#robotics Logs
Dec 02 2015
#robotics Calendar
03:56 LiohAu but I need to rotate the kinect/camera around its center. Except if the pole is crossing the center of the kinect/camera, it's not going to act as expected
03:57 LiohAu So I really need 2 pulleys around the pole, and 1 pulley at the center of the kinect and 1 at the center of the camera, and 2 belt to drive that.
04:00 deshipu LiohAu: or have a box for the kinect, and have the pole stick from the top and bottom of it
04:01 LiohAu Yes, but that configuration is not possible, I need the rod to be like 10cm behind the kinect/camera
04:01 deshipu why not possible?
04:01 LiohAu But I agree that solution would work
04:01 deshipu --[_]--
04:01 deshipu like this
04:01 deshipu only vertical
04:02 LiohAu hm, well I have a kinect in front of the torso, and a camera in the head of the robot, a pole would be visible from outside of the robot body :d
04:03 LiohAu except if it's behind, so it becomes like a neck
04:03 LiohAu (or spinal column)
04:07 deshipu any pulleys or gears or other such mechanical things will introduce vibrations and inaccuracies
04:34 LiohAu deshipu: and i won't be able to know where my kinect image comes from :(
04:35 deshipu it comes from the kinect, no?
04:37 LiohAu deshipu: I meant that if I don't know the exact position of my kinect in my robot (because of gear/pulley inaccuracies), I can't use the image coming from the kinect
04:39 LiohAu i'm going to use AX-12 or AX-18 servos to make this rotation, so maybe precision will be good enogu
04:39 LiohAu enough*
04:41 deshipu what I meant is that it's hard to beat the precission of a fixed connection
05:37 maiden i found something awesome recently: http://www.frontiersin.org/files/Articles/130437/frobt-02-00014-HTML/image_m/frobt-02-00014-g002.jpg
05:37 maiden from this article: http://journal.frontiersin.org/article/10.3389/frobt.2015.00014/full
05:38 deshipu hmm, the knees look pretty bad
05:38 maiden http://www.frontiersin.org/files/Articles/130437/frobt-02-00014-HTML/image_m/frobt-02-00014-g001.jpg
05:38 deshipu lots of angular force on those joints
05:39 maiden i agree,
05:40 maiden i would have added an metal plate on the inside to avoid the torque, i wonder why its excluded. there is plenty of space and seams like an obvious solution to an obvious problem..
05:41 deshipu there are probably two bearings in that tube
05:41 deshipu and they give enough support
05:41 maiden i do not think its something that have been overlooked, if you consider the work put in on the robot.
05:42 maiden but i am so going to use the measurements for my robot ;)
05:42 deshipu the hip joints look complex
05:43 maiden i also run in to this: http://www.cs.cmu.edu/~cga/walking/grad.html
05:43 maiden so now i have a lot of new material to study and evaluate in my simulator.
05:49 deshipu why study if you are going to die anyways?
06:03 maiden deshipu?
08:45 LiohAu deshipu: who's gonna die?
08:46 deshipu all of us
08:46 deshipu eventually
09:06 rue_mohr everyone gonna die
09:20 LiohAu new problems for you guys
09:20 LiohAu my robot needs to reduce its height
09:20 LiohAu I have the linear actuator, the electronics ...
09:20 LiohAu but one more time, I'm stuck with mechanical part
09:22 LiohAu I think I need a kind of telescopic linear guide
09:25 LiohAu basically, I need to squeeze the red part : https://sketch.io/render/sketch565f078b5c672.png
09:25 LiohAu (I know i'm an artist :D)
09:30 LiohAu if I wasn't trying to make a robot that can reduce its height, I would use alloy/carbon fiber or any other solid material for the green tube here : https://sketch.io/render/sketch565f08a724678.png
09:31 LiohAu trying to start a robotics topic and nobody is interested, really weird channel :P
09:34 LiohAu SpeedEvil: maybe you will have an idea as your also on #mechanics?
09:39 LiohAu i'm really sad that nobody even laughed about my sketch :(
09:45 SpeedEvil I am exhausted at the moment by trying to parse shitty laws.
09:45 SpeedEvil Are you familiar with a scissor lift?
09:48 LiohAu SpeedEvil: yes
09:48 LiohAu it was our first idea
09:49 SpeedEvil why not
09:49 LiohAu and then we thought about a lead screw (and a partner suggested something like this : http://i88.servimg.com/u/f88/14/28/73/35/49010.jpg
09:50 SpeedEvil It is unclear
09:50 SpeedEvil what's this robot to do - what sort of loads?
09:51 LiohAu well the torso will be around 30kgs
09:51 SpeedEvil what sort of robot is it
09:52 LiohAu a kind of humanoid but with wheels instead of legs
09:52 SpeedEvil drawer slides are quite within that range
09:52 LiohAu i'm afraid about stability :(
09:53 LiohAu won't it looks like the jenga game ?
09:54 SpeedEvil What sort of duty is this.
09:54 LiohAu ?
