#robotics Logs
Jul 03 2017
#robotics Calendar
12:24 AM rue_shop3: drat, my gearlib version dosn't have a rack
12:27 AM rue_shop3: and I need to start supper
01:18 AM rue_house: thats 13 circuyit boards so far, the box is starting to show it
01:19 AM rue_house: I dont get why the model M is the only keyboard my fingets seem to line up on
02:57 AM rue_house: sweet, lots of cars cost more than the amount left on my mortguage
02:59 AM hypodyne: Glad I paid my house off, debt sucks.
03:30 AM rue_house: jester?
03:30 AM rue_house: the_jester?
03:30 AM rue_house: hmmm
03:39 AM rue_house: hah, they have the #2 screws jester loves to much too!
04:15 AM rue_shop3: no jester?
04:15 AM rue_shop3: :/ maybe he is actually asleep
04:15 AM hypodyne: how did you go with your screw sorter?
04:40 AM rue_shop3: I found my unfinished new gear library that has a rack
04:40 AM rue_shop3: I am debating buying the woodgears.ca program to generate a new data set
04:41 AM rue_shop3: so far I think I'v done 18 circuit boards stripped down
04:42 AM rue_shop3: 6.5kg of parts
04:45 AM rue_shop3: one of the 3 boxes is actually starting to look low
04:47 AM Schrostfutz: Hi, I am working on programming a robot and have some problems with PID-controllers. I assemble the target (velocity, steering) vector based on potential fields. Should I use PID-controllers to dampen the result vector or should I do it for the individual behavior-vectors (e.g. the one that turns the robot to face a line it detected)?
05:08 AM rue_shop3: almost sounds like your trying to use pid for the wrong thing
05:09 AM rue_shop3: if you have a motor and a position/speed feedback sensor, you use pid to get the motor to the position/speed you want
05:09 AM rue_shop3: you can mungle it into doing something like line following, but
05:09 AM rue_shop3: what are you up to?
05:09 AM rue_shop3: its 2:39am and I'm going to bed
12:57 PM anniepoo: 8cD anybody up for doing 'hours'?
01:01 PM rue_house: just woke up
01:01 PM rue_house: trying to figure out how fingers work again
01:02 PM rue_house: nature is kinda messy, everything is everywhere
01:03 PM rue_house: I think I get it tho
01:03 PM rue_house: but there is still something missing
01:04 PM rue_house: ah there is it
01:05 PM rue_house: terminal tendon
01:07 PM rue_house: when I did the mecha finger
01:07 PM rue_house: http://ruemohr.org/~ircjunk/robots/sparrow1/p1070329.jpg
01:07 PM rue_house: I designed in skelatol limits
01:08 PM rue_house: it seems that was an error
01:09 PM anniepoo: hey
01:09 PM rue_house: it should be restricted by tendons between the sides of the joint
01:09 PM anniepoo: ok, weird factoid - when you pop your knuckles, you're expanding the sac around the joint
01:10 PM anniepoo: the lube in the joint has dissolved CO2
01:10 PM anniepoo: when you pull on the joint you enlarge the sac and the co2 comes out of solution,
01:10 PM anniepoo: the popping noise is bubbles
01:10 PM anniepoo: 8cD
01:11 PM rue_house: sounds plaudable
01:11 PM rue_house: I dont know why I just cant type on this keybaord and yet on the model M I'm just fine
01:11 PM anniepoo: ok, in the next hour I'll get simgoggles connecting to the db and display a list of bases
01:11 PM anniepoo: 8cD
01:11 PM rue_house: oooo
01:12 PM rue_house: I'm still stunned, I'm not sure
01:12 PM anniepoo: "rue will get unstunned and figure out what he's doing during the hour"
01:12 PM anniepoo: "rue will get unstunned and figure out what he's doing during the day"
01:12 PM rue_house: I should maybe weld tabs to the ...
01:12 PM rue_house: I should get dressed and eat.... breakfast
01:12 PM rue_house: (still in time)
01:13 PM rue_house: most diagrams 'take apart' the finger wrong
01:13 PM anniepoo: ok, Rue's going to get dressed and weld tabs to himself
01:13 PM rue_house: :/ someting like that
01:13 PM rue_house: simgoggles
01:13 PM anniepoo: I didn't know you were into physiology
01:14 PM rue_house: database tables?
