#robotics Logs

Aug 24 2014

00:00 StructuredArray well you need 14 bits to represent 12000
00:00 GargantuaSauce 14 bits is 16384
00:00 rue_house so its 13ish
00:00 StructuredArray 13 is 8192
00:00 rue_house why did I click into 12
00:00 rue_house huh
00:02 rue_house I cant work out how to get more than 10 channels without having too many interrupts going
00:02 StructuredArray is that why you are limited to 8 servos?
00:04 mrdata hmm
00:06 rue_house I did 8 becuase I was just shifting a 1 to turn on the right bit
00:06 rue_house +- the m328 does not have a whole 8 bit port, so now a bit of code splits it up among two
00:07 rue_house I'm not cycle heavy on it yet tho
00:07 rue_house so the 328 code could, in theroy do 10 channels
00:07 StructuredArray what if you software multiplexed?
00:08 rue_house I have one timer to say that a servo needs to be started
00:08 rue_house it starts a 16 bit timer that does the pulse timing
00:08 rue_house the first 8000 counts of that are the .5ms (or whatever min. I used) the rest times off the stop of the pulse
00:09 rue_house I cant put another interrupt in there wihout the possability of an interrupt conflict that would cause a delay in one of the pulse timings
00:09 rue_house which is why most other servo controllers have so many problems, the outputs jitter by a few ns because of service delays in the code
00:10 rue_house all my serial comms are in the main loop, delays in them dont matter
00:11 rue_house you cannot fit more than 10 servo pulses in 50hz
00:13 rue_house 20ms
00:13 rue_house huh
00:13 rue_house so technically you cant fit 10 @ 2.5ms
00:13 rue_house I think my controller goes from .5 to 2.5ms
00:13 rue_house is standard 1 to 2ms?
00:14 GargantuaSauce yes
00:14 rue_house I expanded the range to get the full 180 out of the servos
00:14 rue_house most of them will do 180 without blowing up :)
00:15 GargantuaSauce yeah, most :)
00:15 rue_house oh, so I can only fit 8
00:15 rue_house zippo:/# calc .02/.0025
00:15 rue_house .02/.0025 -->> 8
00:15 StructuredArray what about a cmos multiplexer?
00:15 rue_house that would just let you do it on one pin
00:15 GargantuaSauce some will tolerate pulses at <50Hz but some will not
00:15 rue_house I thought 50hz was the standard update rate?
00:16 rue_house 50 to 60
00:16 rue_house depanding what side of the water your on :)
00:16 StructuredArray is your code assembler or c?
00:16 rue_house C
00:16 StructuredArray maybe you can tweak some of the C into assembler to get more performance out of it
00:16 rue_house but you cannot have more interrupt sources going without having service delays if multiple interrupts go off at the same time
00:17 rue_house if you dont mind 8ns timing jitter, you can do lots of servos
00:17 rue_house but 8ns will cause jitter in the servos
00:17 fluffywolf bbl, wolfy bedtime
00:17 rue_house gnight fluffywolf
00:17 rue_house dont work it too hard, it'll break
00:18 rue_house :D
00:18 StructuredArray rue_house if you hardware multiplexed your 8 servos, you could do 16
00:18 rue_house no, its not possable to have the two timers cause software interrupts without collisions
00:18 StructuredArray oh ok
00:19 rue_house UNLESS you mean using the hardware pulses and split it apart with external chips
00:19 StructuredArray yea that is what I mean, external cmos
00:19 rue_house in which case, you should be able to pull... I think ... 32 from a 328p
00:19 rue_house the 16 bit timers would have to stop themselfs, be in pin reset mode only
00:20 rue_house I like the no external chip thing cause you can get ...
00:20 StructuredArray oh hmm
00:20 StructuredArray I like external chips hehe
00:22 rue_house http://www.ebay.ca/itm/131141189364
00:22 rue_house ^^ note this varriant has a proper 6 pin isp
00:22 rue_house }:)
00:22 rue_house $2.60 ea
00:23 rue_house pretty good considering: http://www.digikey.ca/product-detail/en/ATMEGA328P-AU/ATMEGA328P-AU-ND/1832260
00:24 rue_house *at these prices, you cant save money using external chips
00:25 rue_house ? do I have a point? somewhere?
00:26 rue_house makes me want to buy antoher batch
00:26 StructuredArray ah, you are dealing with economics
00:28 rue_house I can only argue numbers to a certian point
00:29 rue_house the fact that the board with the controller, osc, regulator and reset button is cheaper than I can get a chip for....
00:29 rue_house and they are small, I can just jab them into anything
00:30 rue_house not applicable for all my projects as they dont use my standard connectors, but...
00:32 rue_house the tea is working, my eyes are not snapping shut
00:36 rue_house http://www.intermodalics.eu/sites/www.intermodalics.eu/files/images/ur10-white-bg.intext400.jpg
00:36 rue_house I got a bunch of pvc pipe fittings, but they dont quite work out
00:36 rue_house one thing I didn't notice was the difference in sizes as it goes along
00:37 rue_house I'm guessing they use concentric shafts and its belt driven
00:37 rue_house or they put the mtoors in the segments and use one hell of a reduction in the
00:37 rue_house m
00:39 rue_house when did the only person I was talking to leave? damnit!
