#robotics Logs
Aug 16 2014
#robotics Calendar
00:15 rue_mohr2 Mr_Sheesh, what are you up to?
00:15 rue_mohr2 looks like I might have nopbody show up for robotics tommorow
00:16 Mr_Sheesh Not much tonight, mostly a cat entertainment thing (laser, flying toy, and string thrower) other han some stuff that just bitbangs
00:16 rue_bed remind me what projects yo uhave going?
00:21 Mr_Sheesh Light tol to do IR thru UV illumination & sensing; some camping stuff for lighting etc.; Cat thing; some bioelectric stuff w/ one companym stalled atm; long list, chugging through them
01:14 rue_shop2 hmm
01:15 rue_shop2 last time I used bushings so the holes woulnd't be the worng size
01:15 rue_shop2 I drilled the shaft holes directly thru the thing this time
01:15 rue_shop2 and they are too big
01:36 rue_shop2 ok I know what I designed wrong
01:37 rue_shop2 hmm reworking it is the next problem
03:07 rue_shop2 I wonder how I stop the wrist from pivoting on the cross dowel
03:11 rue_shop2 heh, every joint on this robot is out by a few degrees
03:16 deshipu I always trim in software
03:19 rue_shop2 yay, I finished the yaw/pitch assembly!
03:21 rue_shop2 er, pitch roll really
03:25 deshipu do a barrell roll
03:25 deshipu you roll a camera?
03:29 rue_shop2 the robots gripper
03:30 rue_shop2 http://ruemohr.org/~ircjunk/robots/arm4/p1010683.jpg
03:30 rue_shop2 a mechanism similar to that
03:30 rue_shop2 (I did this one differently)
03:30 rue_shop2 I think I want to do the next one 100% cables
03:36 deshipu ah
03:37 deshipu hmm, there is something called slip ring for rotating with cables
03:37 deshipu s/cables/wires
03:37 rue_shop2 yes, but the contacts tend to 'grind' so they are no good for anything other than power
03:38 deshipu I see
03:39 Triffid_Hunter use induction to pass signals over a slip ring
03:40 deshipu I wonder when someone will kickstart a bluetooth servo ;)
03:40 rue_shop2 they exist, they cost $3000ea, just like all the other silly servo designs
03:41 deshipu who buys that?
03:44 deshipu rue_shop2: do you have any particular use in mind for your arms?
03:44 rue_shop2 universities
03:44 deshipu rue_shop2: we have a chess-playing robot on the backburner
03:44 rue_shop2 not yet
03:44 rue_shop2 but everythign I tried to think of required more than one
03:44 rue_shop2 so I'm building an army
03:44 deshipu \o/
03:45 deshipu world domination, I see
03:45 deshipu I need to hurry
03:49 rue_shop2 I suspect if I'm clever I can make a supper assembly line
03:49 rue_shop2 oh ohoho oh, I can make a COOKIE assembly line!
03:49 rue_shop2 screw supper!
03:49 rue_shop2 oh,.... damn. wait.... I'v not had supper
03:49 rue_shop2 damn its 1:30am
03:51 rue_shop2 ok, well, all the upper arm peices are here, they just need to be assembled
04:03 Tom_itx mmm cookies...
04:04 rue_mohr2 think I could make a thru-feed oven for cookies?
04:04 deshipu I'm asking because sometimes knowing the use case lets you pick better materials
04:04 rue_mohr2 na, I just use what I have
04:04 Tom_itx rue_mohr2, why not?
04:05 Tom_itx use toaster oven elements
04:05 rue_mohr2 I think I can do the next arm with cables and pullies
04:05 rue_mohr2 hmm
04:05 rue_mohr2 make a long oven
04:05 deshipu rue_shop2: a robot arm for placing elements and solder paste, and an oven for baking that :D
04:05 Tom_itx wonder what you'd use for a belt
04:05 rue_mohr2 how long cookies need to bake for?
04:05 rue_mohr2 Tom_itx, easy, high temp silicone
04:05 Tom_itx til they're done
04:06 deshipu hmm, color sensor?
04:06 deshipu or poke them with a needle?
04:06 rue_mohr2 if I find soemthing round with the right circumfrance, and lay an even coat of silicone on it, let it set, and peel it off
04:07 rue_mohr2 hah, each robot could just have its own toaster oven
04:07 rue_mohr2 trays that do one cookie at a time :)
04:07 Tom_itx rotary
04:07 Tom_itx then you could spin it til they're done
04:08 rue_mohr2 heh, carosele oven
04:08 Tom_itx open out the bottom and let the cookies drop out
04:08 rue_mohr2 Tom_itx, its freaking 2am, go to bed
04:08 Tom_itx 4am
04:09 deshipu 10am
04:09 deshipu hmm, 11 actually
04:12 rue_bed http://scp-wiki.wdfiles.com/local--files/warning-labels/spc_spacetime.png
06:21 deshipu I just made my breakout board for arduino pro mini 4x smaller: https://lh5.googleusercontent.com/-EHBTkWVA0B8/U-8u-9wWoMI/AAAAAAAACCo/UJSg20K31sQ/w752-h535-no/board.png
06:21 deshipu the trick is to solder the pins on the other side ;)
11:10 rue_mohr2 :) nice
11:10 rue_mohr2 you shoudl overhang it off the end for the power in connections
11:10 rue_mohr2 deshipu,
11:10 rue_mohr2 you can get smt headers too
11:12 rue_mohr2 hmm, if you take account of the pins, you can prolly overlap the arduino power pins to the traces on it
11:12 rue_mohr2 hmmm
11:12 rue_mohr2 if the power is clean enough
11:15 rue_mohr2 using long pin headers would help the idea
11:23 rue_mohr2 aparently I havnt' used my ik lib on a robot yet!