01:14 PM rue_house: I have to, to make myself into a robot
01:14 PM rue_house: so I can exist for the next ~8000 years
01:14 PM rue_house: and see the supernova
01:14 PM rue_house: (one happened and the light is on its way)
01:14 PM rue_house: (its a ways out)
01:15 PM anniepoo: visualizer for our database - we (my day job) do 'anomalometry', which depends on a database we built that does correlation hella fast
01:15 PM rue_house: (I forgot which system, but there is lots of time to work that out again)
01:15 PM rue_house: ah
01:16 PM anniepoo: like, you can ask 'hey, what events are correlated with this really loud bang?'
01:16 PM rue_house: huh
01:16 PM anniepoo: 8cD we install this a lot on offshore oil rigs, where really loud bangs tend to involve lots of money and loss of life
01:17 PM rue_house: hmm, my experience is that the really loud bang isn't what you want to worry about, it'll be cheap to fix, the big concern is that little ticking noise, THEY cost a fortune when you find them
01:19 PM rue_house: ok, getting dressed... right
01:19 PM rue_house: findClothes();
01:19 PM rue_house: na
01:19 PM rue_house: 10 gosub findclothes
01:20 PM rue_house: 5 gosub pryassoutofchair
01:25 PM anniepoo: Schrostfutz - the latter, you need the PID to prevent oscillation of the steering mechanism
01:41 PM rue_shop3: that was 10:48 so goal is 11:48
01:46 PM rue_house: thanks
01:47 PM rue_house: finger, screw sorter, or pipe bender
01:47 PM rue_house: ?
01:47 PM rue_house: why idn't distracton an option?
01:47 PM rue_house: hmm
01:47 PM rue_house: led oscilloscope?
01:47 PM rue_house: nono
01:47 PM rue_house: awe cmon
01:48 PM rue_house: we need to make progress or you will never live to see the supernova
01:48 PM rue_house: ok ok
01:48 PM rue_house: if you want the candy, you have to do your choars first
01:49 PM rue_house: must be a better way to attack this hand
01:50 PM rue_house: the details of the hand do not matter, having any hand is whats important
01:50 PM rue_house: so, should we work on arm5?
01:50 PM rue_house: 5?
01:50 PM rue_house: 6, sorry, I meant 6
01:51 PM rue_house: you should work on the input system
01:51 PM rue_house: we need force sensors
01:51 PM rue_house: you gonna persue that foam thing?
01:51 PM rue_house: I'd prefer to get the piezo thing workable
01:51 PM rue_house: so 3d print a load cell
01:52 PM rue_house: a Z?
01:52 PM rue_house: you need something to start with
01:53 PM rue_house: dude, pneumatic load cell
01:54 PM rue_house: nono, go peizo
01:55 PM rue_house: a button load cell?
01:55 PM rue_house: I could entertain that
01:55 PM rue_house: square?
01:55 PM rue_house: did you have breakfast?
01:55 PM rue_house: se mepty bowl?
01:56 PM rue_house: yea, but I dont feel like I eaten
01:56 PM rue_house: so have lunch
01:58 PM rue_house: even if you had commercial load cells I think you still wouldn't know what do do to attack the force input thing
01:58 PM rue_house: hehe, shows you, I DO have some
01:59 PM rue_house: ok, I have an idea
01:59 PM rue_house: should I be worried
02:00 PM rue_house: WHAT did you do to my neck last night!?
02:00 PM rue_house: if I knew I wouldn't do it again, trust me...
02:02 PM rue_shop3: dude I got an idea!
02:02 PM rue_shop3: pneumatic force transfer
02:02 PM rue_shop3: that fixes the space problem with the force sensors!
02:02 PM rue_shop3: yea? yea?
02:03 PM rue_shop3: dude?
02:03 PM rue_shop3: hello?
02:03 PM rue_shop3: ...
02:05 PM rue_shop3: I need some really thin sheets of rubber
02:05 PM rue_shop3: I suppose rubber is like a resistor in a constant current circuit
02:05 PM rue_shop3: to a force system
02:15 PM rue_shop3: .
02:15 PM rue_shop3: anniepoo, your hours just about up
02:16 PM anniepoo: yup
02:16 PM rue_shop3: how did you do with the screen?
02:16 PM rue_shop3: :)
02:16 PM anniepoo: grrr... stuck on a bug
02:16 PM anniepoo: for some reason it's not loading my js
02:17 PM rue_shop3: whats the processsor?