00:39 rue_house I suppose if they use a planetary reduction and crown gears
00:40 rue_house hell of a lot of stress on things tho
01:37 mugenzebra Hi all, I have a question about power consumption. I have a sonar IC MB1010, it says it's "2 mA typical current draw", I wonder how long can a 2500mAh battery sustain this IC?
01:38 rue_house hmm well
01:38 rue_house if we use 1.3 as a magic number
01:38 rue_house then current * Ah * 1.3 = runtime
01:39 rue_house or was it current * runtime * 1.3
01:39 rue_house yea,
01:39 rue_house current * runtime * 1.3 = Ah
01:39 rue_house you want runtime
01:39 rue_house Ah/(current * 1.3)
01:39 rue_house 2500/(2*1.3)
01:40 rue_house my guess is 961 hours
01:40 rue_house which will be wrong, because the batteries internal leakage is significant at that low a current
01:40 rue_house lets ballpark 400 hours
01:41 GargantuaSauce i would strongly suspect that figure is IDLE current also
01:41 GargantuaSauce and when you're actually pinging, it'll be much higher
01:41 rue_house I answered your question, now tell me everything about how your spinal cord works
01:42 mugenzebra still trying to understand your calculation haha
01:42 GargantuaSauce unit analysis
01:42 rue_house 1.3 is a magic number used in fire alarm systems
01:42 rue_house for sealed lead acid, but whatever
01:42 GargantuaSauce 2500 mA * h / 2mA * that weird fudge factor
01:43 mugenzebra I see thank you
01:44 rue_house the runtime of a battery changes quite a bit with the amount of current you pull out of it because of its internal resistance
01:45 rue_house where is my spinal cord answer...
01:46 mugenzebra should i take you literally? lol
01:46 e_house prepares to remove his answer from mugenzebras b
01:47 rue_house I cant find any maps of surface nerve routing, ARG
01:47 GargantuaSauce because it's different for every person
01:48 rue_house +-
01:48 rue_house its approximitly standard
01:48 rue_house there are a number of thrupoints from the inner to outter hull
01:56 rue_house http://www.primary-surgery.org/ps/vol2/html/sect0058.html
01:56 rue_house thats worth a bookmark
02:08 rue_shop2 vacuum former, next step is to install the element in the heater box -- not tonight
02:08 rue_shop2 cnc machine, next step is to assemble the control for the Y axis, make sure the dc servoloop works -- possability
02:08 rue_shop2 3d printer, next step is to point-to-point the motor driver board -- also a posability
02:08 rue_shop2 bench power supply, needs the dc-dc designed -- I think I'd need more mental power than I can pull off now
02:10 rue_shop2 rue?
02:10 rue_shop2 yes?
02:10 rue_shop2 your up!
02:10 rue_shop2 yea
02:10 rue_shop2 ok, work with me for a bit?
02:10 rue_shop2 np
02:10 rue_shop2 bench power supply
02:10 rue_shop2 ok
02:11 rue_shop2 plan A was to use an analog error system and control pwm width with it, but plan b is a timer thats reset by the target votage
02:11 rue_shop2 plan B may be harder to filter
02:11 rue_shop2 ok, any other thoughts?
02:11 rue_shop2 no
02:12 rue_shop2 shall we try building a flipflop based reset pwm regulator?
02:12 rue_shop2 sure, go for it, I'm kinda asleep
02:13 rue_shop2 so, we need a flipflop, thats set at a rate of 500Khz, and is controlled by an overriding reset
02:13 rue_shop2 does the 7474 have a reset that overrides the D+clk?
02:13 rue_shop2 lets take a look
02:14 rue_shop2 yea, a low on set or reset overrides the clock/data
02:15 rue_shop2 so, D goes high, clk goes to a 500Khz osc and reset goes to the voltage comparitor
02:15 rue_shop2 sounds good, shall we build?
02:16 rue_shop2 k, what do you want to use as an osc?
02:16 rue_shop2 dare I say 555?
02:16 rue_shop2 why cant we do all that with a 555
02:16 rue_shop2 its got no edge controlled data line
02:16 rue_shop2 right...
02:17 rue_shop2 so, we need a 555, 7474 and.. whats the comparitor
02:17 rue_shop2 lm393
02:19 rue_shop2 and a breadboard
02:19 rue_shop2 you really need to etch the control circuit for the solar lights so i can get that one back
02:19 rue_shop2 yea, maybe thats a good one for tommorow
02:19 rue_shop2 see if you remember ;)
02:20 rue_shop2 ya know
02:20 rue_shop2 ?
02:20 RifRaf rue_shop2, making a vacuum former?
02:21 rue_shop2 if we use a cmos flipflop, we can run this all on 12V, meaning we can drive the fet direct
02:21 rue_shop2 RifRaf, yea
02:21 rue_shop2 been gathering parts for a while
02:21 RifRaf cool, place i now work has a 4m x 4m one
02:21 rue_shop2 wow
02:21 rue_shop2 what do you form with that?