11:23 rue_mohr2 }:) this will be some fun
11:24 rue_mohr2 len = dist3d(dist p1x, dist p1y, dist p1z, dist p2x, dist p2y, dist p2z);
11:24 rue_mohr2 angle = elbow(dist d, dist l1, dist l2);
11:24 rue_mohr2 angle = dir(dist x, dist y);
11:25 rue_mohr2 the eblow is for triangle solving
11:26 rue_mohr2 if you have an arm like L it tells you the angle to set the joint to so that the distance between the endpoints is what you want
11:27 rue_mohr2 hmm, I can make a library for SCARA arms.... just fill in the numbers and go
11:28 e_mohr2 starts building a cartesian plan
11:29 rue_mohr2 hmmm where is 0,0,0
11:30 rue_mohr2 bottom of the middle of the base
11:30 rue_mohr2 wait, maybe it should be 10cm above that
11:30 rue_mohr2 hmmm
11:30 rue_mohr2 ok, Z is up, check
11:31 rue_mohr2 X.... WHERE IS X!!!????
11:31 rue_mohr2 ok, its ok, I'll start with Y
11:31 rue_mohr2 OH MY GOD i DONT KNOW WHICH WAY Y SHOULD BE, up... maybe up...
11:31 rue_mohr2 AAAH I already HAVE AN UP!
11:31 rue_mohr2 damnit, this is harder than I thought
11:32 rue_mohr2 ok, ok wait
11:32 rue_mohr2 I'v got it
11:32 rue_mohr2 with the base servo centered, +-X is left/right
11:32 rue_mohr2 AAAAH, +-, I forgot! which way is + !!! ARG
11:33 rue_mohr2 ok, its ok, + will be away from the robot
11:33 rue_mohr2 no, wait that dosn't work, AAAAAAH
11:33 rue_mohr2 ok wit I need something to ref this with
11:34 rue_mohr2 I know, I'll arbitrarily pick something
11:34 rue_mohr2 I'll make a gun with my right hand and the directions my fingers point will be +
11:34 rue_mohr2 a machine gun with a nice long handle
11:35 rue_mohr2 with a hammer trip on the top, western style...
11:36 rue_mohr2 so, my thumb is Z, this works, it pointing up
11:36 rue_mohr2 +X is to the left, hmm
11:36 rue_mohr2 I think I'll do this with my left hand
11:36 rue_mohr2 +X is to the right...
11:36 rue_mohr2 +y is forward of the robot
11:37 rue_mohr2 yea, I can live with that
11:37 rue_mohr2 hmm how many segments on the robot
11:37 rue_mohr2 one that goes up
11:37 rue_mohr2 then two arm segments
11:37 rue_mohr2 then a gripper segment
11:38 rue_mohr2 oh, hmm
11:38 rue_mohr2 where is the end of my arm...
11:43 rue_shop2 damnit, arm 7 has almost a redundant axis how its set up
11:43 Tom_itx X is left to right
11:43 Tom_itx Y is front to back
11:43 Tom_itx Z is up and down
11:43 Tom_itx A is rotary about X
11:43 Tom_itx B is rotary about Y
11:44 rue_shop2 ya know, you just reminded me I have a whole ABB 1400 manual
11:44 rue_shop2 ... set
11:47 rue_shop2 hmm should I code or build
11:48 rue_shop2 the last bits of arm 8 should be really easy
11:48 rue_shop2 hmm I wonder how I'm gonna deal with redundant axies
11:48 rue_shop2 the wrist on arm7 is so long its almost a while linkage
11:49 rue_shop2 dont think I like that way of doing a wrist
11:49 rue_shop2 AND NOW i KNOW!
11:49 Tom_itx here comes arm8
11:51 rue_shop2 tom, almost finished 8, 9 will be like 4 and 8 but cable driven
11:51 rue_shop2 7 contributed a gripper design
11:51 rue_shop2 and I might redo that base style
12:00 deshipu rue_shop2: I plan to have a jumper connecting the power pin of the arduino with the power
12:00 deshipu rue_shop2: this way I can disconnect it for programming
12:01 rue_shop2 yup
12:02 rue_shop2 motor disable on a robot is a really good thing
12:02 rue_shop2 (thats by experience)
12:09 rue_shop2 ok I think I standardized the gripper bolt pattern
12:10 rue_shop2 hmm looks like I didn't save it
12:13 rue_shop2 looks like its a 20mm hexagon
12:16 Hyratel rue_shop2, yeah. ESTOP is important
12:16 deshipu Hyratel: a big red button? :D
12:17 Hyratel well, I'm using the SYSTEM button on an X360 wireless controller
12:19 Hyratel very handy for a vehicle though I dislike the asymmetry of the Xbox family controllers
12:19 Hyratel jopystick asymmetry
12:20 deshipu they had a 50kg robot somehow inherited from ESA at my university
12:20 deshipu 50kg of lift
12:21 deshipu it was connected to a windows 95 box, and would start thrashing around the whole room when it hung
12:21 deshipu so there were big red buttons every 3m all around the room
12:22 deshipu they used it for holding a camera for scanning maps
12:22 deshipu because it was the only robot precise enough for that
12:23 deshipu Hyratel: I bough a cheap chinese clone of the sixaxis controller, and then it turned out that the linux library can only support the original one
12:24 deshipu and nobody is working on that lib anymore
12:31 Hyratel :\
12:31 Hyratel can i get a context on the sixaxis?