09:54 SpeedEvil Is it a demo robot, or is expected to go 8 hours a day for 5 years carrying loads at varying heights
09:54 LiohAu no it's not a demo robot
09:55 SpeedEvil What the mechanism you posted above does is unclear
09:55 SpeedEvil what
09:55 LiohAu it corresponds to your 2nd hypothesis
09:55 LiohAu the mechanism in the drawing?
09:55 SpeedEvil the picture
09:56 LiohAu well I could share a more detailed picture, but I would have to kill everybody on the channel after that :P
09:56 LiohAu or do you mind if I PM you ?
09:56 SpeedEvil Also, the green tubes in the drawing have the problem that there is no cross-bracing
09:56 SpeedEvil and they will wobble.
09:57 SpeedEvil No, I'm not willing to do private discussions, as those benefit one person, and nobody else can butt in if they see something wrong.
09:57 LiohAu cross-bracing means that : http://thumbs.dreamstime.com/x/grue-et-ciel-1096036.jpg ?
09:58 LiohAu (nvm google image confirmed)
09:58 LiohAu pm: Ok, no problem, I just cannot share more than this sketch publicly
10:02 robotustra hi
10:07 LiohAu SpeedEvil: did I miss something with the split?
10:07 SpeedEvil As a general point.
10:07 SpeedEvil no
10:08 LiohAu SpeedEvil: ok. well you can look at this https://unsee.cc/puzadise/
10:08 SpeedEvil As a general point, asking a lift to do more than one thing at once adds cost, weight and expense
10:08 LiohAu (if you wish)
10:09 SpeedEvil For example, you can do a simple lift using a spring, a string, and a motor to winch the string down.
10:09 LiohAu when you say "more than one thing", you mean stability is the first thing, and lifting is the 2nd one?
10:09 robotustra image was deleted
10:09 LiohAu robotustra: that's the point !
10:09 SpeedEvil Adding stability and security in one or more axes and reliability adds lots and lots of cost
10:10 LiohAu So your advice would be to drop the lifting feature ? :)
10:11 SpeedEvil No, it's that expecting it to come prepackaged in one unit is going to cost a lot more.
10:11 LiohAu oh ok. But I could make it myself right?
10:11 Snert Also, decide on what you want and build it. You won't be happy with what you didn't want.
10:12 SpeedEvil http://www.ebay.co.uk/itm/4-6-8-10-12-14-16-18-inch-330lbs-Linear-Actuator-electric-Motor-for-auto-lift-/351525145692?var=&hash=item51d8880c5c:m:muKOZVDpF_37titzxv-tj0w
10:12 SpeedEvil yes
10:12 LiohAu Actuation is the easiest part of the problem
10:12 SpeedEvil Google to find something already used for similar apps that works, and then find diagrams or patents on how it works to recreate
10:14 LiohAu With all the things you told me about the lead screw for the shoulder, I have a lot of ideas for the actuators
10:14 LiohAu my main issue was the mechanical part
10:14 LiohAu but what you said about the cross-brace, is already a good tip
10:16 robotustra what are you talking about?
10:16 LiohAu me?
10:16 robotustra yeah
10:16 LiohAu in which sentence?
10:17 robotustra I mean what is your project?
10:17 robotustra what do you design
10:17 LiohAu well it's a robot, but one part can lift
10:17 LiohAu (or compress)
10:18 robotustra show the picture
10:18 LiohAu think about a turtlebot that could change its height
10:18 LiohAu I can share you that if you wish : https://sketch.io/render/sketch565f078b5c672.png
10:19 LiohAu the part surrounded by red lines compress
10:19 robotustra ок
10:20 robotustra I do something similar
10:20 LiohAu No you don't
10:20 robotustra really?
10:20 LiohAu You showed your robot last time
10:20 robotustra ah ok
10:20 robotustra robot on wheels
10:20 robotustra yeah
10:20 LiohAu your thing does not compress
10:20 robotustra what do you mean compress?
10:21 LiohAu I mean your robot does not touch the floor by a linear motion
10:21 robotustra shrink in size?
10:21 LiohAu yes, maybe shrink is the appropriate word, sorry
10:21 robotustra I want it to pick up things from the floor
10:22 LiohAu iirc your picture, your robot use a kind of pivot
10:22 robotustra so it will bend and pick up
10:22 LiohAu yes "bend" was the word I was looking for
10:22 LiohAu your robot "bend", mine "shrink"
10:22 robotustra ok
10:22 robotustra with curragated hose?
10:22 robotustra 1 sec
10:23 LiohAu I don't know what "curragated hose" is
10:23 LiohAu sorry :d
10:23 LiohAu oh corragated hose, no
10:24 LiohAu maybe if I find a large enough one
10:25 LiohAu always when I have an interesting talking that I need to go :(
10:27 robotustra I saw 1 robot that can change the height
10:27 robotustra but it was usual stepper motor + threaded rod
10:27 LiohAu http://electronicdesign.com/site-files/electronicdesign.com/files/uploads/2015/06/fig%203%20FetchRobotics-Fetch%20format%20f.jpg
10:28 LiohAu given the arm+head+torso+load may be around 20kg
10:28 LiohAu how do they keep stability
10:28 LiohAu do you really think it's a scissor lift in this case?