02:21 rue_shop2 hottubs?
02:21 RifRaf yep, lookin forward to checking it out
02:22 rue_shop2 making mine 46cm square
02:22 rue_shop2 1400W
02:22 rue_shop2 how the hell do you heat 4m square!?
02:28 rue_shop2 rue
02:28 rue_shop2 rue
02:29 rue_shop2 rue!
02:29 rue_shop2 yea?
02:29 rue_shop2 I cleared a breadboard for you
02:29 rue_shop2 thanks
02:29 rue_shop2 so, put chips in it?
02:29 rue_shop2 right, right, ok, I got it
02:30 RifRaf have no idea right now, but will soon find out
03:15 RifRaf rue_shop2, http://imgur.com/yeryuIv http://imgur.com/tIIzjHG
03:18 RifRaf the whole setup http://imgur.com/1CpIkI8
03:32 SquirrelCZECH RifRaf: hi! :)
03:32 rue_shop2 huh, simple, works...
04:02 RustyShackleford so I found a safe hidden in the wall at this new house
04:03 RustyShackleford I'm thinking I can build some sort of machine that will try every combination
04:03 RustyShackleford and output the combo on an LCD screen
04:13 rue_house aliexpress is giving me a bad habbit
04:13 rue_house anything I need even 1 of I buy in lots of 100
04:13 GargantuaSauce so build 100!
04:14 rue_bed the bench supply is only 2 channel
04:14 rue_bed I fear to think a 100 channel bench supply
04:15 rue_bed I mean, 3 channels, maybe, 100? no
04:15 theBear 3 is pretty close to 100
04:15 rue_bed .... yea
04:15 GargantuaSauce think of it as a 50 channel motor driver
04:15 rue_bed maybe I should have ordered 2 lots?
04:15 theBear i wanna be a 50 channel train driver, with a little cap
04:45 mumptai GargantuaSauce, I find FSMs a cumbersome to deal with after a they have grown too much
04:46 mumptai also abstractions are tricky, even with the extension to hierachical and concurrent FSMs
04:46 mumptai and basically its the typical: "there must be a better way"
04:50 mumptai GargantuaSauce, btw, what is you favorite coding style for FSMs? A big switch()-statement for all states, enum to encode states and this thing run repeatedly (i.e. non-blocking implementation / cooperative "multitasking")
04:50 mumptai ?
04:53 GargantuaSauce each state consisting of a struct with an array of function pointers is nice
04:53 GargantuaSauce or in c++ perhaps a map of functors
04:55 mumptai what part sets the next state?
04:56 GargantuaSauce those functions define the change in state and the synchronous operations to carry out in the transition
04:58 mumptai and you want function-poointers because you like to reuse functions in multiple states? or change them at runtime?
04:59 GargantuaSauce well and to provide a generic and reusable framework for the definition of a state and its transitions
05:00 GargantuaSauce making them mutable sounds like an awesome way to make your thing super hard to debug
05:01 GargantuaSauce i am running out of big words, time for bed
05:02 mumptai ahh, timezones
05:02 mumptai good night
05:02 mumptai thanks for your insight
05:04 GargantuaSauce it's a lot more fun to do in a scriptey language where objects are just maps/tables and functions are first class objects
05:38 SquirrelCZECH hmm
05:38 uirrelCZECH is writting software for his baloon pro
05:38 SquirrelCZECH or airship
05:38 SquirrelCZECH ehm, so far too easy
05:38 SquirrelCZECH something is terribly wrong
06:04 RifRaf SquirrelCZECH, hi there sorry been out but time to crash now, start new job in a few hours :)
06:04 SquirrelCZECH :D
06:05 SquirrelCZECH RifRaf: still working on triplestruder?
06:05 RifRaf SquirrelCZECH, yes but no, had to pack everything away for a bit, but is first thing to finish when i get settled
06:05 SquirrelCZECH I see :)
08:15 Tom_itx rue_bed, the place i worked at moved the sheet into an oven until it was hot enough then brought it over the form and sucked it down
08:15 Tom_itx it was probably 8' x 25' or so
08:16 Tom_itx they also had a bunch of smaller ones
11:25 rue_house Tom_itx, how much time to move it?
11:25 rue_house I imagine they go too cold pretty quick
11:41 Tom_itx it went straight from the oven to the form
11:41 Tom_itx on a conveyor
11:41 Tom_itx it would droop in the middle as it was being moved
11:41 Tom_itx 2k deg oven i was told
11:41 Tom_itx i doubt it was that hot
11:43 Tom_itx http://www.dickssportinggoods.com/largeImage/index.jsp?ab=Product_PageElement_MainProductImage&LargeImageURL=/graphics/product_images/pDSP1-9945256dt.jpg
11:45 Tom_itx that was the oven i pulled a guy from once
11:45 Tom_itx his hand got caught in the sheet clamps and it was headed for the oven
11:55 deshipu I only just realized that analog in pins on arduino work as digital io too
12:00 Tom_itx of course they do
12:01 deshipu so now I can add a buzzer and some leds ;)
12:02 deshipu for an audio-visual multimedia orgy
12:04 rue_house so it looksl ike the spinal cord contains a signifcant amount of the processing for motor and sensory functions
12:04 Tom_itx make sure the 'buzzer' is �C compatible
12:04 deshipu Tom_itx: what do you mean?