12:33 Hyratel oh. PS3 sixaxis
12:34 Hyratel can you compare the datastream?
12:36 deshipu I didn't have time to look into it
12:36 deshipu it seems that the library just has some ids and stuff hardcoded
12:37 deshipu it's a bluetooth device, and I'm not very familiar with how that works in linux
12:38 deshipu the nice thing about sixaxis, potentially at least, is that you could also use the position of the whole controller for more degrees of control
12:41 deshipu and it's wireless, so look ma, no cables
13:03 rue_shop2 see almost done
13:03 rue_shop2 er
13:03 rue_shop2 weee almost done!
13:18 rue_shop2 I also have to work on reduced peice count
13:19 deshipu peice count?
13:19 rue_shop2 I have about 150 peices in this new arm
13:20 rue_shop2 but the important thing is to keep the custom peices down
13:20 rue_shop2 most of the 150 is bolts and nuts
13:20 rue_shop2 putting lots of those into a robot is ok
13:20 rue_shop2 300 custom cams isn't ok
13:26 rue_shop2 yay, 2 belts and then I just have to tidy it up
13:27 rue_shop2 oh, and counterweight it
13:47 rue_shop2 one belt finished
14:02 rue_shop2 yay!
14:02 rue_shop2 now its just tuning and cleanup
14:05 deshipu pieces?
14:06 rue_shop2 I have a few spacers to put in, need to shrten up the shafts
14:06 rue_shop2 counterbalancing
14:06 deshipu I'm making room for a capacitor on that board :)
14:07 GargantuaSauce <deshipu> it was connected to a windows 95 box, and would start thrashing around the whole room when it hung
14:07 GargantuaSauce this is the stuff nightmares are made of
14:08 rue_shop2 *windows* says it all
14:08 deshipu yup
14:08 deshipu you really want a real-time system for this kind of stuff
14:08 deshipu one loose interrupt and it all goes bananas
14:08 GargantuaSauce well a lot of the machine tools out there run xp i think
14:09 GargantuaSauce pretty sure the key is having more failsafe mechanisms than an oh-shit-button
14:10 rue_shop2 w95, the os that cant even stay running for 60 days in a row
14:10 rue_shop2 60?
14:10 rue_shop2 what was the clock rollover that cause an automatic crash, I forgot
14:11 deshipu 80
14:11 deshipu afaik
14:11 deshipu but I think they fixed it in some update
14:12 rue_shop2 I thought it was discovered publically just as 98 was on its way out
14:14 rue_shop2 I think I'll use hobby servos for arm10 and then go to custom servos
14:15 deshipu have you tried threaded rods on motors yet?
14:16 deshipu like Prusa Mendel has for the vertical axis
14:16 rue_shop2 yea, WAY too slow
14:16 rue_shop2 I have a few things built like that
14:17 deshipu pneumatic made out of plastic bags? :D
14:17 rue_shop2 uh, got images of that one?
14:17 deshipu that was long ago, not sure they are on the internet
14:18 deshipu http://www.instructables.com/id/Soft-Robots-Making-Robot-Air-Muscles/
14:18 deshipu that looks fun
14:18 deshipu but the one I saw was just a plastic bag between two wooden planks
14:18 deshipu on a hinge
14:19 deshipu like \o/
14:19 deshipu building a soft robot octopus would be awesome
14:21 deshipu this stuff has probably all the imaginable disadvantages :)
14:26 deshipu debugging leaks must be lots of fun
14:27 MrCurious1 so there is a solar flare due to hit on the 18th. https://twitter.com/TamithaSkov/status/500444222139281409 i fly on the 19th. wonder how that is going to go down
14:29 deshipu MrCurious1: ouch
14:29 deshipu MrCurious1: I travel tomorrow, but trains are hopefully less suspectible ;)
14:34 Tom_itx rue_shop2, use threaded rods with a high pitch
14:34 Tom_itx like 5 tpi
14:34 Tom_itx acme
14:35 Tom_itx ballscrew
14:35 Tom_itx etc
14:35 MrCurious1 false alarm
14:44 GargantuaSauce http://ca.mouser.com/ProductDetail/Cree-Inc/CAS300M12BM2/?qs=0kFKDc1CZSnwIPwC%2f%252bflVg%3d%3d
14:44 GargantuaSauce do want
14:48 MrCurious1 1200V, 300A
14:48 MrCurious1 sir, what is your intended use?
