good point
03:27 theBear what is the max the charger does ?
03:27 RifRaf 5A
03:27 zap0 jaycar is run by morons
03:27 theBear obviously
03:28 RifRaf am measure the current fed to charger, thats where the problem is
03:28 RifRaf need to measure the regulated output
03:28 theBear huh ? current fed TO the charger ?
03:28 theBear that will never work
03:28 RifRaf yeah i just realised
03:28 RifRaf is dc to dc charger, i am measuring the 12V in current
03:28 RifRaf brb
03:28 theBear for reference if the charger uses 8bits to set current, it can't get closer than 19.5mA to target current
03:29 theBear and remember what i said about the pulsing/cap on shunt
03:29 RifRaf yep ok, will try this first though
03:30 RifRaf i am a bit silly at times, this was just another one
03:32 RifRaf best to measure current on negative or no matter?
03:33 theBear no matter, BUT since you are planning to adc it, you want referenced to 0
03:34 RifRaf true
03:34 theBear remember some-dude-i-forgot-the-name's law, current is the same at all points in a (simple) circuit
03:36 Jak_o_Shadows1 Ohm or kirchoff?
03:36 theBear kirchoff 1
03:36 theBear !
03:38 RifRaf ok 0mV at 0mA , much better start
03:39 RifRaf ooh getting better figures now
03:40 RifRaf too nice
03:40 theBear hooray
03:42 RifRaf 1mV@100mA, 10mV@1A, 19.9mV@2A, 29.6mV@3A, 39.4mV@4A
03:42 RifRaf almost perfectly linear and easy to use values
03:43 RifRaf ok so max would be 200mV @ 20A , so should i use an opamp now for gain?
03:46 RifRaf got a couple of lm741 cause too hard to find stuff here still
03:52 RifRaf should be able to get gain of 26% with a 10k and 390r
03:52 RifRaf 26*
04:05 theBear sounds about right
04:05 theBear tho you might pick a power of 2 to make maths easier/quicker
04:05 theBear like err, 16 or 32
04:16 RifRaf well i cannot believe how many time i can hook an opamp and 2 resistors up wrong
04:16 RifRaf am sure i killed it because now that i 'think' its correct its still not working
04:18 RifRaf will start again
04:18 RifRaf theBear i just trusted this calc to check the values i had handy
04:18 RifRaf http://www.petervis.com/electronics%20guides/741%20Op%20Amp/741%20Op%20Amp%20Gain%20Calculator.html
04:19 RifRaf using the second gain circuit
04:27 theBear that looks reasonable
04:27 theBear you should only kill it if you REALLY short the output or reverse the power
04:27 RifRaf dammit, does a lm741 really need 12v to run?
04:27 RifRaf maybe thats why 5v was doing nothing
04:32 theBear it's been a while, but old design, 5 probly isn't enough, also pretty sure if you wanna go down to 0 you need a negative rail by a couple volts give or take
04:33 RifRaf oh really. well thats awkward
04:33 theBear not like anyone who wasn't me could put them in anyway :)
04:33 theBear wait, wrong window
04:34 RifRaf i have a -12 0 12v supply but don't wanna add that for a simple project
04:34 theBear not great, they DO make rail2rail opamps
04:34 RifRaf ok well will test with this and get another, i just wanna test to like 10mA
04:34 theBear what powers this ? in a pinch a tiny battery will do, VERY low current, otherwise if you got some kinda ac present ANYWHERE in the psu end of things you can just run a neg diode or two and make a neg rail from that
04:35 RifRaf i have psus all over the table right now
04:35 theBear i mean target wise
04:35 RifRaf 7.2V rc battery
04:35 RifRaf cause i have heaps in all sizes
04:36 theBear also (after checking for proper isolation with a meter from output gnd to mains side) you can use pretty much any little xVDC psu as a neg rail add-on ... they're isolated, think of them like a battery
04:36 Jak_o_Shadows1 what are we actually making again?
04:36 RifRaf they work great with these cheap adjustable supplies to give the uC 5.0v
04:36 theBear and by add-on, i mean for testing/generally anywhere a whole extra wallwart doesn't suck
04:36 RifRaf but can use the 7.2 - 9v input
04:36 RifRaf Jak_o_Shadows1 am making something that may be usefull for me at work tonight
04:37 Jak_o_Shadows1 I see.
