#robotics Logs
Nov 29 2017
#robotics Calendar
12:00 AM Gene_home: I do not believe all those robots are customs in the video.....???? but then again, they are not the same either. Lots of time in those if they are customs
12:03 AM anonnumberanon: yeah most are custom
12:03 AM anonnumberanon: sometimes they use the KHR-3HV as a base
12:03 AM anonnumberanon: but it's like $1200
12:04 AM anonnumberanon: little more... https://robosavvy.com/store/khr-3hv.html
12:05 AM Gene_home: http://www.robotshop.com/en/biped-development-platforms.html?dir=desc&order=price
12:10 AM Gene_home: https://es.aliexpress.com/wholesale?catId=0&initiative_id=SB_20171128220908&SearchText=17dof+robot
12:20 AM anonnumberanon: the black one in that last link you posted is the one i have
12:29 AM Gene_home: are you happy with it? Doesnt look like it has an IMU
12:34 AM Gene_home: what is your total cost?
12:37 AM anonnumberanon: yeah it had nothing lol
12:37 AM anonnumberanon: just the frame i got and i bought 17 servos
12:37 AM Gene_home: gota crash, thanks for the entertainment
12:38 AM anonnumberanon: ttyl
12:38 AM Gene_home: is yours working?
12:38 AM anonnumberanon: like $300 into it so far
12:38 AM Gene_home: do you have code?
12:38 AM anonnumberanon: not yet
12:38 AM anonnumberanon: i am working on it
12:38 AM anonnumberanon: but yeah i have code but to run it with a custom servo controller, not what you find on the market
12:40 AM anonnumberanon: working on the servo controller right now
12:40 AM Gene_home: arduino?
12:40 AM anonnumberanon: yeah pretty much, it's an
12:40 AM anonnumberanon: AVR without an Arduino bootloader
12:40 AM anonnumberanon: the chip that the Arduino Uno uses
12:41 AM rue_mohr: but you can still buy arduino boards, which are nice and cheap
12:41 AM rue_mohr: just casue its an arduino dosn't mean you have to use it with arduino
12:41 AM rue_mohr: its just an avr
12:41 AM anonnumberanon: correct
12:41 AM Gene_home: cool! will have to ponder, enjoy!
12:41 AM anonnumberanon: see ya
12:42 AM * anonnumberanon may have to finish his controller sooner than expected
12:43 AM anonnumberanon: there is always deshipu's complete solution too
01:02 AM rue_mohr: huh, the usb powered amp I made sucks
01:02 AM rue_mohr: it looks like a) the usb bus is NOISY AS ALL HELL
01:02 AM rue_mohr: b) it sounds like the amp I used dosn't like running on 5V
01:03 AM rue_mohr: ... why is my usb bus so noisy??
01:03 AM Jak_o_Shadows: Remind me in a couple of hours and I'll look at mine
01:06 AM rue_mohr: hmm its the usb power off my ill monitor, maybe I should change caps in it
01:07 AM rue_mohr: but its clipping like all hell
01:07 AM rue_mohr: I thought 2.5V would be enough headroom for a standard level amp
01:07 AM rue_mohr: normal audio impendence is 1k right?
01:07 AM rue_mohr: theBear, 1k or 600R?