14:49 MrCurious1 going to add offensive capabilities to your hex?
14:49 MrCurious1 because 1200V, 300A scares the piss out of me
15:12 deshipu http://paste.sheep.art.pl/b5a56984-ee21-4dd3-b3c1-3a3a469e4dde/%2Binline <-- I think I will leave it like this
15:13 deshipu the two pins next to the jumper will need to be shorted too, but I think I will use a 3 goldpin socket for that
15:14 rue_shop2 I suppose I can make 5tpi acme screws now cant I?
15:15 GargantuaSauce ya scaling up to 500kg and making it gallop like a goddamn horse
15:15 rue_shop2 I dont do quadropeds
15:15 MrCurious1 GargantuaSauce: i would pay a dollar to see that
15:15 GargantuaSauce how about $50k
15:15 deshipu I always wanted to ask this
15:16 deshipu what does ACME mean?
15:16 GargantuaSauce it's a brand
15:16 MrCurious1 its a company
15:16 deshipu I see it all over the roadrunner cartoons
15:16 MrCurious1 that got latched onto by cartoons....
15:16 MrCurious1 wonder if ACME paid for that placement or got it for free
15:16 MrCurious1 as that was far ahead of product placement
15:16 deshipu it's a mixed blessing
15:17 deshipu they always malfunction
15:17 MrCurious1 no. that was user error. the coyote was grossly incompetent
15:17 deshipu rue_shop2: a threaded rod for the gripper would be nice, because then you can rotate it too
15:18 deshipu you know, the two gears and a screw design, )|(
15:18 deshipu MrCurious1: they always say that
15:18 deshipu MrCurious1: but maybe the instruction manual was wrong?
15:20 GargantuaSauce he was purchasing QA failures at rock-bottom prices from an unscrupulous warehouse worker
15:21 MrCurious1 wonder what the coyote is up to these days...
15:21 deshipu they don't have very long lifespans
15:21 deshipu especially if they consistently fail to catch prey
15:22 MrCurious1 so he probably died, got turned into poop, which got eaten by bugs and turned into bug poop, and so on
15:24 MrCurious1 http://www.ebay.com/itm/Aluminium-Hexapod-Robotics-Spider-Six-6DOF-Biped-Robot-Kit-with-Clamper-Gripper-/251619204729?&_trksid=p2056016.m2518.l4276
15:24 GargantuaSauce ive been tempted by a bunch of those
15:25 GargantuaSauce they all put 100% of the knee joint strain on the servo spline though
15:25 GargantuaSauce and i dont think that is really kosher
15:26 GargantuaSauce bbl
15:28 deshipu I wonder if adding a spring for balancing against the force of gravity would help
15:28 deshipu kinda like a counterweight
15:29 deshipu so that with no power in the servos it's standing still, and you need equal power to move up and down
15:30 MrCurious1 yeah
15:31 deshipu I have to experiment with rubber bands on my mini quadruped
15:32 deshipu most force is on the middle joint most of the time
15:40 rue_shop2 ok, gripper counterweight is there, its a guess, but .. its there
15:41 rue_shop2 dont' come assembled eh?
15:41 deshipu well, you have to put your own servos
15:41 deshipu and brains
15:42 rue_shop2 yea
15:42 rue_shop2 they do that whole side force thing to the servos I hate so much
15:43 deshipu I know that with the quality of code that I can write, any legged robot will be much much worse than a simple wheeled one, but I'm still fascinated by walking
15:43 rue_shop2 its that reason I build arm7
15:43 rue_shop2 to show how to make a proper freaking rotary base for a hobby servo arm
15:43 deshipu I think they do have this nub on the other side
15:43 rue_shop2 $50 in servos
15:44 rue_shop2 no its all hanging off the horn
15:44 rue_shop2 its better than most, but its still doing it
15:44 deshipu ouch
15:45 rue_shop2 its a nice build tho!
15:45 deshipu I have the bearings and the metal parts to add to my robot on the other sides of the servos
15:45 rue_shop2 I wonder what kinda cutter it was done with
15:45 deshipu but I'm still thinking about how to attach them
15:45 MrCurious1 pic?
15:45 rue_shop2 tell me about what you want to build
15:45 deshipu I guess I will glue them
15:46 rue_shop2 http://ruemohr.org/~ircjunk/robots/arm8/p1060552.jpg
15:46 rue_shop2 I'll do an update in a few hours
15:46 rue_shop2 the whole top is assembled
15:46 deshipu http://letsmakerobots.com/files/userpics/u22498/IMG_20140806_190624.jpg <-- this is what I have now
15:47 MrCurious1 rue: you soooo need a cnc or printer
15:48 deshipu rue_shop2: do you keep them all, or do they get disassembled for parts?
15:51 rue_mohr2 no I dont
15:51 rue_mohr2 looks like wood! :)
15:52 rue_mohr2 no robot has been turned into parts for antoher robot in a long time
15:52 rue_mohr2 and none of the robots that were finished have ever
15:53 rue_mohr2 I cant tell how long the last segment of the leg is???