10:29 robotustra https://www.youtube.com/watch?v=m_ZEolNi9c0
10:29 robotustra heavy base I think
10:30 robotustra Hope today I'll finish the box for the base of my robot
10:30 LiohAu brb
10:30 robotustra bye
12:07 ferdna does anyone owns a smoothieboard?
12:10 deshipu ask your real question
12:11 deshipu the chance that someone on this channel owns the same gadget as you *and* is online at this moment *and* wants to answe is small, but chance that someone will know the solution to your problem is much better
12:22 ferdna i would like to know the differences between version 1,.0a and b
12:22 ferdna deshipu, ^
12:22 deshipu ah, no idea, sorry
12:23 ferdna also where could i purchase it? the fully assembled one
12:53 robotustra ferdna: do you know what is google?
12:58 anonnumberanon "You do need to weigh your options though. If you have a very complex amount of firmware, adding the overhead on both you as a programmer and the cpu usage may not be worth it and you would be better off to just add a little bit of hardware. Now on the other hand, if you are trying to get costs and size down, you will want to remove as much hardware as possible and do it all in firmware if you can."
12:58 anonnumberanon On debouncing.
13:03 anonnumberanon ferdna, http://shop.uberclock.com/collections/smoothie
13:06 ferdna wtf is google?
13:07 ferdna anonnumberanon, hmmm yes that is the link that i was on... if you try to add... version number 1.0b and/or other that is not -xM
13:07 ferdna it will not let you add to cart
13:11 anonnumberanon only the 5x is available from that store everything else is sold out
13:11 judahz so has anyone sucessfully demonstrated any projects with uberclock that are worth looking at
13:11 judahz that are also open source, guess i could look myself
13:14 anonnumberanon If you
13:14 judahz http://smoothieware.org/gallery
13:14 anonnumberanon re buidling a printer from scratch why not do it from basic components.
13:15 judahz i dont see the appeal for people that really need to make things
13:15 anonnumberanon Time you'll spend will be five times more (and you won't really actually still know how it works) than just working and getting money and buying a ready built one.
13:15 judahz seems like a-lot of troubleshooting / time sink
13:16 judahz ^
13:16 judahz "whats gcode" lol
13:17 anonnumberanon I wouldn't spend more than $30-40 on the controlling board to be honest, assuming doing it from scratch everything.
13:17 anonnumberanon Exercise is prolly reserved to those who have already played with 32 bit micros.
13:19 judahz i guess its a cool idea, but its not what i consider an open source solution
13:19 anonnumberanon Why is that thing not open source?
14:06 ferdna judahz, ^
16:29 anonnumberanon flashing chip with ICSP so much faster
16:36 LiohAu SpeedEvil: currently reading stuff about structures (truss especially) that solve an issue I had about stability of the upper parts for my robots
16:36 LiohAu but I'm wondering wether a structure like that can be telescopic oO
16:37 SpeedEvil it's more comp[lex, in some cases
16:37 SpeedEvil https://www.google.co.uk/search?q=telescoping+crane&client=firefox-a&rls=org.mozilla:en-US:official&channel=fflb&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiZouKamb7JAhUCXhoKHVh3BlIQ_AUICCgC&biw=1067&bih=530
16:38 SpeedEvil http://www.giveng.com/Images/Stainless_Jib.jpg for example is a simple example
16:39 LiohAu didn't think about crane, good keyword thanks
18:23 anonnumberanon hey rue_mohr what does jitter do to servos, lets say 10us jitter vs 100 us jitter?
18:27 Tom_itx makes them shake
18:27 Tom_itx not finding center freq
18:29 anonnumberanon Tom_itx, I get 8us jitter right now, adding 6 more servos so I'm thinking I'll get about 20 us jitter afterwards, that'll be 12 servos total connected to the micro without any additional hardware.
18:30 anonnumberanon I could do 17 servos but 5 pins are taken by the wireless chip communication.
18:30 anonnumberanon Not gonna complain, it's fast as hell.
18:34 jhylands anonnumberanon, what are you building?
18:35 anonnumberanon jhylands, small biped robot
18:35 jhylands Cool - I tend to use Bioloid servos for that sort of thing
18:36 anonnumberanon Bioloid servos would be really really nice. :)
18:37 jhylands I've got 13 on my current robot - just AX-12's, but they're still nice
18:37 anonnumberanon What kinda robot is it?
18:37 jhylands its a quad walker
18:37 anonnumberanon cool, got any pics?
18:37 jhylands http://blog.huv.com/2015/11/roz-walks-again.html
18:38 anonnumberanon awesome, got vid?