01:08 AM rue_mohr: oh 600R
01:08 AM rue_mohr: heh
01:08 AM rue_mohr: oh 2V p-p
01:08 AM rue_mohr: I need a different amp for this
01:10 AM rue_mohr: eeek yea, the lm358 is only good to within 2V of the power rail
01:11 AM rue_mohr: :/ change it out for a mcp6002
01:12 AM rue_mohr: bugger, so much for making good use of a lm358
01:12 AM rue_mohr: and I suppose I should shunt the input with another 1k
01:13 AM AchiestDragon: buffer the ouputs with transitors / power mosfets iirc the 358 is a diferential pair out should be able to drive a pair of mosfets push pull by making the ouput like a darlington pair , should give you a bit more boost
01:14 AM rue_mohr: its not a power amp
01:14 AM rue_mohr: its a line amp
01:14 AM rue_mohr: for some reason most of the devices I have cant put out enough signal for the speakers I have
01:14 AM rue_mohr: I'm not just talking about one case
01:14 AM rue_mohr: I'm talking about lots of devices and lots of speakers
01:15 AM rue_mohr: I had enough when the speakers in a monitor I have are barely audiable with a little room noise when all the volume controls on the computer are maxed out
01:15 AM rue_mohr: the android tablet is the same gig with the speakers on my desktop here
01:15 AM AchiestDragon: https://s-media-cache-ak0.pinimg.com/originals/54/8f/f3/548ff3d829eaeeb606ce09dad41c29f7.jpg
01:15 AM rue_mohr: the computer is fine, not the tablet
01:16 AM rue_mohr: nono
01:16 AM rue_mohr: waaay overkill
01:16 AM rue_mohr: just a mcp6002 with a 3db gain
01:16 AM rue_mohr: their all amplified speakers
01:16 AM rue_mohr: the line level just isn't strong enough
01:19 AM AchiestDragon: ho , im using a 200w rack mount sterio referance amp , and a pair of floor standing tdl towers , but thats a bit more than 3db
01:19 AM rue_mohr: what I need is an inline +3db on the line levels going into it
01:19 AM rue_mohr: 3 will be enough
01:22 AM AchiestDragon: this i find gives good qualaty audio and gives you that bit extra volume but you need batteries or a verry smoth dc supply so you dont get hum or swtich mode psu noise , especialy when driving half decent studio headphones that are ususaly 36ohm
01:24 AM AchiestDragon: its why theres so many of this type of kit on ebay http://maker-works.com/wp-content/uploads/2013/05/blueEnclosure.jpg
01:25 AM rue_mohr: because there are lots of stupid people out there
01:28 AM AchiestDragon: yea most lin amps are not raited good enough to drive speakers , dew to rms v peek figures ,, a amp with a spec of 1.2w peek to drive speakers that need 1.2w rms is the 3db loss factor anyway
01:30 AM rue_mohr: their amplified speakers
01:30 AM AchiestDragon: the other factor is mipedance and power driving a load of that impedance in ohms
01:30 AM rue_mohr: their amplified speakers
01:30 AM AchiestDragon: yea most are
01:30 AM rue_mohr: one is the speakers in my monitor
01:31 AM rue_mohr: the other is a whole amplifer futz, with a car amp acting as a sub, and some amplified walkman speakers acting as fronts
01:31 AM AchiestDragon: ho so is it only a mixer amp you need on the line in
01:32 AM rue_mohr: no, just a boost
01:32 AM rue_mohr: casue for whatever reason some of the deivces just wont put out enough signal
01:32 AM rue_mohr: even when the volumes are maxed out
01:48 AM AchiestDragon: http://www.circuitlib.com/images/tutorials/4_audio_mixer.jpg , use just one resistor on each chan input with a 10uf cap in series with it and change c7 & c10 to 10uf i would also use a low noise fet dual opamp for better audio quality
01:49 AM AchiestDragon: +- 15 specified but you should also get it to worl with +-9v (+9v 0 -9V)
01:51 AM AchiestDragon: replacing r8 a/b with 100 k sould give you a wider gain range also
01:52 AM AchiestDragon: once you have the needed gain mesure it and use fixed value resistor
01:59 AM AchiestDragon: since there powered speakers yuor using if there not just a single chip amp and have a opamp drive with a feedback resistor like r8 on that scematic then changing that will mod the speakers to give you a diferent line input gain above the limit of what the var resistor on the input will allow , by changeing the gain of the amp not the range of the input
02:02 AM AchiestDragon: using 10uf caps give the amp a better low freq responce especialy if they sound "tinny" thats also ususal
02:04 AM AchiestDragon: using ultra low noise opamps will remove all the back ground hiss you get running it at "high volumes " although they cost a few cents more
02:07 AM AchiestDragon: idealy you should have 600r line matching transformers on the inputs and outputs if mains hum is a problem