15:53 deshipu it's changed now, about 7cm
15:53 deshipu on that photo it's probably 4cm
15:54 deshipu I'm going to make it between 5 and 6
15:54 deshipu based on the tests
15:54 deshipu http://letsmakerobots.com/files/userpics/u22498/IMG_20140806_190649.jpg
15:54 deshipu a little better photo
15:55 deshipu so yeah, I have those little bearings, and some more of those meccano parts
15:55 deshipu so the plan is to either make a hole in the servo case
15:56 deshipu and put a screw throught that, to attach the bearing (with some spacers)
15:56 rue_mohr2 are the servos glued? thats cheating :)
15:56 deshipu or just glue the bearing directly to the servo
15:56 e_mohr2 squ
15:56 deshipu yeah, they are glued, I couldn't figure out a better way to attach them without having a 3d printer or taking up lots of space
15:57 rue_mohr2 hmm interesting,
15:57 rue_mohr2 I suggest you try to catch the screw for the servo horn thru the meccano
15:57 rue_mohr2 it'll help with the rotation problem
15:57 rue_mohr2 does the top weigh much?
15:58 rue_mohr2 you at about $150 on that?
15:58 deshipu I really stopped counting :)
15:58 rue_mohr2 :) sometimes that helps
15:58 deshipu no, it's not very heavy, the wood is something balsa-like
15:59 deshipu a raspberry pi, lipo battery, some servo controller and ubec
15:59 rue_mohr2 about 5 years ago I paid $10 ea for the standard sized servos on those arms (7, 8)
15:59 deshipu quite light, the servos are the heaviest part
15:59 deshipu I had those for $5 a piece
15:59 rue_mohr2 do you have any control software working?
16:00 deshipu yes, I can walk around with a game pad
16:00 rue_mohr2 cool
16:00 deshipu or on its own, of course, but it only has one sensor now, and that's an accelerometer+gyro, and unused
16:00 rue_mohr2 are the kinematics pretty close?
16:00 deshipu they are worse now with the new servos
16:00 deshipu I need to sit down and trim it all properly
16:00 deshipu 3-4mm off
16:01 rue_mohr2 maybe your units/degree is out?
16:01 deshipu the fact that the legs are twisted by gravity doesn't help
16:01 rue_mohr2 yea, you need that rear bearing and a winder linkage
16:02 deshipu https://www.youtube.com/watch?v=cmEIybq4c5Y <-- this is it walking with the old servos
16:03 rue_mohr2 looks good, I recall this robot from long ago
16:03 rue_mohr2 did you do the ik from scratch?
16:03 deshipu yes
16:03 deshipu all software is from scratch
16:03 deshipu I'm a software guy
16:04 rue_mohr2 https://www.youtube.com/watch?v=PQicXbj5Ivs <-- thats what you get when you use an arduino for servo pulse control
16:04 rue_mohr2 ughkikg
16:04 rue_mohr2 I thik its only got like a 6hz update
16:05 deshipu yup
16:05 deshipu I have that problem with the small one too
16:05 rue_mohr2 https://www.youtube.com/watch?v=D8A0L2NXCvM
16:05 deshipu but I have some ideas for how to improve it
16:05 rue_mohr2 $$ and the kinematics are slightly out
16:06 deshipu phantomx is a little out of my legue :)
16:06 rue_mohr2 so far your kinematics look like they work better
16:07 deshipu well, arbotix use NUKE, so it's all a qestion how precise measurments you do and how well you calibrate it
16:07 rue_mohr2 I dont think analog servos are a problem if you pulse them properly
16:07 deshipu they have some windows gui app for doing the calibration
16:08 deshipu I hope to be able to do something like this with the gyro: https://www.youtube.com/watch?v=3Q0Lgf-Zaug
16:08 rue_mohr2 https://www.youtube.com/watch?v=jWP3RnYa_tw ooo kinematics,
16:08 rue_mohr2 oh wow, thats really done well
16:09 rue_mohr2 looks like a commercial kit tho
16:09 deshipu the frame, yeah
16:10 rue_mohr2 oo compensated, nice
16:11 deshipu not sure if it has pressure sensors in legs too
16:11 rue_mohr2 maybe its modified servos?
16:12 rue_mohr2 maybe I should tell you how to get torque feedback from servos without modifying them?
16:12 rue_mohr2 :/ I need to get buddy III going
16:12 deshipu I have to go to sleep
16:13 deshipu good night
16:13 rue_mohr2 2pm...
16:13 deshipu 11pm
16:14 rue_mohr2 its only 11pm and your going to be!!!???
16:15 deshipu train tomorrow at 6
16:15 rue_mohr2 I need a program to automatically close youtube ads
16:15 rue_mohr2 what you training for?
16:15 deshipu traveling back home
16:15 deshipu 12h ride
16:15 rue_mohr2 you should just do it, I'm sure you will be ok
16:16 deshipu and then I can work on actual physical robots again
16:16 deshipu I've been away for a week and just cleaned up my programs and played with cad
16:18 rue_mohr2 whats it written in?
16:19 deshipu python, mostly
16:20 deshipu the small one has a simple servo controller in arduino
16:20 deshipu just reading the positions from a serial
16:20 deshipu the big one runs python directly on rpi
16:21 rue_mohr2 how amny bytes of set a servo position?