18:38 jhylands there's one on that page
18:38 anonnumberanon found it heh
18:39 jhylands https://www.youtube.com/watch?v=iL9w-wTjzeM
18:39 jhylands I've been working more more on the obstacle detection and avoidance since I put that video up
18:40 anonnumberanon cool, it's pretty powerful and smart
18:40 anonnumberanon what batteries do you have?
18:40 jhylands http://blog.huv.com/2015/12/roz-obstacle-scanning.html
18:40 jhylands Right now its just a 3-cell 1000 mAh Lipo
18:40 anonnumberanon how long can it run as fast as in the video?
18:40 jhylands I really want a 2000 mAh, but its hard to find one to fit the space I have
18:41 anonnumberanon can you do 10 min?
18:41 jhylands probably 10 minutes
18:41 jhylands I'm about to test that tonight, actually
18:41 jhylands but one of the vinyl feet came off, so I had to glue it back on
18:42 jhylands one really nice thing with the AX-12's - you can monitor the battery using the servos
18:42 jhylands so I shut it down when the battery dips below 10 volts
18:42 anonnumberanon I'm looking at a 2 cell 1000mah for mine. Since servos are at 5V.
18:43 jhylands yeah, AX-12's run at 12 volts
18:43 jhylands so 3 cell is good
18:43 anonnumberanon Ah that's great that you can do that. Can you monitor the temperature of them as well?
18:43 jhylands yeah
18:43 anonnumberanon :)
18:43 jhylands I have a watchdog routine that runs every 5 seconds, checks the battery and round-robins the servos for temp
18:45 anonnumberanon what controller do you use, some gamepad?
18:45 jhylands no, its autonomous
18:45 jhylands I'm not controlling it at all
18:46 jhylands I'm running code on a MicroPython board
18:46 jhylands https://github.com/JonHylands/roz
18:47 anonnumberanon man that's a good chip
18:48 jhylands http://www.micropython.org
18:48 anonnumberanon you can put all the intelligence you want on that thing :)
18:48 anonnumberanon I know im looking at it right now heh.
18:48 jhylands its got a lot of memory and processing speed
18:48 anonnumberanon https://micropython.org/static/store/img/products/PYBv1_1-E.jpg
18:48 jhylands I'm using a custom board I designed, but its the same chip
18:50 jhylands MicroPython is really nice to work with - you just copy the source files to the chip, and hit reset
18:50 jhylands it compiles everything on the chip, and runs it
18:53 anonnumberanon no OS huh?
18:53 anonnumberanon well, OS could mean a lot of things
18:54 anonnumberanon This one of yours looked awesome too https://www.youtube.com/watch?v=BBNOs9JHqXA
18:54 anonnumberanon I'm building something like this: https://www.youtube.com/watch?v=_OxQD5-RPNw
18:54 jhylands Yeah, that was running Linux
18:55 jhylands too much of a pain
18:55 jhylands for a robot with a relatively small battery
18:56 jhylands That's why I like MicroPython so much - it is instant-on
18:57 anonnumberanon Yep, great system.
18:58 jhylands my brother wrote a remote-shell for it, so I work in PyCharm, save my code locally, copy the file to the uSD card (using the USB connection to the board)
18:58 jhylands and then reset the board
19:03 anonnumberanon Is this your career?
19:12 jhylands no, just a hobby
19:13 jhylands I just did a run, got almost exactly 10 minutes out of one battery
19:14 jhylands 607 seconds, according to the log file, but I ran it about a minute before that also
19:15 jhylands so about 11 minutes
19:15 anonnumberanon that's 1000 mah?
19:15 jhylands 1000 milli-amp hours
19:15 jhylands yeah
19:15 jhylands this is the last watchdog entry from the log:
19:15 jhylands 00607180: Watchdog: Servo ID 12 - Voltage: 9.1 volts, Temperature: 46 C
19:15 jhylands 00607185: Battery too low: 9.1 volts - shutting down
19:15 jhylands 00607212: Shutdown
19:16 anonnumberanon yeah like about 3.1V per cell
19:16 iregistered hey! i'm having trouble understanding something in the spec of an arduino shield from seeed. anyone got a sec?
19:16 jhylands well, the previous watchdog log entry said 10.7 volts
19:16 jhylands it jumps up and down
19:16 anonnumberanon iregistered, post your quesiton and links
19:17 anonnumberanon jhylands, intriguing..
19:19 iregistered anonnumberanon, http://www.seeedstudio.com/wiki/SD_Card_shield_V4.0
19:20 iregistered it says at some point that "pin 4 is used for consistency with other arduinos"
19:20 iregistered but why is it used?
19:20 jhylands CS
19:20 jhylands chip-select
19:21 jhylands they're saying lots of Arduino examples use pin 4 for the CS line for SPI
19:22 jhylands and so they are too
19:22 anonnumberanon iregistered, yeah almost all the other pins could be used
19:22 iregistered wait, so is it pin 4 on the black header or pin 4 on the spi?
19:22 anonnumberanon black header
19:22 anonnumberanon (on the arduino board)
19:22 iregistered so it's a matter of just subbing out the pin #?