02:18 PM anniepoo: i5
02:18 PM anniepoo: it's my desktop dev environment
02:18 PM rue_shop3: hmm, what browser?
02:19 PM anniepoo: I have a SWISH page, I have a cell with a script tag in it
02:19 PM anniepoo: chrome
02:19 PM anniepoo: http://swish.swi-prolog.org
02:19 PM rue_shop3: not heard of swish yet,
02:19 PM rue_shop3: another ajax like layer?
02:20 PM anniepoo: sort of
02:20 PM rue_shop3: do you know a silicone sealant that wont eat copper?
02:20 PM anniepoo: swish is an online programming environment for SWI-Prolog
02:20 PM rue_shop3: will it load ANY javascript?
02:20 PM anniepoo: rue - use a platinum based silicone
02:21 PM rue_shop3: oh I can get some at the gas station on the corner :/
02:21 PM rue_shop3: hmm
02:21 PM anniepoo: your sealant from a tube is inhibited with acetic acid (why it smells like vinegar) and that's what's attacking the copper
02:21 PM rue_shop3: yep
02:21 PM anniepoo: how'd you do?
02:21 PM rue_shop3: I dont think the latex stuff will do any better
02:22 PM rue_shop3: I ate, rice crispies
02:22 PM rue_shop3: and I'm not naked, so thats a plus...
02:22 PM rue_shop3: I'm designing a force sensor button
02:22 PM rue_shop3: to wrap a peizo disc in
02:22 PM rue_shop3: on your front, can you load any javascipt?
02:23 PM anniepoo: no, latex is same system
02:23 PM anniepoo: no - it's never making the http req for the script
02:23 PM rue_shop3: oh, can get wget the script from the server?
02:23 PM rue_shop3: oh wait
02:24 PM anniepoo: no, Im in html land
02:24 PM rue_shop3: heh, thought you said something else
02:24 PM anniepoo: oh, yes, if you put the uri for the script in the browser, it load it
02:24 PM anniepoo: so issue is in browser
02:24 PM rue_shop3: why would it not ask for the script...
02:25 PM rue_shop3: the script is in an incude?
02:26 PM rue_shop3: whats the html thats supposed to load the script?
02:26 PM rue_shop3: (telling me about it will probably make you realize whats going on)
02:26 PM anniepoo: yup
02:27 PM rue_shop3: I dont actually have to know anything
02:27 PM anniepoo: I once was working early, downtown SF - only other person at work was receptionist
02:27 PM rue_shop3: I just have to be here for you to expalin the problem in every newiance
02:27 PM anniepoo: so I went out to lobby and told her to nod her head and act like she understood
02:27 PM anniepoo: then I explained it, figured out issue
02:27 PM rue_shop3: :)
02:28 PM anniepoo: oh - UPS arrived with the down-looking camera for robot. I bought an OEM camera to use with my desktop as well, it's got a scary cool looking lens
02:29 PM rue_shop3: 180*?
02:29 PM rue_shop3: !?!?!.... pronterface crashed again...
02:29 PM anniepoo: nope
02:30 PM rue_shop3: OR... maybe I havnt' actually printed anything since the power bump!?
02:30 PM rue_shop3: oh god! I think I went 24 hours without printing anything!!!!!
02:30 PM anniepoo: crashes - either heat, inadequate noise caps, or mechanical?
02:30 PM anniepoo: LOL - yah, we're already talking about what sort of printer our second one should be
02:30 PM rue_shop3: it wasn't running
02:31 PM rue_shop3: just print one
02:31 PM anniepoo: cause we're needing more time
02:31 PM anniepoo: we could def. just copy the one we've got, but it'd be nearly as expensive, and time is money round here
02:31 PM rue_shop3: when I get going I could have 3 printers going
02:32 PM rue_shop3: I'm not sure more than that, it takes me a *little* while to design parts
02:32 PM rue_shop3: while true; do ./slic3r; done
02:32 PM rue_shop3: I worked out how to get around slicer crashes
02:33 PM rue_shop3: openscads CSG capabilites REALLY suck...
02:39 PM anniepoo: ok, this is stupid
02:39 PM rue_shop3: do tell
02:39 PM anniepoo: works if I insert the script, but not from src tag
02:40 PM rue_shop3: https://stackoverflow.com/questions/5436912/img-src-not-working-with-google-chrome
02:40 PM rue_shop3: pff
02:40 PM rue_shop3: k, lets try something else
02:41 PM rue_shop3: ad blocker?