16:22 deshipu right now I just went for quick and dirty and it's not even a full byte -- I send an integer in degrees
16:22 rue_mohr2 oh, and they are only 180 degrees
16:22 deshipu yeah
16:22 rue_mohr2 but to specify the servo?
16:22 rue_mohr2 or you write a whole set at a time?
16:22 deshipu I send 12 bytes
16:22 deshipu for 12 servos
16:23 rue_mohr2 how do you sync?
16:23 deshipu that's faster
16:23 deshipu 0xff as the first byte
16:23 e_mohr2
16:23 deshipu and if i get anything out of range, I skip to the next 0xff
16:24 deshipu this code is hairy and up for a rewrite though
16:24 rue_mohr2 I went heavy, 0xFF[8 bits servo number][16 bits position]
16:24 deshipu eventually I want to do ik on the arduino
16:24 rue_mohr2 but the position is used to about 12 bits
16:24 deshipu leg ik, at least
16:25 rue_mohr2 at 115200 baud, I can update faster than the servo cycle
16:25 rue_mohr2 oh that cant be right
16:25 deshipu yeah, that's another thing, I have this bluetooth serial module
16:25 deshipu and it defaults to 9600
16:25 rue_mohr2 oh it can, I only used 3 bits for the servo address, other bits say if its a cached or go position
16:25 deshipu I need to figure out how to configure it for more
16:26 rue_mohr2 I been working on setting up so I can write all the positions cached and then trigger than all at once
16:26 deshipu isn't that bad for the battery?
16:26 deshipu I mean, moving all at once
16:26 rue_mohr2 they dont, cause only one pulse it sent at a time
16:27 rue_mohr2 so, they spool out over the [8-16] ms
16:27 deshipu the reason I want to do leg ik on the arduino side is that then I can also do tweening in there
16:27 rue_mohr2 http://ruemohr.org/~ircjunk/robots/arm7/hobbydriver/
16:27 rue_mohr2 the timing is perfect
16:27 rue_mohr2 no stalls
16:28 rue_mohr2 m32 is overkill
16:28 rue_mohr2 its not possable to add any more interrupt sources without causing glitching **
16:29 rue_mohr2 *squint* its not finished yet?
16:29 deshipu I'm a big fan of single-threaded, cooperative multiprocessing :)
16:29 rue_mohr2 I'd like to get into fpga's and make a proper servo controller
16:29 deshipu rue_mohr2: well, it's finished as in it works, but I want to move some functionality from python to arduino
16:30 rue_mohr2 my cod
16:30 rue_mohr2 http://ruemohr.org/~ircjunk/robots/arm7/hobbydriver/main.c
16:30 rue_mohr2 the cache and enguage position code isn't written yet
16:31 deshipu I wouldn't know, I have very little experience with the relatively low level stuff
16:31 deshipu you know, I'm one of those hipster kid programming web apps
16:32 rue_mohr2 its all good
16:33 rue_mohr2 should i get the stuff I need to work on my vacuum former?
16:33 rue_mohr2 maybe I should get some more sleep
16:33 rue_mohr2 deshipu, do play with my code if you want
16:34 deshipu yeah, I will definitely analyze it once I'm not falling asleep
16:34 rue_mohr2 verry stable timeing
16:34 deshipu thanks
16:34 deshipu bye
16:34 rue_mohr2 looks like I kept the update rate constant across all the servos
16:34 rue_mohr2 gnight
20:00 anonnumberanon https://www.youtube.com/watch?v=uIlu7szab5I&feature=youtu.be
21:47 rue_house wow
21:47 rue_house ok, so,
21:47 rue_house 1) power outage
21:47 rue_house 2) I had the router half upgraded, so it booted into a new kernel that wasn't set up for the network cards it had
21:48 Tom_itx 12" water main broke here today
21:48 rue_house 3) when I put the right network cards in (100mb! now!) the kernel wasn't configured with the modules the firewall needed
21:48 rue_house ooo that sounds wet
21:48 Tom_itx closed 50 business's
21:48 rue_house did it eat out half a street?
21:49 Tom_itx we were driving by it as it was happening
21:49 Tom_itx at least half
21:50 rue_house I wonder if my internet will be faster with the new 100mbit interface
21:51 Tom_itx they supposedly doubled our rate recently
21:51 Tom_itx 50Mbit
21:51 rue_house the new arm is prettymuch finished
21:51 Tom_itx i updated mine a while back
21:51 Tom_itx seems faster
21:51 rue_house need to give it a controller
21:51 Tom_itx i think these boxes would cost too much to ship / value gained
21:52 Tom_itx especially since you're acustomed to getting stuff free
21:55 rue_house do tell about them
21:55 Tom_itx not alot to tell
21:55 Tom_itx you've seen most of it
21:56 Tom_itx i'm not quite done sorting yet
21:58 rue_house well it says I get 16mbits download, so I should see a slight improvement
21:58 Tom_itx my upload is crap
21:58 Tom_itx the download is slightly better than it was
22:00 Tom_itx this isn't the best pc to run a test on
22:00 Tom_itx it's good for irc and that's about it
22:00 rue_house heh
22:00 Tom_itx i got 15.8 just now on it
22:01 rue_house an old welder chap I knew passed away yesterday
22:01 Tom_itx always sad
22:01 Tom_itx an old friend of mine passed this summer
22:01 rue_house world is getting smaller!