12:04 deshipu Tom_itx: it's the usual quartz thing
12:08 rue_house I just worked out how to combine the current and voltage limiting functions for the switching bench supply
12:08 Tom_itx use your body as a resistor?
12:09 rue_house the reset on transistor control flipflop can be anything, and I can just dititally OR the voltage and current limit comparitors
12:10 rue_house I need to work out how to split the view of a camera for 'VR' stereo vision
12:11 Tom_itx prism
12:11 rue_house I might have some from some ... binoculars
12:11 m_itx looks at rue_house all cross
12:11 rue_house I had a binocular that turned into a monocular
12:12 rue_house screw it
12:12 e_house gets some icecream for break
12:13 Tom_itx should i keep all these floppies i've been saving?
12:15 Tom_itx apparently you can still buy them
12:17 rue_house just 3 of the 8"
12:17 rue_house 3 of the 5.25"
12:17 rue_house and keep 10 of the 3.5"
12:17 Tom_itx problem i have is getting them to work between 2 drives
12:17 rue_house yea
12:17 rue_house always was
12:18 Tom_itx that's why i hate to toss any
12:18 Tom_itx never know when they'll work
12:18 rue_house works better if you only format them to 720k
12:18 Tom_itx the file is bigger than that
12:18 rue_house what I'd do in my dos days was to format with full secotrs checking, anything with any bad sectors I'd toss
12:20 Tom_itx if i could get dos to read a usb stick i'd be set
12:20 rue_house yea
12:20 rue_house for a bit of a cost you can get flash card floppy simulators
12:20 rue_house but...
12:21 Tom_itx windows didn't like the last SD i got
12:21 Tom_itx it was too big
12:21 Tom_itx so i put it in the phone
12:21 rue_house honestly... I bet you could get an avr to clock data out fast enought o simulate a floppy
12:21 Tom_itx i'm not gonna mess with it
12:21 Tom_itx i think pepsi did that
12:22 rue_house you CAN makea sudo-floppy on a cd
12:22 rue_house and I think dos can boot it
12:22 rue_house er on it
12:22 rue_house which can allow you to install dos
12:22 rue_house 2.88M
12:22 Tom_itx that won't help transferring files
12:23 Tom_itx i'm not gonna waste a cd each time...
12:23 rue_house use dos serial transfer program
12:23 rue_house hmm, what was it called...
12:23 Tom_itx laplink
12:23 rue_house no
12:23 rue_house the one that came with dos
12:23 Tom_itx no clue
12:23 rue_house :) its been too long
12:24 Tom_itx i wouldn't need level shifters would i?
12:24 Tom_itx just plug it in
12:24 Tom_itx with 2-3 crossed
12:24 rue_house no you just use a serial cable between the two computers
12:25 Tom_itx i'm not even sure i still have one
12:25 rue_house if the bios will pre-enumerate usb devcies...
12:25 rue_house some do
12:25 Tom_itx it's way too old
12:26 rue_house hmm, I dont have an iso of a full dos installed drive I can find the name of that program
12:27 rue_house I think its called interlink
12:27 Tom_itx i got 6.22 here
12:27 Tom_itx what goes on the winders side?
12:27 Tom_itx that or some serial terminal
12:27 Tom_itx procomm?
12:28 Tom_itx yeah there's interlnk.exe
12:28 Tom_itx and intersvr.exe
12:28 Tom_itx wtf is that?
12:29 Tom_itx server side of interlink
12:32 rue_house same program
12:32 rue_house interlnk.exe thats it
12:33 rue_house yup
12:33 Tom_itx now to find a cable
12:33 rue_house slow as all hell, so makea big zip and leave it overnight
12:33 Tom_itx is the 9pin 2 2 on the 25 pin?
12:33 Tom_itx or are they swapped
12:33 rue_house yea
12:33 Tom_itx yeah what?
12:33 rue_house 9<->25 is 2-2 and 3-3
12:33 rue_house dont ask whats ground, I forgot
12:34 Tom_itx so i flip one either way
12:34 Tom_itx i have 3 cables labelled 'cereal' here
12:34 rue_house heh
12:34 Tom_itx i'll see what plugs are on the back now
12:34 Tom_itx i'm sure i need a gender bender
12:35 Tom_itx rue_house
12:35 Tom_itx don't forget that program name
12:36 Tom_itx i'm sure i'll be asking you for it again
12:36 rue_house hmm I wonder,
12:36 rue_house the cat that went missing has a whole bunch of wiskers broken off on one side
12:36 rue_house I wonder if she got them caught in something and couldn't come home for lieka week
12:37 rue_house !bookmark toms serial transfer program dos name
12:37 rue_house ok I'm gonna wake up
12:38 rue_house zlog,
12:38 Tom_itx ok one has 9 pin and the other has both
12:42 Tom_itx what should i use on the windows side?