02:12 AM AchiestDragon: and i would also put 100uf smothing caps in parralel with c6 and c9 to give the supply voltage more stabilaty on music peeks giving it a better thd figure
02:14 AM AchiestDragon: remeber c9 is a -v so get the polaraty right
02:23 AM rue_bed: I want to use it on usb power, and 3db is all I need
02:23 AM AchiestDragon: some pro audio uses 48v peek to peek line btw but dont struggle tring to get to work using 2.5v 0v -2.5v derived from 5v eather use a voltage inverter to give you a -5v , alternativly use a rs232 type +-12v voltage inverter chip they work from a singl 5v input
02:23 AM rue_bed: I use a pair of modem transformers for isolation
02:24 AM rue_bed: yea, but casue the levels in are low, 2Vpp out isfine
02:24 AM rue_bed: I have some MCP6002 rail-rail amps
02:25 AM rue_bed: low voltage, iirc 6V max
02:29 AM AchiestDragon: https://uk.rs-online.com/web/p/dc-dc-converters/6618436/
02:32 AM AchiestDragon: even 5v 0 -5v would be beter , for the opamp power , 2.5v is going to clip and limit it 5v in from usb and a use a voltage dubbler type circut to give you -5v also ,
02:36 AM AchiestDragon: i konw the spec says 1v pep on line but it depends on load and the input to an amp is ususaly 10k if theres a volume pot on it like most consumer stuff
02:38 AM AchiestDragon: the half decent audio codecs on some kit beleve it or not does have a way to check the load impedance so as beeing able to decide if its driving a line input or headphones , and switches the drive level accordingly
02:40 AM AchiestDragon: the threashold is arround 1.5k one the ones ive seen data for
02:43 AM AchiestDragon: but thats on headphone /line outs , not line out only outputs , the line outs often have a beter noise figure but are more often .8v peek to peek not 1v as a result (yet another drm enfoeced restriction to degrade level for copy prevention apparantly )
02:49 AM AchiestDragon: masked by the other advantage of letting them reduce the standard by .4v to save them having to have to use a higher audio psu voltage for the analog audio , faling to accept that the ouput is not line level standard anymore as drm changed it for them
03:00 AM anonnumberanon: man apparently the guy with the rooster robot makes his own servos
03:00 AM anonnumberanon: must dig into this
03:04 AM Kristjan: My name is Kristjan Robam. Bank account nr: EE671010010225901016 (SEB Estonia). People, please donate me with 200$ donates. I am very ill and need to collect money.
03:51 AM Triffid_Hunter: AchiestDragon: I think you'll find that 48v is phantom power for microphones, and the actual AC signal level is still in the tens of millivolts range
05:16 AM anonnumberanon: bingo https://pbs.twimg.com/media/DH500f1VoAEn2Cs.jpg:large
06:06 AM goodboy2017: i would like to learn
06:06 AM goodboy2017: can you teach me errything you know?
06:25 AM Snert: Yes, but I only have 5 minutes. That oughtta cover about everything I know :)
06:33 AM goodboy2017: ok
06:48 AM anonnumberanon: lol
06:48 AM anonnumberanon: sure goodboy2017 stick around
06:48 AM anonnumberanon: ask questions
06:50 AM Riemann: any IRC channel for control-systems?
06:50 AM Riemann: or motor drives/control or motion control?
06:54 AM Snert: we all love those subjects - but specific channel might be like #reprap for 3d printing. Those motors and control.
09:06 AM rue_mohr: what rooster robot?
11:03 AM SomeT: does anyone here use ARIA? http://robots.mobilerobots.com/wiki/ARIA
06:37 PM LuminaxWk is now known as Luminax
08:09 PM Tom_L: rue_mohr, got the plate for the table today: http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Mill_Mockup1.jpg http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Mill_Mockup2.jpg http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Mill_Mockup3.jpg
08:18 PM rue_mohr: why did I buy differential amplifiers?
08:18 PM Tom_L: why did you?
08:18 PM Tom_L: you must have had a reason..
08:18 PM rue_mohr: wow nice plate
08:19 PM rue_mohr: I dont know, I'm hoping you might know
08:19 PM Tom_L: surplus scrap
08:19 PM Tom_L: 1.25/lb
08:19 PM Tom_L: cheap
08:19 PM rue_mohr: I remember needing them, but I cant remember what for
08:19 PM rue_mohr: its steel, isn't it?
08:19 PM Tom_L: i honestly thought that would cost _alot_ more
08:19 PM Tom_L: no it's aluminum
08:19 PM rue_mohr: oh
08:19 PM Tom_L: steel would have been cheaper
08:19 PM Tom_L: but i have no way to work with it really
08:20 PM Tom_L: maybe this one will build the next one
08:21 PM Tom_L: it looks nice and flat too
08:21 PM Tom_L: i need to find a better straightedge
08:22 PM Tom_L: it's not quite 1" thick
08:22 PM Tom_L: but it's all they had today
08:22 PM rue_mohr: 25mm?