22:01 rue_house ok see if internet in the shop works
22:02 rue_house there were two 10mbit interfaces on the machine, so I should be able to transfer stuff between house and shop faster now
22:02 Tom_itx no hardwire between them?
22:03 Tom_itx i got another spool of wire the other day to run a couple
22:03 rue_shop2 hey looka me I'm online
22:03 rue_shop2 the router has 3 ports
22:03 rue_shop2 internet, shop, house
22:03 rue_shop2 shop house are seperate networks
22:03 Tom_itx put a switch on it
22:04 Tom_itx i get 62.3 on the other pc
22:04 rue_shop2 this is good tho, its one more thing off my todo list
22:05 rue_shop2 I'm on fiber now
22:05 Tom_itx life is still on my todo list
22:05 rue_shop2 so I get 5mbits up
22:05 Tom_itx i get 6.9 up
22:05 rue_shop2 I'm thinking once a year I should go thru all the machines
22:05 Tom_itx not sure what the advertised is
22:05 rue_shop2 vacuum them and stuff
22:05 Tom_itx i do that
22:05 Tom_itx air compressor
22:06 rue_shop2 its aparently been atleast 4 years since I was in that machine
22:06 rue_shop2 I build them as appliances, set and forget
22:07 Tom_itx wound up working today
22:07 rue_shop2 short day?
22:07 rue_shop2 ok I want to port the m32 servo controller to the m328, but need to set up the laundry first
22:09 Tom_itx name change a couple registers and you should be done
22:14 rue_shop2 I used timers in fancy ways, we shall see
22:16 Tom_itx there are more register names on the 328 because of the additional feaures it has
22:16 Tom_itx the code should still work ok
22:16 Tom_itx with minor mods
22:18 rue_shop2 drat, I missed the movie
22:26 rue_shop2 I'm gonna get myself into a back port mess...
22:26 rue_shop2 oh well
22:28 Tom_itx you live for messes
22:29 rue_shop2 sometimes the only way to know it to spead it out and see if repair is feasable
22:30 rue_shop2 apparently it has no port A
22:30 Tom_itx huh
22:30 Tom_itx i don't remember off hand
22:31 rue_shop2 :)
22:31 rue_shop2 I'm having a hard time operating my brain
22:31 rue_shop2 maybe I should weld the wheel back on my tractor
22:32 Tom_itx portb c d
22:33 Tom_itx don't see no a
22:34 rue_house I wonder if I used it or if its part of my template
22:39 rue_house spoiler alert
22:39 rue_house http://ruemohr.org/~ircjunk/robots/arm8/p1060649.jpg
22:39 rue_house if anyone is into details or knowing how I got there,
22:39 rue_house http://ruemohr.org/~ircjunk/robots/arm8/
22:39 rue_house work back from the end
22:40 rue_house what do you think of it Tom_itx ?
22:40 rue_house I think I'm getting close to what I'm aiming for
22:41 Tom_itx which pic?
22:41 rue_house ^^
22:41 rue_house --649
22:41 Tom_itx getting better
22:42 rue_house its only the 3rd, and parts of it are just straightforward do-it
22:42 rue_house I made a bunch of grippers, cause, for that type of robot, there isn't much to change
22:43 rue_house huh, it occurs to me that the spring is better on the bottom where thre isn't as much tension
22:56 Jak_o_Shadows rue_house: is there a photo of the way you join belts?
22:56 rue_house several
22:57 Jak_o_Shadows well, I will look through them all later
22:57 rue_house http://ruemohr.org/~ircjunk/robots/arm8/p1060620.jpg
22:57 rue_house http://ruemohr.org/~ircjunk/robots/arm8/p1060621.jpg
22:57 rue_house http://ruemohr.org/~ircjunk/robots/arm8/p1060622.jpg
22:58 rue_house thats 3 wraps, with the ends twisted and folded over
22:58 rue_house http://ruemohr.org/~ircjunk/robots/arm8/p1060623.jpg
22:58 rue_house 3 peices
22:58 rue_house only about 5cm of the belt is actaully used, I could replace the middle with cables if I wanted
23:01 Jak_o_Shadows neat
23:03 Jak_o_Shadows feet!
23:03 rue_house feet?
23:03 rue_house arm
23:03 rue_house silly
23:04 rue_house do you think I should make an index page that slideshows thru all the images?
23:04 Jak_o_Shadows just thumbnails I think
23:05 rue_house no, cause then a) you have to load 23M of images every time you load the page, or b) I have to take up 8M for a thumbnail size of every image
23:06 Jak_o_Shadows B?
23:06 Jak_o_Shadows Or do it in sections
23:06 rue_house its donated space, i'm trying to be resource friendly
23:06 Jak_o_Shadows ah
23:08 Jak_o_Shadows How do you figure out the motion of the more complicated parallel linkage arms? Just mock it up?
23:11 rue_house ?
23:11 rue_house how do you mean?
23:11 Jak_o_Shadows Um, the elbow joint is actuated by that linkage bar. That obviously has more restrictions than controlling the joint at it's axis. How do you figure out that geometry?