02:43 PM rue_shop3: https://stackoverflow.com/questions/9689804/script-src-tag-issues
02:43 PM rue_shop3: ?
02:43 PM anniepoo: Ah!
02:44 PM anniepoo: it's swish's fault
02:44 PM rue_shop3: ok
02:44 PM anniepoo: The cell can contain script elements. The script elements are executed after the whole notebook is loaded and after editing the HTML cell and clicking outside the cell. First, the text of all script element without a lang attribute or lang="text/javascript" is collected. This is wrapped into an anonymous function with the argument notebook.
02:45 PM anniepoo: so by the time it actually displays the cell, the script tag is gone
02:45 PM rue_shop3: ok, so whats your next hour?
02:45 PM rue_shop3: I'm gonna hoggle-boggle assemble this load cell
02:47 PM anniepoo: ok, now that I understand how I should be doing this, I'm going to change it to cooperate with Swish's way of doing things
02:47 PM rue_shop3: its 12:16
02:47 PM anniepoo: 8cD
02:47 PM rue_shop3: and I'm gonna have lunch
02:51 PM rue_shop3: *OK*, man, prints take forever when you watch them
02:53 PM anniepoo: a watched print never comes loose and gums up the hot end
02:53 PM rue_shop3: hmm, what has thin copper foil...
02:53 PM rue_shop3: hahah
02:53 PM anniepoo: the tape you use for RF shielding?
02:53 PM anniepoo: you can get thin copper foil at JoAnn fabrics/Michaels type places
02:54 PM anniepoo: if you want really thin copper on mylar, buy a roll of copper metallic hot foil material
03:03 PM rue_house: ooh siwtching transformer shield
03:04 PM anniepoo: does it need to be copper?
03:04 PM anniepoo: brass shim stock?
03:04 PM rue_house: I need to connect with the peizo
03:04 PM rue_house: without causing a lump preferably
03:05 PM anniepoo: 0.001 shim stock
03:05 PM anniepoo: if you don't mind the delay I'd mail you some
03:05 PM rue_house: you nailed it
03:05 PM rue_house: not copper, brass
03:05 PM rue_house: not foil, chimstock
03:06 PM rue_house: 10 thou...
03:06 PM rue_house: https://www.fastenal.com/products/details/7041278?term=shim&r=~|categoryl1:%22603582%20Power%20Transmission%209and%20Motors%22|~%20~|categoryl2:%22600943%20Shims%209and%20Shim%20Stock%22|~%20~|categoryl3:%22604635%20Shim%20Stock%20Sheets%22|~%20~|sattr04:^Brass$|~
03:06 PM rue_house: $12
03:06 PM anniepoo: that's thicker than you want, I'd guess
03:07 PM anniepoo: and that's crazy - we bought a big assortment pack for $20 or under
03:07 PM rue_house: but I'm in canada!
03:07 PM rue_house: hmm
03:07 PM rue_house: I'll go find a transofrmer to tear apart
03:08 PM rue_shop3: haha
03:08 PM rue_shop3: oh yea
03:08 PM anniepoo: zoro.com
03:08 PM rue_shop3: I peel 2 sided pcb all the time for making single sided boards...
03:08 PM anniepoo: if you want it thinner - do you have rollers?
03:09 PM anniepoo: make a pile of sheets and put them thru all at once
03:09 PM anniepoo: then they still get thinner despite deflection of rolls
03:10 PM anniepoo: 8cD if you're good with a planishing hammer you can do like jewelers do
03:10 PM anniepoo: if you really want thin, use gold
03:10 PM rue_shop3: na, I just need to connect to the non-base side of the peizo without a lump
03:13 PM anniepoo: whats this for?
03:13 PM rue_shop3: 0.1mm
03:13 PM rue_shop3: you know a peizo element?
03:13 PM anniepoo: yes
03:13 PM rue_shop3: crystal on disc
03:13 PM anniepoo: sure
03:13 PM rue_shop3: so one lead is the disc
03:13 PM anniepoo: I mean what's application
03:13 PM rue_shop3: I need to connect to the other side
03:14 PM rue_shop3: but its a force sensor, so I need to keep the top connection flat
03:14 PM anniepoo: ah
03:14 PM anniepoo: consider household aluminum foil
03:14 PM rue_shop3: cant solder a wire to it
03:14 PM anniepoo: good point
03:14 PM rue_shop3: suppose I could just use a cap and 'spot weld' to it
03:15 PM rue_shop3: not sure what would stick
03:15 PM anniepoo: how would you attach the copper?