19:23 anonnumberanon where it says Digital, there, at pin4 on that side http://www.seeedstudio.com/wiki/images/7/70/Sd_card_sld.jpg
19:23 iregistered got it.
19:24 jhylands I actually have two identical 1000 mAh batteries, and they would both fit in the battery compartment
19:24 iregistered so if my pin 4 is being used for something else, i can just change the number in the code?
19:24 jhylands so I might just parallel them to get 2000 mAh
19:25 jhylands are you plugging the shield directly to the arduino?
19:25 anonnumberanon iregistered, how much memory can you have on that sd card, like GigaBytes? how fast is it to get data from it, do you know?
19:25 iregistered without seeed secret sauce code, it reads up to 4 gigs
19:26 iregistered jhylands, i plan to but i'm flexible ^o^
19:26 jhylands you'll have to, because if you plug it in, the line on the shield will be on pin 4
19:26 anonnumberanon that's nice, you could make an mp3 player or something with that thing
19:26 jhylands anonnumberanon, I've used this one: https://www.sparkfun.com/products/9530
19:27 jhylands but it was for logging
19:27 jhylands I use a 16 GB card in it
19:27 jhylands but its only 115200
19:28 anonnumberanon good stuff
19:29 anonnumberanon yeah 115200 is fast enough
19:30 anonnumberanon unless you're storing video data (maybe even sound may be too heavy)
19:31 jhylands yeah, I suspect it would be - you normally want 128 KHz for good quality stereo audio
19:31 jhylands but it would be close
19:31 anonnumberanon jhylands, yeah I need to look up putting power sources in parallel as well cause I have been wondering for a long time whether or not anything can go wrong by doing so.
19:32 jhylands you need to balance charge them individually
19:32 jhylands but as long as they are the same battery, and they are both fully charged when you plug them together, you won't have any trouble
19:32 anonnumberanon well yeah, or maybe if your charger has a plug that takes 6 balance ports..
19:32 onnumberanon checks my acc
19:33 jhylands I wouldn't ever charge a lipo while its plugged with another one
19:33 jhylands I tend to use Y-connectors
19:33 anonnumberanon yep there is a 7 port header, 1 for ground
19:33 jhylands so they are easy to take apart
19:34 jhylands 7-port is for a 6-cell battery
19:34 jhylands you could probably charge both at the same time, but I would unplug the main plug while you're doing it
19:34 anonnumberanon what main plug?
19:34 anonnumberanon i think it would just work
19:35 jhylands the place you plug the robot to
19:36 anonnumberanon I haven't thought about that issue for mine
19:36 anonnumberanon charging "in robot"
19:37 jhylands pretty much all multi-cell lipos have two ports - one that has two wires, to power the load, and one that has N+1 wires, where N is the # of cells
19:38 jhylands that one is for charging
19:38 anonnumberanon uhm actually i think those are for discharging
19:38 jhylands no, they are for balance charging, but you can plug a discharge thing to them as well
19:38 anonnumberanon the fat cables for charging and the N wires for discharging whatever cell has too much
19:39 jhylands for really bit lipos that is true
19:39 jhylands but most small lipo chargers charge using the balance plug
19:39 anonnumberanon huh
19:39 jhylands you can only charge at 1C, so you don't need the big heavy connector
19:40 jhylands where they can power the load at 20-30C
19:40 jhylands depending on the battery
19:40 anonnumberanon good to know!! :)
19:40 jhylands I have an 8000 mAh lipo that charges that way, but the charger uses the balance plug to balance while its charging
19:40 jhylands since you're putting 8 amps into the battery to charge it
19:50 dingbat Hoi
19:53 jhylands evening
19:56 dingbat Never lurked here before, how active is #robotics?
19:56 Snert_ why, we're so awesome and amazing that we don't even need to apeak :)
19:56 Jak_o_Shadows yo
19:58 anonnumberanon Okay 16 us jitter with 12 servos.
19:59 Snert_ are these openservos?
20:00 anonnumberanon Right in the ballpark, but better. Nah Snert. Doesn't matter I'm measuring the output of the microcontroller, but no they are regular hobby servos, analog ones.
20:02 Snert_ I need to do my servo thing. What is the 16uS jitter factor? 12 individual servo pwm signels each with 16uS of jitter?
20:04 anonnumberanon Snert_, I'm checking the distribution of jitter right now. Also I got one last test before I start playing around with standing the robot: test running only one servo and listen for the servo jitter, then quickly switch to 12 servos and listen to the servo jitter, if there is a noticeable audible jitter or something I may know it.
20:05 Snert_ yea, with these cheep servos eyes and ears are best.
20:05 Snert_ you'll know it fastest when something is amiss.
20:07 anonnumberanon Yeah, and you know what, I really hope the ranges for the pwm stay consistent, I know they are a bit different for each servo but if each servo's pwm range is consistent, at least you can hardwire those ranges (to map them into useful range)and stuff).