04:37 theBear oooh, if you were really sneaky (one of my new cripple-hobbies is horrible circuit hacks) you could float the whole circuit on top of a diode or 2 and a cap, forming a neg rail so long as you got a low dropout reg
04:37 RifRaf after thinking today, a led tester, for big leds and arrays
04:37 RifRaf nead to know voltage distance current and then calculate colour and brightness
04:38 RifRaf will be a cool tool
04:38 theBear on that note, you should see the irf630 i used to replace a roughly 2*3mm smd fet in a mobo fan speed control circuit :)
04:39 RifRaf then i should know enough to use it properly for a colour sensing robot
04:39 theBear dead fet, i mean, i might be crazy, but i aint crazy enough to 'mod' my pc for no good reason
04:39 RifRaf and stick one in the end of the arm i made
04:39 theBear for bonus points and 2nd hobby, i did it with 1.6mm solder, without removing the psu or mobo or cpu heatsink, and with my regular fullsize iron/tip :)
04:40 RifRaf ninja :)
04:40 Jak_o_Shadows1 Isn't .9mm solder more common lol
04:40 theBear gettin that way :)
04:40 theBear Jak_o_Shadows1, probably :)
04:41 theBear 1.6 aint bad, it's small enough to EASILY do single dip pins, and big enough that stuff like 1/4" jack plugs or large pcb pads don't suck up meters of it causing you to constantly need to unreel more
04:42 theBear actually, biggest i ever used/had for non-plumbing stuff, but also the one i've used most including literally 1000's of hours of 'professional' soldering
04:42 Jak_o_Shadows1 I've got some ancient 3mm around somewhere, never had to use it
04:42 RifRaf the solder her on table is 0.7mm, i hate it for small stuff, need to get more paste and fix rework station
04:43 theBear hmm, you can have long nicks on this network eh ....
04:43 RifRaf cannot find the tube that the rats ate
04:43 Jak_o_Shadows1 RifRaf: Did you find any dead rats?
04:43 RifRaf i killed many , but is great here at new place, never had one
04:43 theBear i loved aoyue hotair at old old work for stuff like replacing soic40's, but at new old work i did 8 and 14 pin opamps all the time and it was quicker/easier to use the regular iron and 1.6mm solder than to heatup the hotair
04:44 apimpnamedslickb awww, i can't be a pimp named slickback (yes, please say the whole thing, yes, every time !"
04:45 theBear maybe APN_Slickback ... kinda technical, and my whois info could be A Pimp Named ...
04:45 theBear my god ! i just noticed what the new name of my wifi network is :)
04:45 RifRaf yep i still use it for the soldering iron part cause it has a small tip on it, but looks dumb with all these wires hanging out of the hot air tube
04:45 RifRaf heh
04:46 theBear the very few times i turned it on, i did like the bonus smoke-sucker attachment on the iron that came with it
04:46 theBear struck me that after this many years, i should think about how much lead i breathe :)
04:47 Jak_o_Shadows1 isn't the rosin normally just as harmful?
04:48 theBear and while i don't much care for it, the suction-cup smd grabber bit was cool too
04:48 theBear Jak_o_Shadows1, probly, i was just saving words for err, grace of saying
04:53 theBear i think it's time to msg my shrink back.... it coulda been weeks if he asked if i was here.... "To quote my favourite cartoon 'I'm not dead, i'm just reaaaaal depressed' ... so err, could I please have an appointment ?" i think he'll like that
04:54 theBear doc said i should "become a yogi" .... he didn't mean literally of course, i don't think that's a real option here anyway.... but i do need to learn to be at peace with myself and those assholes around me :)
04:55 theBear i mean real doc in that one... saw him today
04:55 theBear anyone know if there are spiritual gurus in this country ?
04:56 RifRaf meh i give up on this opamp for tonight i think
04:56 theBear btw, the datasheet should tell what rails it works inside under something like maximum output voltage
04:56 RifRaf and nope, never looked for a guru sorry
04:56 theBear in the specs table
04:56 RifRaf yeah have datasheet open
04:57 theBear how do you stay sane ? surely alcahol isn't enough alone ... oh, you got family to care for....
04:57 RifRaf says +-12v
04:57 RifRaf nope no family these days, mainly good pot and fishing
04:58 theBear with the associated stuff being (+-15v supply blah blah something) ? or is there another line for same thing with min supply voltage in brackets ?