08:23 PM rue_mohr: ok, what parts do I need for a 12' mecha that I can get from china
08:23 PM Tom_L: i didn't check it but looks around .800 - .900" thick
08:23 PM Tom_L: plenty thick
08:24 PM Tom_L: for what i'm doing
08:24 PM Tom_L: i may add more bracing to the frame as the project progresses
08:28 PM rue_mohr: something I needed a differential output amplifier for
08:58 PM rue_mohr: !!! I know what it was
08:58 PM rue_mohr: it was an amp for using the cdrom motor as a rotation sensor
09:35 PM goodboy2017: banged ya mum last night at me mates house
09:35 PM Gene_home: Triffid_Hunter: you around?
09:35 PM goodboy2017: just knew you were here so i wanted to tell ya
09:35 PM goodboy2017: can see ya right now
09:35 PM goodboy2017: im new to these people , but not you Gene_home
09:36 PM goodboy2017: NOT YOU
09:46 PM -!- #robotics mode set to +o by ChanServ
10:01 PM Gene_home: hand clap!
10:11 PM Tom_L: he's not banned
10:12 PM Tom_L: yet..
10:34 PM rue_mohr: so I'm noticing a thing on aliexpress
10:35 PM rue_mohr: item on sale, sale ends, price goes up, item goes back on sale for more
10:38 PM Tom_L: rails should be here tuesday
10:38 PM Tom_L: pulleys for Z friday
10:40 PM Tom_L: may make a couple design changes
10:41 PM rue_mohr: hows that PC817 relay driver working?
10:48 PM anonnumberanon: rooster leghorn robot
10:48 PM anonnumberanon: on youtube
10:48 PM anonnumberanon: he's got some mad home-made servos on there
10:49 PM anonnumberanon: if you find his youtube channel and follow his twitter account link and then scroll down to the bottom there are very detailed high quality pictures of some of the components and the general design of the servos too
10:50 PM anonnumberanon: carbon fiber plates
10:50 PM rue_shop3: anonnumberanon, well link to one of the damn ones so I dont get the wrong thing
10:50 PM anonnumberanon: everything aluminum CNC'ed
10:52 PM anonnumberanon: https://www.youtube.com/watch?v=v_BgClI-AI4&t=2m3s
10:52 PM anonnumberanon: that's an intro to the guts
10:52 PM anonnumberanon: then there's his twitter account that has pics
10:53 PM anonnumberanon: for instance: https://pbs.twimg.com/media/DFCDd0VV0AE-i0u.jpg
10:54 PM anonnumberanon: that would be a diy servo in the center with the cyclinder coming out of the gearbox, it spins the entire torso, the section under it is the hips section
10:58 PM LuminaxWk is now known as Luminax
10:59 PM anonnumberanon: https://pbs.twimg.com/media/DFCBpErUwAAQtyB.jpg
11:07 PM AchiestDragon: i know that sort of thing is big in japan , you cant realy tell if its a personal project or the result of a team effort producing bits profesionaly for him
11:15 PM Gene_home: good lord!!!
11:16 PM AchiestDragon: it seems to be getting close to beeing a modern day national sport over there
11:28 PM AchiestDragon: i still have the book beleve it or not ,, well my son has it now http://cyberneticzoo.com/tag/david-l-heiserman/ i never built it but it was 8085 based , and programs entered in binary on a switch pannel like the old minicomputer front pannels
11:31 PM anonnumberanon: I don't understand how this is not catching on in America. But then again fighting robots have always been mainly an Asian thing (mostly Japan, now S.Korea going in full steam).
11:31 PM AchiestDragon: back in those pre interent days sourcing some of the parts was just about impoisble
11:32 PM anonnumberanon: I don't think anyone else but him is building that rooster robot he's been at it for years and years.
11:33 PM AchiestDragon: well not just fighting robots , the other compertitions like micromouse , again the japanise seem to have a big following and take an interest , but think its just the western "its a geek thing " attitued that dosent get it promoted
11:33 PM anonnumberanon: He says his servo controller leaves to be desired though and you can tell when he fights (like this year's championship where he got somewhat massacred) that his IMU integration is not very good and his fight moves leave a lot to be desired as far as range and stability.