03:15 PM rue_shop3: charge cap, touch A to B
03:15 PM anniepoo: you can actually solder to rochelle salt
03:15 PM rue_shop3: *crack* welded
03:15 PM rue_shop3: ! wow
03:15 PM anniepoo: hmm...
03:15 PM rue_shop3: I'd like to try that...
03:16 PM anniepoo: I used to own a navy sonar transducer that was marked 'rochelle salt'
03:16 PM anniepoo: and had a wire soldered to it
03:21 PM rue_shop3: mental note: useless for spot welding it, but great way to EDM cut foil
03:22 PM rue_shop3: the pcb foil is 3 thou
04:11 PM rue_shop3: no, piezo crystals are NOT cut for verticle compression
04:11 PM rue_shop3: they must flex sideways somehow
04:12 PM rue_shop3: n --- U
04:12 PM rue_shop3: ( | )
04:12 PM rue_shop3: so squishing them --> | <-- that way generates no workable signal
04:51 PM mrdata: piezo crystal can squeeze multiple ways
04:53 PM mrdata: involves pretty specific geometry i think
04:56 PM anniepoo: I thought they bent
04:56 PM anniepoo: try exciting one with signal generator and using dial indicator on it
06:05 PM rue_shop3: I think I got it right on the second version
06:21 PM anniepoo: 8cD
06:21 PM anniepoo: which way is it?
06:44 PM z64555: had fun opening up a 4-stroke lawnmower engine today
06:45 PM z64555: but the part that I was supposed to be paying attention to, I didn't
06:45 PM z64555: I pulled out the camshaft for the valves before seeing if it had gotten out of alignment
06:54 PM SpeedEvil: Well, it's out of alignment now!
06:56 PM Tom_itx: it should be marked anyway
06:57 PM z64555: Yeah, the two spur gears have markings on them
06:58 PM z64555: there is no wear marks on the gears, so I can't tell if it had indeed slipped out of alignment or not
06:59 PM Tom_itx: how are they gonna slip?
06:59 PM Tom_itx: the gears are probably pressed on with a key
06:59 PM z64555: nope
06:59 PM z64555: plastic
06:59 PM Tom_itx: still should be keyed
06:59 PM z64555: One of them has a bump on it that sits in notch on the metal shaft
07:00 PM z64555: The other one appears to be casted directly on the shaft
10:14 PM rue_mohr: kinda at a crossroads between the pressure sensros I made from some antistatic foam I found, and the peizo ones I got working
10:16 PM codepython7771: anyone here? :)
10:17 PM anniepoo: yes
10:18 PM codepython7771: hi anniepoo
10:18 PM anniepoo: Giblets!
10:19 PM codepython7771: anniepoo: what are you working on?
10:20 PM anniepoo: right now, I'm in end of day mode, thinking about food and going home from the shop
10:20 PM anniepoo: I'd like to work on finishing the dancing robot, but right now I'm not feeling it. I'm pooped
10:21 PM codepython7771: https://www.pololu.com/product/713 - I was trying to figure out this board to control two small dc motors
10:21 PM anniepoo: spent all day tracing down what turned out to be an unannounced change in a protocol, so if you have two software systems running on diff versions of the only lib for it, you're hosed. 8c(
10:22 PM codepython7771: That can be annoying indeed
10:22 PM anniepoo: so, this seems straightforward to me
10:23 PM codepython7771: anniepoo: I've never used a board like this
10:23 PM codepython7771: anniepoo: what wires go where is what I need to figure out :)
10:23 PM anniepoo: https://www.pololu.com/file/download/TB6612FNG.pdf?file_id=0J86
10:24 PM anniepoo: looking at data sheet
10:24 PM codepython7771: I'm looking to run this with a 12v battery
10:25 PM anniepoo: so, to handle more current some pins are doubled
10:26 PM codepython7771: Do I have to give both vmot and vcc?
10:26 PM anniepoo: yes
10:26 PM anniepoo: Vcc drives the logic
10:26 PM anniepoo: Vmot supplies the motor current
10:27 PM anniepoo: give Vcc y5 volts
10:27 PM codepython7771: k - so vcc canbe given out at 3.3 from my nodemcu
10:27 PM anniepoo: this is a 5v logic device
10:28 PM codepython7771: 2.7 – 5.5 V for vcc, right?