04:58 RifRaf and coststantly making things so i forget about the real world
04:58 theBear i mean junior-family, something to make it worth maintaining yourself
04:59 RifRaf well i could not find an easy answer yet, apart from wat you said and max 22V
04:59 theBear lemme look
05:00 RifRaf at the moment i get 11.76v at pin 6, with nothing on pin 3,a dn it does not change even if i give it an input
05:00 RifRaf with 12.0v supply
05:03 theBear "output voltage swing" .. doesn't have exactly, we need to extrapolate with prior knowledge... first with roughly 2kohm load, +-15v we can swing +-13 nominal, +-14v with lower load, so we think about a volt within rails, which may be err, undefined minimum....
05:03 RifRaf um does +- mean i need a -12 for - and +12 for +
05:03 RifRaf that would be nuts, but i can do it with this other module if needed
05:04 RifRaf i thought this was old school and easy to use
05:05 theBear then we look at the equiv. diagram on the next page, and think one transistor either side in pushpull on output, pulled by basically pushpull stage drivers, which means maybe 1v within rails is pretty understandable, and we see most is about 4 junctions on top of one in the input stage, so err, without doing lots of maths, you'd expect it to start working around 5v or so
05:05 theBear but only for inputs between 0+5 and outputs between -4 and 4v or so
05:06 theBear time for a nap :)
05:06 RifRaf ok, input is between .1mV and 200mV
05:06 RifRaf no worries, catch ya later
05:06 RifRaf output 0-5v hopefully
05:11 fRaf gets the engineers notebook II off the shelf, mims, circa
05:11 RifRaf this is an antique almost
05:11 RifRaf but thats a few years after i started trying this stuff
05:13 RifRaf wow this bok is so cool, but yes i need +-5 to +-18v, single using 5v to 18v
05:14 RifRaf but need negative input :/ , rue_house this is right up your alley where are you
05:26 RifRaf k i gotta find lm324 or lm3900, me starts searching
05:26 Jak_o_Shadows1 I once got a -5V linear reg off TI samples
05:27 RifRaf Jak_o_Shadows1 should have some here somewhere
05:27 RifRaf i want single supply opamp
05:27 RifRaf thats what mims says so thats what ima find
05:28 RifRaf how are digital books ever gonna get this nice old book smell
05:29 Jak_o_Shadows1 how are digital books ever gonna rot?
05:30 RifRaf when the power gets turned off
05:31 Jak_o_Shadows1 easier to copy digital books
05:31 RifRaf have you tryed living a few weeks without power, poeple go nuts
05:31 RifRaf yes, but i still like the old smell, and to think i have kept this out of not many things so many years is cool
05:32 Jak_o_Shadows1 to be honest, I mostly agree with you
05:36 RifRaf found some lm324, they seem small
05:36 RifRaf tssop package :/ no fun for breadbeard
05:38 RifRaf ok found the dips
05:57 RifRaf ok i fail, this one just gives me 0.7v out the output all the time
05:57 RifRaf will try in morn
08:49 rue_house RifRaf, amplifier for current sense?
08:50 jennie hi rue_house
08:50 rue_house hi
08:50 rue_house were you able to get the motor running?
08:55 rue_house wow, I'm glad I didn't wait more than 4 seconds for an answer to that yes-no question
08:56 rue_house :)
08:57 theBear hehe
09:58 GuShH theBear: https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-ash3/598892_250513858418683_15501932_n.jpg That's tuning at it's finest.
09:59 theBear lol, must sound awesome... at some point when yer tuning the slidey test pipe, you gotta think, surely i've gone too far and missed the mode :)
09:59 theBear welcome mr nuss
10:07 GuShH theBear: I don't like tuners
10:07 GuShH they add all this useless shit to their cars / bikes...
10:07 GuShH why not focus on the mechanical aspect, safety, engine, etc?
10:26 theBear mm, i don't believe in any silly modifications on everyday or work vehicles, racing cars are a bit different tho
10:27 GuShH well, I see it all the time
10:28 theBear yeah, me too :(
10:28 theBear i do approve of silly gearstick knobs, tiny rear-view disco balls and even silly pedals for some reason, i just think they look cool :)
10:29 GuShH Heh was looking at the "trips" section on this bike forum, they want to do a 1100KM run on those FZ16 (top speed 120KM/h if you are lucky, 100-110 is all you get usually without ruining the enigne ) that's 10 hours nonstop...
10:29 Tom_itx remember the 'foot' pedals of the 70's
10:29 theBear on the other hand, fake 100mm muffler-ends ... oh dear oh dear
10:29 Tom_itx in old vw bugs etc
10:29 GuShH LOL
10:29 theBear Tom_itx, those are among the coolest
10:29 GuShH I wouldn't add anything that wasn't functional in one way or another
10:29 theBear ooh, and TINY chain steering wheels, and window tassles done well, i'm down with that
10:30 GuShH welded chains.... what are you a punk from the 80s?