20:09 akem c3p0 is horny
20:09 Snert_ CmeP2 ?
20:10 Snert_ that's what my robot name is gonnabe :)
20:10 anonnumberanon Snert_, post your roboto :)
20:11 Snert_ Wish I had one. I'm working on the closed loop control system.
20:11 Snert_ I have almost all the motors and parts for my test system.
20:12 Snert_ quadrature decoder chips arrived testerday.
20:13 Snert_ so I'll hitch it all together in the next month and see if I can achieve closed loop control of 3 steppers and 3 encoders.
20:14 dingbat So, I need the channel's advice: Planning a small autonomous robot, all it has to do is drive a prescribed course. Planning on using GPS and some rangefinders on a small 4 wheel car. I need an MCU or SBC to run it. Any suggestions are appreciated
20:15 jhylands dingbat, how big is this robot?
20:16 dingbat Well, I'm not entirely sure yet. Might be building two. But let's say about 12"x6". Pretty big
20:16 jhylands 12 inches x 6 inches?
20:17 dingbat Yep. Maybe larger
20:17 jhylands okay, so not a lot of room for big batteries
20:17 jhylands if I was doing a vehicle like that I would use MicroPython, but I really like it
20:18 jhylands it really depends on what language you want to use
20:18 anonnumberanon yeah dingbat what do you code in if any?
20:18 dingbat jhylands: well, I'm open to anything that isn't (in my opinion) silly.
20:18 jhylands that doesn't help much
20:19 jhylands have you programmed any embedded boards before?
20:20 rue_mohr Snert, why do you need quadrature decoder chips!?
20:20 dingbat Yes, I have experience with a whole slew of embedded platforms (Arduino/AVR, STM8/32, ESP8266, Freescale Kinetis, various FPGA platforms). Just not robotics platforms, hence the request for suggestions
20:20 jhylands Do you know/like Python?
20:20 jhylands or is that silly?
20:20 Hyratel dingbat, I missed the synppsis, what're you trying to do/learn?
20:21 dingbat I'm comfortable with C, C++, Lua, etc. But this is going to be a group project, so group members will have to learn the language of choice
20:21 ace4016 my opinion on the matter is to use whatever is necessary to meet your goal
20:21 dingbat Hyratel: just looking for a microcontroller or single-board computer for a small autonomous driving robot
20:21 jhylands You could do it with an Arduino, but personally I can't stand C++, so I prefer MicroPython
20:21 Hyratel rpi with an rtos
20:22 dingbat jhylands: I'm somewhat comfortable Python, but not in the context of embedded. Could be an option though, what's your favourite platform for MicroPython
20:22 jhylands unless you want to do vision processing, rpi is overkill
20:22 rue_mohr surely you can find soemthing with more kick than a rpo
20:22 rue_mohr rpi
20:22 dingbat Hyratel: do you have a favourite RTOS for the rpi?
20:22 rue_mohr terraflops man! were flashing leds here!
20:22 jhylands dingbat, https://github.com/JonHylands/roz
20:22 rue_mohr put the os on a vm!
20:22 rue_mohr wait, how can we add more overhead!
20:23 rue_mohr make a python engine written in java!
20:23 Hyratel no - thats an academic suggestion, not a practical one
20:23 dingbat rue_mohr: haha if I had total control, I'd put a Artix board with two or three softcores on there. For that blistering fast parallelism...
20:23 rue_mohr dude, just go with a dual 8 core pentium
20:23 jhylands this robot is 6" x 12"
20:23 rue_mohr still
20:23 jhylands the one dingbat is describing
20:23 rue_mohr use a microatx baord
20:24 rue_mohr of a pile of them, cluster computing!
20:24 rue_mohr FIND a way to spend NO LESS than $50000!
20:25 jhylands been there, done that - http://blog.huv.com/2010/03/brainbot-outdoor-navigation.html
20:25 rue_mohr make the robot of a 36" cube of aluminum, cnc'd down to a 1/32" sheet
20:25 jhylands well, it was more like $12K
20:25 dingbat Um. Y'all are ridiculous.
20:25 rue_mohr yea, beat that so bad its budget is left int eh dust!
20:26 jhylands like I said, MicroPython - great language, very powerful MCU, lots of good hardware interfacing
20:26 dingbat Let's say, less than $100.
20:27 jhylands http://www.adafruit.com/products/2390
20:27 jhylands or if you're on the other side of the pond: https://micropython.org/store/#/store
20:28 dingbat Ok cool, that looks cute
20:28 rue_mohr an arm is NOT expensive enough!
20:28 rue_mohr you need something made from atleast 4 high grade FPGAs
20:28 orlock Hmm
20:28 rue_mohr the ones that cost atleast $10000 ea
20:28 jhylands I built my own board to run it, but its an awesome system all in all
20:29 orlock Inneresting changes at work
20:29 rue_mohr and then, before the project is finished, you need to throw it away and upgrade it
20:29 dingbat rue_mohr: an array of Virtex Ultrascale devices...