12:43 rue_shop2 go with 9
12:43 Tom_itx no
12:43 rue_shop2 2<->3
12:43 Tom_itx program
12:43 rue_shop2 3<->2
12:43 Tom_itx i know that
12:44 rue_shop2 use srv on the dos, use lnk on the windows side
12:44 Tom_itx i suppose i should check them
12:44 rue_shop2 5<->5
12:44 rue_shop2 iirc
12:44 Tom_itx i bet windows doesn't have it yet
12:44 rue_shop2 copy it from dos
12:44 rue_shop2 use -v when you copy it
12:44 rue_shop2 or maybe I can find you a copy]
12:44 Tom_itx i have it
12:45 rue_shop2 symantic did a good job of the dos 6.22 utility set
12:46 rue_shop2 I think thats who wrote everything...
12:46 Tom_itx now i run intersvr and it's bitching about drive D
12:46 rue_shop2 ?
12:46 rue_shop2 whats D
12:46 Tom_itx backup
12:47 Tom_itx i probably need to wiggle the cables again
12:47 rue_shop2 hmm
12:47 Tom_itx i'll work on it tonight
12:47 Tom_itx i bet procomm would work too
12:48 rue_shop2 helps heaps having happy host hardware
12:49 Tom_itx i forgot how to use it now
12:57 rue_shop2 iirc, you set up the server, and when you connect with the client you can choose and download files
13:01 Tom_itx i need to figure out what port i'm on
13:01 Tom_itx i'm trying procomm and realterm on the windows side
13:02 Tom_itx procomm - ascii upload
13:03 rue_house I will never mourne the loss of baud rates, parity, and stop bits with the oncome of virtual usb comm ports
13:04 fluffywolf virtual com ports have all those exact same settings, you know.
13:04 rue_house but they dont do anything
13:04 fluffywolf well, depending on the type. some pretend to be a rs232 port more than others.
13:04 rue_house I mean, yea they do if it goes to an adapter, but not if its just a usb endpoint to a device
13:05 fluffywolf hrmm. sdp-si sells metric timing pullies, but not metric timing belts?
13:05 Tom_itx i've no idea what plug is what port here
13:06 Tom_itx i'll work on it later...
13:07 rue_shop2 have a .1" jumper?
13:07 rue_shop2 push it between pins 2-3
13:08 rue_shop2 open the comm port in any program and type
13:08 Tom_itx ok
13:08 Tom_itx i'll try it later
13:08 rue_shop2 make sure hardware crap is off
13:08 Tom_itx i got stuff to do right now
13:08 Tom_itx no flow control
13:09 Tom_itx then i'll double check this cable
13:09 rue_shop2 yea
13:09 rue_shop2 hahah
13:09 Tom_itx :)
13:10 rue_shop2 I need to update the volume control on the jukebox to use ajax methods to send the volume urls without reloading the frame..
13:10 rue_shop2 the jukebox is a p100 that was put togethor in 2000
13:10 rue_shop2 its got the same hardware as it did then
13:10 rue_shop2 prettymuch same software
13:11 rue_shop2 it was old then, I'm kinda amazed its still going
13:11 rue_shop2 http://www.learnabout-electronics.org/Oscillators/osc44.php
13:11 Tom_itx go figure... the gender bender just fell apart
13:11 deshipu hmm, I wonder, would it make sense to connect the unregulated lipo to one of the arduino's analog ins, so that I can tell when the battery runs out?
13:11 rue_shop2 ^^ think I can believe the numbers from that?
13:11 rue_shop2 Tom_itx, heh, too ol
13:11 rue_shop2 d
13:12 Tom_itx the rivets fell thru the hole
13:12 rue_shop2 :/
13:12 Tom_itx i'll fix it or find another one
13:12 rue_shop2 :( I cant remmeber the pinout of a 7474 off the top of my head anymore
13:13 m_itx refrains from any head comm
13:13 fluffywolf I still have my old ttl data book in storage somewhere for when I'm working on projects that require remembering 74xx parts.
13:13 rue_shop2 I have a large reseve of pdf data sheets
13:14 rue_shop2 I made a internal webpage for searching them
13:14 rue_shop2 searching for them
13:15 fluffywolf Tom_itx: only adapters I have handy aren't for serial... serial ones are off in storage somewhere.
13:19 fluffywolf (I could probably stick the non-serial ones in storage too, being single and all....)
14:31 rue_shop2 re-arranged the cabinet sets so that all the components used when building things are by the build space
14:32 rue_shop2 but it looks like to really fix it properly I have to do a drawr-contents transfer between a few cabinets
14:32 rue_shop2 thats a lot of work
15:12 Tom_itx how the hell do you get firefox to stfu about updates?
15:13 GargantuaSauce use a browser that doesn't suck
15:13 Tom_itx such as?
15:13 GargantuaSauce no such thing! that's the joke
15:13 Tom_itx xactly
15:13 fluffywolf I've yet to find a browser that doesn't suck. however, my firefox doesn't mention updates ever...
15:14 fluffywolf dillo is nice....