10:30 theBear but nothing that tries to make the car act or look 'better' than it is
10:30 theBear err, technically yes
10:30 theBear :)
10:30 GuShH "it actually dates way back <adjusts glasses>"
10:30 theBear hehe
10:30 Tom_itx shag carpet and tie dyed t shirts etc
10:31 theBear seriously tho, punk from the 80s
10:31 Tom_itx oh and the dark granny glasses
10:31 GuShH WITH A CANE
10:31 theBear lol, technically shirts aren't a part of the car :)
10:31 GuShH they are once she gets naked
10:31 Tom_itx it's a whole look
10:31 theBear shag carpet is a win tho, you can never go wrong with a long shag !
10:31 theBear oh wow, that wasn't meant as a double entendre, i was serious
10:32 theBear about carpet that is
10:32 GuShH shag it
10:32 theBear is that what you say when i say balls ?
10:32 theBear much more distinguished
10:33 GuShH I think I just annoyed one of those bike ricers
10:33 theBear you know, like when you bend a nail or maybe hurt your leg
10:33 GuShH I insult most of the world when that happens
10:34 theBear heh, save time if you just said shag it like GuShH does
10:34 theBear did i just blow your mind ? sorry, that kinda thing happens to me all the time
10:37 theBear awww, now i'm not in the big channel you poor bastards get all my crazy ramblings
10:39 GuShH o.o
10:39 GuShH theBear: that's good, Tom_itx won't be able to complain about MY rants only
10:39 Tom_itx http://tom-itx.dyndns.org:81/~webpage/women_vs_men/whymendie_index.php
10:42 theBear very nice
11:03 GuShH Add a harness and I'd do that.
11:03 GuShH I do all kinds of crazy stuff with a harness.
11:04 theBear i only do crazy things OR sensible things without a harness, they're so damned annoying and restrictive, plus, i'm kinda ambivolent about the idea of instant accidental death these days
11:04 GuShH ...?
11:04 GuShH mine is not that restrictive
11:04 theBear i mean being fixed to something
11:04 GuShH and it grabs your balls constantly, like women do.
11:05 theBear they sure do <wink>
11:05 GuShH Well sir, you ought to be fixed to something otherwise the harness is just for show
11:05 theBear ever been on a wobbly old badly maintained tall-a-scope ? i loved doing that, i dreamed about what might happen if it fell over with me up top, or the basket just fell off
11:05 GuShH my last anchoring point was not exactly the safest. two water pipes from a radiator
11:05 theBear well obviously, this is why i don't use them
11:06 GuShH it would've stopped me from slipping down the roof though.
11:06 GuShH Had to go out the window and pop out the other side to fix some tiles
11:06 GuShH slips != free fall
11:07 GuShH Plus my harness is only rated for one free fall, specially the life cord
11:07 theBear meh, freefall is the joy before the darkness
11:07 theBear that feeling when you know yer gonna die... i only had it twice personally
11:08 theBear and now, it's nap time for bears
11:08 theBear :)
11:08 theBear sweet dreams gentlemen
11:09 ShH w
11:09 GuShH I never had a free fall that was over 5-6 meters
11:10 GuShH The worst one was assisted by a branch. I would do that again!
13:43 ganzuul :D
13:43 home hey
13:43 ganzuul Hi.
13:43 home so I am going to disamble this little robot
13:43 home gonna take pics
13:44 home I have to reassemble it also
13:44 home do you guys have any advice or precautions when disassembling and reassembling something?
13:44 home i.e. little robot
13:44 ganzuul I made my smartphone send its sensor data to a web browser using node.js as an intermediary. I want to be on the winning side for the robot rvolution. =D
13:47 ganzuul home: Maybe take pics of your progress if you are unlikely to remember which way to put it back together.
13:52 home I want to use an android phones accelerometer and gyro on my ardu robot
13:52 home that I have so far
14:06 ganzuul For android, phonegap/cordova may be the easiest solution to get data out of the phone. Right now however there doesn't appear to be gyro support.
14:07 home I see
14:07 home I just want it to give me the info via serial from the usb port
14:07 ganzuul My phone is a Nokia N8, Symbian, which was abandoned as a platform recently. I had to mash some example code together in C++ to get it working.
14:08 ganzuul Hm... I that case you are probably looking at the plaform's hardware language of choise.