11:34 PM anonnumberanon: I looked it up it uses some weird microcontroller running at 60 Mhz.
11:37 PM AchiestDragon: the best we got was robot wars , and to be honest thats just basicaly a radio controled version of banger racing than anythign realy robot orientated
11:38 PM anonnumberanon: I understand the interest in Robot Wars but I much prefer this type because of the challenge of keeping a biped standing and making it move.
11:39 PM AchiestDragon: i tend to be a bit picky , if its user controled by rc then its rc animatroincs not atuonomus robotics
11:40 PM anonnumberanon: yeah i love both but autonomous is definitely a lot slower and harder to watch as a sport
11:40 PM anonnumberanon: imo
11:41 PM AchiestDragon: https://www.youtube.com/watch?v=XF4jExjWl50
11:42 PM anonnumberanon: here it is, that controller board https://translate.google.com/translate?hl=en&sl=ja&u=https://www.vstone.co.jp/products/vs_rc003hv/download.html&prev=search
11:43 PM anonnumberanon: with an NXP microcontroller
11:46 PM anonnumberanon: arm 7 LPC2148 i believe
11:48 PM anonnumberanon: AchiestDragon, do you win stuff with that micromouse contest?
11:48 PM rue_mohr: oh it is that one
11:48 PM AchiestDragon: hmm and im looking at 2 rpi3's and 4 stm32 control boards for the controls so far ,
11:49 PM anonnumberanon: AchiestDragon, controls of what, you got a project running?
11:49 PM rue_mohr: its not catching on in america cause of the lure of being dumb fat and drinking while watching tv
11:50 PM anonnumberanon: damn that micromouse is very impressive
11:50 PM AchiestDragon: anonnumberanon: ists more of a student compertition so an award but not prize money for micromouse as im aware , unless theres side bets and stuff going on
11:51 PM rue_mohr: anonnumberanon, you know whats neat, is the cnc machines I have could do those parts, that inspiring
11:51 PM anonnumberanon: rue_mohr, oh this? http://digitalspyuk.cdnds.net/17/17/768x319/gallery-1493134203-wall-e-lazy-humans.jpg
11:51 PM anonnumberanon: heh
11:52 PM anonnumberanon: yes rue_mohr
11:52 PM anonnumberanon: either i can build a cnc machine or you can make me servos
11:52 PM anonnumberanon: :)
11:52 PM anonnumberanon: but then I'd have to return the favor
11:52 PM rue_mohr: I think I just blew another few hundred dollars on aliexpress
11:52 PM rue_mohr: damnit
11:53 PM anonnumberanon: my man
11:53 PM anonnumberanon: did you get like a few million components
11:53 PM rue_mohr: a freaking truck is gonna come by and drop off all the components in china
11:53 PM AchiestDragon: the project im working on is a hexapod atm , and its still on the drawing board so to speak https://drive.google.com/file/d/1VK2HVKvYFvmoDi_VtZq2-hQpyE0S5Nn2/view?usp=sharing
11:53 PM rue_mohr: I'v not cntinued on my hexapod
11:54 PM rue_mohr: wtf di I call it
11:54 PM rue_mohr: I'v not eaten yet, I'm starting to shake
11:54 PM anonnumberanon: rue_mohr, anyways I'm studying the best source for a good motor, cheap and strong, 9V, then the gears needs to be sorted out, and machining the aluminum cases luckily is diy
11:54 PM rue_mohr: http://ruemohr.org/~ircjunk/robots/frankenhex/p1090284.jpg
11:54 PM AchiestDragon: i need to get hte 3d printer so i can at least build test actuators to see how well they perform before going further
11:55 PM rue_mohr: I'm curious to know if it wil be able to stand
11:55 PM rue_mohr: but I just spent prolly $50 alone on parts I can use for the air muscles for the 12' mecha
11:56 PM anonnumberanon: oh yeah i forgot about your spider rue_mohr
11:56 PM anonnumberanon: AchiestDragon, how do you plan on controlling your motors?
11:58 PM AchiestDragon: hbridge drivers , the motors are 12v 12000rpm batery drill type ones , with 3mm shafts so cooupling to m3 threaded bar for the acuators is easy enough , optical speed sensors and prob microswitch limit sensors , using the stm32 to control them