15:14 Tom_itx found it... never check for updates
15:14 Tom_itx bastards
15:22 rue_shop2 take 2 resistors, 1 capacitor, and a 555, attempt to make a 250Khz oscillator, any duty := Remember why you keep thinking its a good idea to throw out the 555's and use tiny13's.
15:23 fluffywolf my amplifiers oscillate and my oscillators don't.
15:27 e_house swaps the labels on fluffywolfs schema
15:27 rue_house honestly, I think I can make a tiny13 output 250khz with no code, isn't there a fuse for outputting the clock on a pin?
15:28 rue_house why are there no 4 pin osc chips, VCC, RC, OUT, VDD ????
15:30 fluffywolf lm3909... and they're a charge pump too! :P
15:30 xorly rue_house build one, sell, ???, profit!
15:31 rue_house *sigh* the control timer on the washing machine is going, ... I'd better start piling arduino and relay parts
15:31 fluffywolf or get a new timer.
15:31 rue_house oh yea, 3909, I forgot, man that was a neato chip
15:31 rue_house I wonder if I should make a 4 pin rc osc sip
15:31 fluffywolf I still have a couple... they've been discontinued for quite some time.
15:32 rue_house yea, I looked on aliexpress for them, didn't see any at an ok price
15:32 fluffywolf you can get 3-pin crystal oscillators...
15:32 rue_house flash an led on a AA for what, 3 years?
15:33 fluffywolf depends on flash right, brightness, and whether your AA says duracell or china...
15:33 rue_house but low freq, low freq!
15:33 fluffywolf rate
15:33 rue_house hmm
15:33 fluffywolf make a little daughterboard with a tiny uC, a programming plug on top, and three pins on the bottom.
15:33 rue_house how could I make the smallest smt RC osc
15:34 rue_house relaxation osc?
15:34 rue_house must be able to do it with like 2 transistors
15:34 fluffywolf a 555? :P
15:34 rue_house fff no
15:34 rue_house something you just put a cap to ground and a resistor to + on the RC and it oscillatres
15:35 fluffywolf a schmitt trigger inverter and a transistor?
15:35 rue_house http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/ietron/unijun4.gif
15:35 rue_house no I mean REALLY basic
15:36 fluffywolf the more basic you make it, the more prone it is to finding an analog point that makes it happy.
15:36 rue_house but I dont think ujt's are available in smt
15:36 rue_house can I use a TL341...
15:36 rue_house 431
15:37 rue_house oh wait, is there a 1 gate 7414?
15:37 fluffywolf dunno
15:38 rue_house no that wouldn't work
15:39 fluffywolf my rc oscillators with less than three transistors usually ended up finding an anlog voltage.
15:39 rue_house you need to increase the loop gain or change the phase offset
15:40 fluffywolf or build an amplifier instead. :P
16:05 rue_house I think I have it down to 3 smt transistors
16:06 rue_shop2 but its because I cant find a good smt SCR
16:32 Tom_itx rue_shop2, for what?
17:03 rue_shop2 for a little oscillator module
17:04 rue_shop2 odd, not sure how I got to taking a camera apart
17:04 e_shop2 goes back to the power su
17:19 rue_shop2 wow, I think I like digital power supplies
18:28 Loshki I went to alibaba and typed in robot vacuum. 278,566 Products, of which about 1000 appear to be obvious Roomba knockoffs. Do these all really exist? Are they about to become commodity items? Or will most of them die like Japanese soft drinks?
18:45 ace4016 Loshki, depends on which ones are marketted
18:45 ace4016 robot vacuums will probably become more common place
18:46 ace4016 there are already alternatives to roomba on the market iirc
18:46 ace4016 not just chinese knock offs
18:54 Loshki ace4016: well, here in the US it's irobot (the market leader) or neato. There are some oddball brands on Amazon but they're always Chinese and always have zero reviews. And both brands are notorious for quality/reliability issues.
18:57 Loshki Maybe I'll ask in ##economics...
19:29 rue_shop2 power supply circuit is good except for the .2V ripple
19:31 Tom_itx more caps?
19:33 rue_house its the detector thats the problem
19:33 rue_house the comparitor must have .2V schmitt on it
19:34 rue_house using a tl431 isn't easy, its min voltage is 2.5V, meaning I'd have to offset it 3V under
19:36 fluffywolf speaking of caps, anyone have some BIG (soda can or larger... sprague compulytic or similar) caps in the 80V range?
19:37 fluffywolf the type you use to filter three 9A stepper motors with switching drivers running off a 56V supply. :)
19:37 rue_house hehe
19:38 rue_house whats the ripple current?
19:38 fluffywolf dunno
19:38 rue_house you want 1000uF/amp
19:38 fluffywolf I do know that when decelerating, the motors are going to dump a whole lot of power back into the supply, and I don't want more than a 10V rise...
19:39 rue_house heh, yea, I had the power supplies on my cnc shut down cause of that
19:39 fluffywolf and I don't want that. :P
19:40 fluffywolf I don't know if my supplies will shutdown, crowbar, or ignore it... and I don't want to find out!
19:43 fluffywolf I also don't know what they'll do on startup with a ~short of a capacitor, though. heh.