14:10 ganzuul There was a sensor fusion demo for android though, so you may perhaps be able to re-use that code if it's open.
14:18 home what does EXT1 and EXT2 mean..hmm
14:18 home ganzuul: it should be doable
14:21 ganzuul Takes a little elbow grease, and lots of coffee. =)
14:21 home urgh I hate greese
14:23 RifRaf rue_house yep, amp for current sence
14:24 home hmm 2 limit switches and 1 ultrasonic removed so far
15:02 ganzuul hmm... got the magnetometer working the same way as the accelerometer... but not the gyro. Very odd.
15:06 ganzuul huh...! it has a rotation sensor instead.
15:19 GuShH huh huh
15:19 ganzuul hurr
15:22 RifRaf ok op amp gain calculated at 84, am getting from 50x at low input like 4mV upto 81x with 50mV input
15:23 RifRaf below 4mV drops off fast, like 3.5X gain at 1.1mv, but i need it to work at low inputs, wat the fix?
15:28 ganzuul Just guessing based on schooling from a long time ago; you've got some component like a coil with a high resistance of size proportional to the 'knee' of a graph of that gain.
15:29 ganzuul So it would always be eating some current, but it's not noticable until you get to low voltages.
15:29 RifRaf maybe, i thin that i need to shift ground lower than 0 to be able to measure close to 0
15:29 ganzuul Also, got all three sensors working in parallel. \o/
15:30 ikrima hey, i have a noob problem that i've been trying to google with no luck
15:30 ikrima i'm trying to power the motor from a battery drill bit with a wall wart
15:30 ganzuul Shoot. We're all noobs shere.
15:30 ganzuul (actually I have no idea, I just dropped in some hours ago)
15:31 ikrima haha, nice
15:31 ikrima the battery's 12 volts so i figured a 12 volt adapter should be fine
15:31 ikrima but then I read about the stall current of motors can be up to 25 A
15:31 ikrima so now I'm puzzled b/c I can't imagine the battery providing that much current
15:31 RifRaf shoot, gonna be late for work, better run
15:31 ganzuul Batteries can give off crazy high currents.
15:32 ikrima really? hmm, damn
15:32 ganzuul http://youtu.be/8tHJ0NSjZnM?t=3m
15:33 ganzuul Welding with car batteries. <3
15:34 ganzuul By the way, this is why you never, EVER short batteries.
15:34 GargantuaSauce what if you want to weld something
15:34 ganzuul If they're lead-acid they asplode with acid and led in your face.
15:34 ganzuul GargantuaSauce: Then try not to weld your face.
15:35 GargantuaSauce safety is such a buzzkill
15:36 ganzuul lol
15:36 GargantuaSauce you are probably looking for something like thi http://dx.com/p/125352 ikrima
15:36 ganzuul The video says you should throw a battery over them, to keep sparks from igniting the highly explosive HHO gas that can be generated.
15:37 ganzuul ~blanket over the batteries
15:37 GargantuaSauce check fleabay too, you'll probably find a better deal
15:37 GargantuaSauce yes some nice thermal insulation to keep that precious heat from escaping, there's a good idea :V
15:38 ganzuul It could contain the explosion. \o/
15:45 home wtf
15:45 ikrima GargantuaSauce, that looks exactly like what i need
15:45 ikrima GargantuaSauce, even more noob question…how do I plug it into the wall?
15:46 GargantuaSauce very carefully
15:46 ganzuul Yeah... Check your circuit breakers beforehand. Make sure no one has tampered with them.
15:46 GargantuaSauce personally i cut up power cords for other things and just screw them right onto the terminals
15:47 GargantuaSauce but if you wanted to get all fancy schmancy and safe and stuff you'd want to make an enclosure with a socket
15:49 ikrima nice
15:50 ikrima will definitely need that as i'm sure i will accidentally step onto the powersupply on the shoot day
15:50 GargantuaSauce if you just do the former, you should at least cover the mains terminals with something that is an electrical insulator
15:50 GargantuaSauce so that a dropped staple or something can't short it out
15:51 GargantuaSauce (not that that wouldn't still be an issue with the actual gaps in the case)
15:51 ikrima gotcha
15:51 ikrima would another option be to buy a laptop powersupply and cut that?
15:52 ikrima hmm, n/m. I don't think they provide enough current
15:53 GargantuaSauce a big one would, but most are of a notably higher voltage
15:54 GargantuaSauce you could also potentially use a pc's power supply if its 12v rail has enough current capacity but that is notably more complicated
15:54 ikrima it blows my mind that a handheld battery operated drill can draw +20 amps of current
15:54 GargantuaSauce it's just for a fraction of a second
15:55 ikrima does that mean I can get by without having a super highly rated power supply?