23:11 rue_house that one is just a straighforward 1:1 linkage
23:12 rue_house yea, its via the link bar
23:12 rue_house at the base, one motor moves the lower arm segment thats directly attached to the gear
23:12 rue_house the other gear is attached to the shaft
23:13 rue_house so is the counterweight bar
23:13 rue_house and via the linkbar to the top arm segment
23:13 Jak_o_Shadows So the lower arm segment remains parallel to the upper arm segment
23:13 rue_house no, the upper arm segment is always parallel to the counterweight bar
23:14 rue_house http://www.youtube.com/watch?v=qZF9WJ1Ueew
23:15 Jak_o_Shadows the counterweight bar is the c-channel bit?
23:15 rue_house no, its at the bottom
23:16 rue_house *that* robot in the video has no counterweight on it because it was already weighted too far back
23:16 rue_house this robot only took two 3/8" nuts to balance it
23:17 Jak_o_Shadows I am calling the upper arm segment the bits the belts are running parallel to.
23:17 Jak_o_Shadows is that right?
23:17 rue_house yup
23:17 rue_house http://www.youtube.com/watch?v=sjMhJxS96Lk
23:17 rue_house different video
23:18 rue_house the thing at the back of the upper arm with the washers is a wrist counterweight
23:19 Jak_o_Shadows Yeah, because it is connected to the belt
23:20 Jak_o_Shadows Ok. The coutnerweight bar is the rectangular hollow aluminum bit?
23:21 rue_house yes
23:21 rue_house its not hollow tho
23:21 Jak_o_Shadows aha.
23:21 Jak_o_Shadows I think I was just calling it the wrong thing.
23:21 Jak_o_Shadows Also, have you thought about making the gripper slide back and forth?
23:23 rue_house you mean individual finger position control?
23:23 Jak_o_Shadows no. Um, I mean an extendable/retractable upper arm section
23:24 Jak_o_Shadows so an extendable forearm
23:25 rue_house ah
23:25 rue_house na
23:25 rue_house but I been thinking of making a cylindrical robot
23:25 rue_house which is basically just that
23:26 Jak_o_Shadows for the wrist rotation, would it have been nicer to have the joint anchored at both ends?
23:26 Jak_o_Shadows ie. http://ruemohr.org/~ircjunk/robots/arm8/p1060631.jpg
23:27 rue_house they both have twist support
23:28 rue_house one side uses a thick peice of lexan, the other side uses two peices to hold the shaft
23:28 rue_house http://ruemohr.org/~ircjunk/robots/arm8/p1060608.jpg
23:28 rue_house http://ruemohr.org/~ircjunk/robots/arm8/p1060599.jpg
23:29 rue_house there is the engineering drawing
23:29 rue_house :)
23:30 Jak_o_Shadows Um. I am talking about anchoring the twist where the nut is, more or less
23:31 rue_shop2 there are two
23:32 rue_shop2 the one on the wrist uses a long pipe to hold it steady, the other has two peice of sheet metal that hold it straight
23:32 rue_shop2 (but I hit almost everything there crookid with the drill)
23:33 rue_shop2 most of the crookidness is me not drilling or cuting things straight
23:33 Jak_o_Shadows https://dl.dropboxusercontent.com/u/104809629/capture2.PNG
23:33 rue_shop2 tahts handled by the long pipe at the bottom
23:33 rue_shop2 see those threads? they dont move
23:34 rue_shop2 the two lower nuts lock them to the two laminated peices of sheet metal
23:34 Jak_o_Shadows ohh, the thread doesn't move
23:34 Jak_o_Shadows that makes it clearer
23:35 rue_shop2 :)
23:35 rue_shop2 http://ruemohr.org/~ircjunk/robots/arm8/p1060590.jpg
23:35 rue_shop2 exploded view
23:35 Jak_o_Shadows ah
23:36 rue_shop2 http://ruemohr.org/~ircjunk/robots/arm8/p1060591.jpg
23:36 rue_shop2 the notch is used to retain grease :)
23:36 rue_shop2 the wrist plate was made of one of those bolts
23:37 rue_shop2 I had to step the stupid shaft, mix of 6mm and 5mm parts
23:39 Jak_o_Shadows I am thinking that after the 3D printer, I should get a jigsaw, and a drillpress
23:39 rue_shop2 drillpress prolly made one of the biggest differences to me
23:40 Jak_o_Shadows Yeah. Looking forward to it
23:40 rue_shop2 its nice to have a hand drill, but being abel to drill a hole parpendicular can be pretty important sometimes
23:40 rue_shop2 and you can do some lathe stuff with it
23:40 rue_shop2 put stuff in the chuck to file it down
23:41 rue_shop2 or put a drill in a vise and drill a hole down the middle of a piece of stuff
23:41 rue_shop2 and mediocre milling :)
23:41 rue_shop2 tho you ahve to be carefull, the chucks are held on with a taper friction joint, too much side force and they fall off :0
23:42 Jak_o_Shadows Yeah. I'm thinking a benchtop one would be good enough for me.
23:43 rue_shop2 mine is a 10"
23:43 rue_shop2 rarely is it too small
23:56 rue_shop2 hmm who was showing the design for the dual layer board this morning for controllign his servos