19:44 fluffywolf the manual says I need bypass schottkys when putting them in series, however.
19:44 fluffywolf (two 28V supplies)
19:44 Tom_itx mine's only 48v 18A
19:44 Tom_itx but i used a bunch of small caps instead
19:45 rue_house I think I have 4 24V 20A
19:45 fluffywolf I have three spare 28V 20A supplies, going to use two of them.
19:45 fluffywolf they're labelled 24V, but that means 27.7, since they're meant for floating batteries.
19:46 fluffywolf or maybe they're 15A. don't remember right now.
19:46 fluffywolf or 25...
19:46 uffywolf should go check instead of gues
19:47 fluffywolf 27V 25A
19:51 fluffywolf I figure 25A @ 54V should be more than enough. :)
19:56 rue_shop2 if I'm stuck with a regulator that can only go down to 2.5V, I might as well use one thats easy to use
19:56 rue_shop2 damn, this means I need something like a -5V rail to bias off the controller on
19:56 fluffywolf the motors are rated for 9A/phase, but at 1.3V... the only time they'll pull close to 9A off the supply is doing full-power stepping, and even all three at once would be within the limits of the supplies...
19:57 rue_shop2 which makes a mess of power rails everywhere
19:57 rue_shop2 4 wire?
19:57 fluffywolf yes
19:57 rue_shop2 so 18A continious per motor
19:58 rue_shop2 sounds like you would be better off with higher current, lower voltage supplies
20:00 fluffywolf the motor voltage is lower than the supply voltage... the drivers do switching to regulate the winding current.
20:01 fluffywolf you need the high voltage to get that current flowing faster, then it starts chopping, and the supply current drops.
20:01 fluffywolf the rules I've heard was to size the supply assuming the motors draws half or 2/3rds of its rated amps, and you'll end up with plenty of spare power.
20:01 rue_shop2 maybe I should hang this whole thing off the + rail and make it think its a - votlage supply
20:02 rue_shop2 its all isolated anyhow
20:03 fluffywolf "The easiest factor in choosing a power supply is its current rating, which is based on your motor ratings. A motor control will always draw less than 2/3 of the motor’s rated current when it is parallel (or half-winding) connected"
20:03 fluffywolf I have 9A motors, so by that rule, I need an 18A supply... I have 25A.
20:03 fluffywolf (9 * 2/3 = 6, * 3 motors = 18)
20:04 rue_shop2 half winding
20:04 rue_shop2 thats when using 6 wire motors as 4 wire
20:04 fluffywolf these are 4-wire motors... they draw what they say, and there's no wiring you can change.
20:04 fluffywolf also, the rest of the line is " and 1/3 of the motor’s rated current when it is series (or full-winding) connected. That is to say, a 6 amp per phase motor will require a 4 amp power supply when wired in parallel and a 2 amp power supply when wired in series."
20:05 fluffywolf I've heard these guidelines before, and I think they're actually rather conservative.
20:10 fluffywolf hrmm, there's other guidelines that say I might be better off with a lower voltage supply due to how low the inductance of these motors is
20:11 fluffywolf that is, with such a low inductance motor, I don't need a high voltage to get current flowing.
20:11 fluffywolf I really want fast rapids though....
20:13 fluffywolf I haven't been able to find exact specs for my motor though, which annoys me.
20:17 fluffywolf the part number doesn't quite fit the format given for others in the manufacturer's catalog
20:17 fluffywolf especially since their current catalog seems to say they only make 8-wire motors. heh.
20:20 fluffywolf it gives a part number breakdown table thingy, but only gives one letter, for 8-wire... mine has 4 wires and a different letter there. heh.
20:21 fluffywolf for the closest similar motor in the catalog, they give specs at an 80V supply.
20:24 fluffywolf bah! the german language catalog lists the letter I have as 4 wires. lost in translation? heh
20:25 fluffywolf F is 4, S is 6, E is 8. is that how you count in german? heh
20:26 fluffywolf or did the german company use the first letters of the english numbers?
20:26 fluffywolf lol
20:30 rue_shop2 ince, svi, dry fear, funf, sex, seben, oct, nien, sien...
20:31 fluffywolf still can't find my exact motor, but now I have an idea of how it breaks down... looks like a SECM299-F9.0AE-1 is a 4-wire version of a SECM299-E6.4-AE, I think... and if it has the same ratings, 1.1mh inductance.
20:31 fluffywolf according to the guideline on the same page as the current one, with such a low inductance, I should only use a 34V supply max.
20:33 fluffywolf I could just skip my shiny regulated supplies, and find a 24V transformer, a bridge rect, and some really big caps...
20:33 rue_shop2 I cant ref the whole thing off the + output because I have one controller that does both channels
20:34 uffywolf is tempted to do that, and save the shiny supplies for projects that
23:13 cell_ hello
23:16 fluffywolf heyas
23:16 cell_ i was wondering how to get/build a cheap humenoid robot?
23:17 fluffywolf good luck with that.
23:17 cell_ why are they so expensive?
23:20 fluffywolf hundreds of joints, complex controls for balance, compact yet powerful power source,...