20:29 orlock the new name of Fluke/Tek/etc will be announced today apparently
20:29 dingbat orlock: eh?
20:30 orlock dingbat: The company that owns them is splitting into two
20:30 rue_mohr only then can you emulate a pc so you can run a vm on it that can run an os that can run the evironment that can run the interperter that can execute the code to flash the led!
20:30 orlock dingbat: they are announcing the new company name today
20:31 ratel smacks rue_mohr to make him stop skipp
20:31 rue_mohr screw using a 555, we can spend $400000 easy on this!
20:32 dingbat orlock: when?
20:34 orlock http://www.forbes.com/sites/antoinegara/2015/05/13/danaher-activists-platform-stock-steven-rales-mitchell-rales-ackman/
20:35 Snert rue_mohr: because I want to offload position detection and tracking from the arduino.
20:36 dingbat Huh. So will Fluke/Tek keep their names, or will everything be rebranded
20:36 rue_mohr if you were to use an avr instead of an arduino you would prolly be ok
20:36 orlock dingbat: Same names, its only the holding company
20:36 rue_mohr its usually pretty easy to track up to 4 grey encoders
20:37 orlock rue_mohr: Have you played with an ESP yet?
20:37 dingbat orlock: ah.
20:38 ace4016 gah, cheapest IR temp sensor i can find is $845
20:38 dingbat What?! There has got to be some much cheaper than that. What kinda range you need?
20:39 rue_mohr hahaha
20:39 rue_mohr $36
20:39 ace4016 i need to measure up to 1800 C
20:39 dingbat Oh christ, nevermind then
20:39 ace4016 lol
20:40 rue_mohr why not use a thermocouple?
20:40 rue_mohr hah$10 they came down
20:40 dingbat Or, why are you looking at liquid titanium. Or whatever it is?
20:41 rue_mohr brass?
20:41 ace4016 rue_mohr, looked at how much a thermocouple that can take 1800 C cost?
20:41 rue_mohr http://www.aliexpress.com/item/HoldPeak-HP-1300-Non-contact-16-1-Digital-Infrared-IR-Thermometer-Laser-Temperature-Gun-Sensor-Meter/32281316705.html
20:42 rue_mohr so close
20:42 rue_mohr it just goes it a protective tube
20:42 rue_mohr K class
20:42 ace4016 i need B class
20:42 ace4016 those are usually platinum alloy stuff (apparently platinum has a REALLY high melting point)
20:43 ace4016 fixed-mount would be nicer than hand held as well...
20:44 rue_mohr you casting?
20:44 ace4016 as it may take 10 hours for the parts to get up to temp without being stressed too much
20:44 ace4016 firing ceramics
20:44 ace4016 i could just guesstimate and not worry about actual temps
20:44 rue_mohr whats the limit on type K?
20:45 ace4016 but that seems like a bad idea; unless it's the norm
20:45 dingbat jhylands: Can MicroPython run on the STM32F407 Discovery boards?
20:45 rue_mohr I'm sure I'v dipped my K inot molten aluminum
20:45 ace4016 type K is up to 1260 C
20:45 jhylands dingbat, yeas
20:46 ace4016 melting point of 1400 C
20:46 ace4016 400 C lower than it will be exposed to
20:46 jhylands dingbat, https://github.com/micropython/micropython/wiki/Board-STM32F407-Discovery
20:46 dingbat jhylands: awesome, thanks for the link. That's a very affordable board
20:47 ace4016 Tybe B will work, but it gets pricey
20:47 jhylands dingbat, I've got it running on one of these also: http://www.espruino.com/Pico
20:47 rue_mohr well, looks like even on the cheap,a B thermocouple runs $228
20:47 jhylands although that board isn't as powerful
20:47 ace4016 rue_mohr, link?
20:48 ace4016 i think i found that one before
20:48 dingbat jhylands: well, those are adorable :) Haven't seen them before. Don't think they've got enough GPIO for our application though
20:48 jhylands https://github.com/micropython/micropython/wiki/Boards-Summary
20:48 rue_mohr its an average of a lot of listings
20:49 rue_mohr says only good to 1700c
20:49 ace4016 hrmf
20:49 ace4016 i might be able to build my own IR thermometer
20:49 rue_mohr maybe you should just use a cone like everyone else
20:50 ace4016 cones don't go that high iirc
20:50 ace4016 also takes too much effort to keep observing cones
20:50 rue_mohr if they dont, your pottery is gonna melt?
20:50 jhylands 7.4 minutes of Roz walking: https://youtu.be/1q4nsocmLWU
20:50 ace4016 i'm not making pottery
20:51 rue_mohr and its a youtube link!
20:51 jhylands not just a random youtube link, one of my videos
20:51 rue_mohr hard to get the kinematics right with the joints in those extremes
20:52 jhylands This is all autonomous, btw
20:52 rue_mohr pretty good tho, I cant see any major slipping
20:53 Tom_itx hey jon, ltns
20:53 rue_mohr always 2 legs flying?