15:56 GargantuaSauce potentially but i wouldn't bet on it
15:56 ikrima gotcha
15:56 GargantuaSauce basically when you draw too much current the voltage will start to drop
15:56 ganzuul A bulky capacitor might do it, but you'd need a circuit to charge it.
15:56 GargantuaSauce many of them have protection circuitry that makes it automatically shut down for obvious reasons
15:58 GargantuaSauce even if the psu doesn't complain too hard under those circumstances, it's a question of what the drill does
15:58 ikrima gotcha
15:58 home heh
15:59 GargantuaSauce because power drills are not just a switch and a motor, they actually have electronic motor controllers i believe
15:59 ganzuul A desktop computer's PSU gives 12V...
15:59 home I need to get better electrical knowledge XD
15:59 home for a cs
16:00 ikrima GargantuaSauce, well, we're separating out the motor
16:00 ikrima i have a motor controller attached to an arduino
16:00 GargantuaSauce you should use the drill's motor controller
16:00 GargantuaSauce replace the switch on it with something you control with the microcontroller if need be
16:01 ikrima i tried looking at it, but it was too complicated for me
16:04 home oh god
16:22 ganzuul home: http://ros.org/wiki/android_sensors_driver
16:26 home ganzuul: interesting
16:28 ganzuul *nod* and bedtime...
19:00 rue_house RifRaf, you cant just use the math on those, the dc offsets are a mess
19:01 rue_house amplifiers dont like going all the way down to 0 or up to vcc on the inputs
19:07 rue_house wow, almost 1 second ping to ebay
20:03 Tom_itx rue_house
20:03 Tom_itx you can load 2 hex files into an avr
20:08 RifRaf why?
20:10 Tom_itx save time
20:10 Tom_itx i loaded a bootloader and instead of using it to load the hex to run i uploaded it via ISP as well
20:10 Tom_itx and i wanted to see if it could be done
20:25 rue_house hu?
20:28 Tom_itx works as long as you turn off erase before write
20:29 Tom_itx doesn't matter the order either
20:29 Tom_itx i tried it both ways and it works either way
20:29 Tom_itx loading the hex first or the bootloader first
20:46 rue_house I'm go work on the boiler..
20:52 Guest63474 rue_house: what's wrong with it?}
22:02 rue_house I took it all apart for service
22:03 rue_house fixed the blower bearing, opened up a restruction in the duct, and removed the rocks from the burn-grate
22:11 ch1p5et join #electronics
22:29 rue_house no!
22:29 rue_house electronics is full of trolls and admins that support the trolls
22:30 rue_house I nolonger want any part of it
22:35 MrCurious http://www.mpja.com/Stepper-Motor-Assembly-NEMA-23-53V/productinfo/17461%20MS/
22:35 MrCurious very nice stepper with matching gears
22:35 Tom_itx rue_house, what is considered a 'slow' crystal when you are setting fuse bits?
22:38 GargantuaSauce holy shit that's cheap
22:38 GargantuaSauce do these guys screw you on shipping
23:02 rue_house dunno
23:05 GargantuaSauce i guess since it's in the us i'd pay out the ass on duty anyway
23:16 rue_house !seen rikus
23:16 rue_house !seen rikus
23:16 rue_house !time
23:16 rue_house wtf
23:18 rue_house !time
23:18 tobbor My watch says its 09:06PM Mon Mar 11 2013
23:18 rue_house !seen rikus
23:18 tobbor Rikus was last seen in #avr on Dec 01 08:39 2012
23:18 rue_house !seen rikusw
23:18 tobbor RikusW was last seen in #avr on Mar 11 15:25 2013
23:18 rue_house !time
23:18 tobbor My watch says its 09:07PM Mon Mar 11 2013
23:39 Jak_o_Shadows !website
23:40 Jak_o_Shadows !help
23:40 rue_house hah
23:40 Jak_o_Shadows YOU KILLED TOBBOR
23:40 rue_house !time
23:40 rue_house wtf
23:40 rue_house w t f
23:41 Jak_o_Shadows He's dead rue
23:42 rue_house WHY
23:43 rue_house odd
23:43 rue_house no message in his logs
23:45 rue_house !time
23:45 tobbor My watch says its 09:34PM Mon Mar 11 2013
23:46 rue_house ok lets try this manually