23:22 cell_ its usualy 16 servo designs
23:23 cell_ u need gyro for every limb?
23:23 fluffywolf we have different definitions of humanoid, then.
23:23 fluffywolf no
23:24 cell_ oh yea sorry im talking about the small scale ones
23:25 cell_ but there still over the 1000$
23:30 RustyShackleford so I found a safe hidden in the wall at this new house
23:30 RustyShackleford I'm thinking I can build some sort of machine that will try every combination
23:30 fluffywolf I already told you what that machine was called and how to build it. :P
23:31 cell_ lol
23:31 RustyShackleford well, stepper motor + ?
23:31 RustyShackleford arduino maybe?
23:31 fluffywolf or just drive it off your computer
23:32 fluffywolf get a cnc breakout box, a stepper driver, and a motor.
23:32 cell_ and some dicktape
23:32 cell_ ducktape*
23:32 RustyShackleford fluffywolf, how much do you think those parts would run?
23:33 fluffywolf you can probably pick up a motor and driver for $30, and build the breakout box... running the stepper driver straight off a parallel port is quite traditional.
23:34 cell_ how are you going to check if its open or not?
23:34 fluffywolf you'll also need some kind of torque sensor. the easiest is probably to mount the stepper motor on a microswitch, such that when the motor housing twists, the switch is triggered.
23:34 fluffywolf cell_: if his safe is like most, when it's open, the knob will stop turning.
23:35 fluffywolf your safe just had a knob, no lever, right?
23:35 cell_ oh ok
23:35 RustyShackleford yep thats how this one is supposed to work
23:35 fluffywolf s/had/has
23:35 RustyShackleford fluffywolf, yep
23:35 fluffywolf then yeah, when it's open, it'll pull the bolts back and stop... then your motor will twist, and trip your "it's open!" switch.
23:36 cell_ thats going to burn the motor
23:36 RustyShackleford can most stepper motors rotate in either direction?
23:36 fluffywolf no, it won't, for two reasons. the first being steppers don't mind being stalled, the second being it'll stop trying once it thinks it's open.
23:37 fluffywolf all steppers can rotate in either direction
23:38 RustyShackleford a problem that still has to be solved in syncronizing the stepper motor with the safe dial
23:38 fluffywolf my first thought would be rubber hose and a hose clamp.
23:38 RustyShackleford even if I syncronize it manually, isn't it possible that it would lose track of where 0 is?
23:39 cell_ thats why u need the switch right?
23:39 cell_ to home it
23:39 fluffywolf if it loses track, it's because the motor stalled or your coupler slipped, both of which should be avoided by design.
23:39 RustyShackleford no, the switch he's talking about is to shut off the motor when tit stalls
23:40 RustyShackleford i.e. when the safe is open
23:40 fluffywolf cell_: no, you need the switch to sense when the torque increases enough to think the safe might be open.
23:41 fluffywolf it's quite possible for the motor to stall or the coupler to slip... if it stalls, spin slower, with more current, or get a bigger motor... if it slips, improve design somehow. periodic checks (have your software have a spin-to-0-and-stay-there option) every half hour or so might be a good idea, so you both know that it slipped, and know when it was last good, so you don't have to retry as far.
23:42 fluffywolf I'd suggest a nema 23 stepper... it might be overkill, but the cost isn't much more, and will help prevent stalling.
23:43 fluffywolf http://www.ebay.com/itm/NEMA-23-Stepper-Motor-CNC-Mill-Robot-Lathe-RepRap-Makerbot-3D-Printer-/121146152794 something like that
23:44 fluffywolf although that one is a 6-wire, can be annoying. (4 or 8 are betteR)
23:45 fluffywolf actually, looks like most of the nema23s are 6-wire. nevermind.
23:45 cell_ why the extra wires?
23:46 fluffywolf cell_: I take it you know absolutely nothing about stepper motors?
23:47 cell_ apart from a sensor or somthing i have no idea
23:48 fluffywolf right. Go RTFM. I'm not going to type out an introductory text for you.
23:48 cell_ lol
23:48 cell_ i wasnt asking
23:49 cell_ im looking for servo's anyway
23:49 fluffywolf RustyShackleford: and then get a driver like http://www.ebay.com/itm/CNC-One-Single-Axis-TB6560-3-5A-Two-Phase-Hybrid-Stepper-Motor-Driver-Controller-/321167580902
23:49 fluffywolf you can get cheaper drivers, but they might be undersized.
23:52 RustyShackleford fluffywolf, awesome thanks
23:52 RustyShackleford how did you learn about all this? Do you build CNC machines?
23:52 fluffywolf occasionally, yes.
23:53 fluffywolf how hard is it to turn the knob on your safe?
23:53 RustyShackleford well there are some sticky spots
23:53 fluffywolf if it's stiff, you might need a belt or gear reduction, but that rather complicates the design.
23:54 fluffywolf how tapered is the knob? as I said, my first guess for a coupler would be some rubber hose and a clamp...
23:55 fluffywolf just put something on your motor shaft about the same diameter as the knob, then use a 1" piece of rubber hose and two hose clamps.