20:53 jhylands yeah, its an amble gait
20:53 jhylands two up, two down
20:55 ace4016 as i've learned recently, high-temp == expensive
20:55 rue_mohr *sigh* I should get mine going
20:55 jhylands I wanted to see it get stuck enough that it would use my new scan routine
20:55 jhylands but it didn't
20:55 rue_mohr ace4016, what melts at 1800?
20:55 rue_mohr aside from the bricks in the kiln
20:55 ace4016 alumina
20:55 rue_mohr hah, your gonna do your own electolysis!
20:55 ace4016 aka aluminium oxide
20:56 ace4016 making engine parts and other high temp parts
20:56 rue_mohr out of aluminum?
20:56 rue_mohr and your refining your own aluminum?
20:56 ace4016 alumina
20:56 ace4016 not aluminium
20:57 ace4016 i should just say aluminum oxide so you don't get confused
20:57 rue_mohr I'd just assume your doing electrolysis to get it refined back inot aluminum
20:58 orlock aluminium
20:58 Tom_itx jhylands, looking at your blog on your sherline... did you decide on a cad cam?
20:58 jhylands I'm using CamBam
20:58 jhylands for CAM
20:58 ace4016 ah, no. i want/need it in the ceramic form
20:58 rue_mohr well, if your gonna do that you might as well magnetically suspend it and use induction heat
20:58 Tom_itx you know you can get fusion 360 free?
20:58 ace4016 i need the high temp properties
20:58 jhylands I used to use Rhino for Cad, but lately I've been using OnShape which is awesome
20:59 rue_mohr hmm I suppose its not conductive, hmmm
20:59 Tom_itx small comanies / personal use it's free
20:59 Tom_itx companies*
20:59 ace4016 i didn't think alumina was that magnetically susceptable. also, i don't have an issue containing it; i have an issue measuring its temp
20:59 jhylands OnShape is like an online version of Solidworks
20:59 Tom_itx i like sw
21:00 Tom_itx don't use it for cad cam though
21:00 jhylands I mostly do 3D printing, and OnShape is awesome for that
21:00 rue_mohr everything is, you just need a strong enough magnet
21:00 ace4016 lol
21:00 Tom_itx sw will 3d print direct
21:00 orlock jhylands: i never got the hang of anything but openscad
21:00 orlock probably says something about my brain
21:00 jhylands OnShape is a parametric modeler
21:00 rue_mohr not being in a net gravitational field would help too
21:01 orlock work bought some more printers
21:01 rue_mohr ... being in a net 0 gravitational field...
21:01 rue_mohr hmm
21:01 orlock 5 in total now
21:01 rue_mohr orlock, dont you go grade headstones?
21:01 rue_mohr grave
21:01 ace4016 i've already got a flame detector, nozzles+adapters and a fuel pump and motor to run the pump
21:01 orlock hah hah hah
21:01 orlock :P
21:01 ace4016 need to make the burner housing
21:03 rue_mohr I used to love using the cutting torch to form alumina, the crystals grow in the most awesome way
21:03 Tom_itx Onshape is cloud based?
21:03 jhylands yeah
21:03 Tom_itx not wild about that
21:05 anonnumberanon dingbat> Let's say, less than $100.
21:05 anonnumberanon lol
21:05 anonnumberanon just for the brain?
21:06 dingbat anonnumberanon: yeah. I mean, ideally we'd be sub $25. But I don't think sub $100 is unreasonable
21:25 anonnumberanon So I've tested both 1 pwm and 12 pwms and in both case, the jitter did not affect nor the position nor the response of the servo. I am thinking those servos may have a "dead band". Not sure if the dead band is consistent, but that's good news though, gives a good benchmark to compare with using more hardware to drive more servos.
21:29 anonnumberanon dingbat, everything is really hard to do it's good to write down goals that you want to achieve no matter what, that way you don't try to go overboard with it and not finish.
21:30 anonnumberanon dingbat, ultimate goals should be "do this in this situation and that situation"
21:30 anonnumberanon "spending this"
21:30 anonnumberanon "learning this"
21:30 jhylands and don't expect to always get reasonable sensor data, especially from the GPS
21:31 dingbat anonnumberanon: yeah, fair point. I'm still in far planning stages, and I'm not paying for it out of pocket.
21:31 anonnumberanon dingbat, so, what's the budget? (the more money the better)
21:33 dingbat jhylands: yeah, GPS is going to be difficult. Both update rate and reliable data with nearby obstructions. I'm actually thinking about running multiple GPS units to see if I can get better data
21:34 anonnumberanon dingbat, if GPS then outside, if outside then fat mean tires
21:34 dingbat Haha, should be just pavement. But yeah, we've got some sort of RC platform with nice tires
21:35 anonnumberanon great start, so low budget
21:35 anonnumberanon jhylands, haha awesome (your video post)
21:35 jhylands thanks
22:22 anonnumberanon jhylands, someone juggested you put a Neato Lidar on top of it.
22:24 ace4016 huh...partially expected him to be in here