10:28 PM anniepoo: nvm
10:28 PM anniepoo: page 3 (using page numbers on pages) says 3v typ
10:28 PM anniepoo: so give it the 3.3 off your mcu
10:29 PM codepython7771: where do the motors connect?
10:29 PM codepython7771: ao1, ao2?
10:29 PM anniepoo: yes
10:29 PM anniepoo: that's the first motor
10:30 PM codepython7771: ao1 and ao2 = 1st motor?
10:30 PM anniepoo: yes
10:30 PM anniepoo: two wires on motor
10:30 PM codepython7771: bo1 and bo2 = 2nd motor?
10:30 PM anniepoo: yes
10:31 PM codepython7771: PWMA and B to control speed then? 3.3V PWM?
10:31 PM anniepoo: with DC motors you don't have a center tap, so 3,4,9,10 are ust connected to - side of motor supply
10:31 PM anniepoo: suspect so
10:31 PM codepython7771: 3,4,9,10?
10:32 PM codepython7771: what is Ain1, Ain2 for?
10:32 PM codepython7771: separate power for motor a?
10:32 PM anniepoo: that's the logic to move the motors
10:32 PM anniepoo: it probably is hi or lo voltage to each side (that is ao1 and ao2)
10:33 PM anniepoo: so you'll freewheel the motor by setting Ain1=lo Ain2=lo
10:33 PM anniepoo: go one direction with Ain1=lo Ain2=hi
10:33 PM anniepoo: go otjer direction with Ain1=hi Ain2=lo
10:34 PM codepython7771: so forward reverse with flipping hi/lo? hi/lo= 3.3V?
10:34 PM anniepoo: yes, should just be a wire from the IO pin of the MCU
10:34 PM anniepoo: see bottom left of pg 3
10:37 PM codepython7771: cool
10:38 PM anniepoo: see top of pg 4 for explanation of logic
10:40 PM codepython7771: anniepoo: so STBY has to be high always?
10:41 PM anniepoo: I would guess so
10:42 PM anniepoo: yes
10:42 PM anniepoo: if you make it low, the motor is open circuit - last line of table on top of pg 3
10:42 PM anniepoo: if you make it low, the motor is open circuit - last line of table on top of pg 4
10:42 PM anniepoo: 4 not 3
10:43 PM codepython7771: anniepoo: so that means i am going to use 7 GPIO pins to control 2 motors? :)
10:43 PM anniepoo: do you need the standby function?
10:44 PM anniepoo: if you don't care about freewheeling, tie standby hi
10:45 PM anniepoo: and use an inverter to make Ain1 and Ain2 always opposite
10:45 PM codepython7771: so when stdby is low, the circuit is not drawing much power, correct?
10:45 PM anniepoo: correct
10:45 PM codepython7771: anniepoo: no harm in controlling that then
10:46 PM anniepoo: no harm
10:46 PM codepython7771: Thankfully the node has 16 gpio pins, so 7 is not that bad
10:46 PM anniepoo: whats the application?
10:46 PM codepython7771: trying to design a toy car :)
10:46 PM anniepoo: ok
10:47 PM codepython7771: two motors
10:47 PM anniepoo: so, will you be coasting the car?
10:47 PM codepython7771: just trying to program the node to make it do certain patterns?
10:47 PM codepython7771: for now
10:47 PM codepython7771: anniepoo: control its left, right speeds
10:48 PM anniepoo: you can control the motors with Ain0 and Ain1 - make them both low
10:48 PM codepython7771: not sure how to control it remotely yet...
10:48 PM codepython7771: I thought both low is stop?
10:48 PM anniepoo: it is
10:48 PM anniepoo: it's 'short brake'
10:49 PM anniepoo: the motor is shorted, it feeds back power and converts to heat
10:49 PM anniepoo: spin your motor with it disconnected
10:49 PM anniepoo: then short the terminals and try again
10:49 PM anniepoo: spins much easier with disconnected
10:50 PM anniepoo: you can also stop it just by not sending pulses
10:50 PM codepython7771: I was thinking of the later - pwm control
10:51 PM codepython7771: I want to do both cw and ccw, so i'll need to flip the in1/in2 to hi/low?
10:51 PM anniepoo: so, simplest, if your car doesn;t back up, is to wire Ain0 hi and Ain1 low.
10:51 PM anniepoo: yes, if you wnat both directions
10:52 PM anniepoo: if you don't care about brakes, you can just use an inverter and save pins
10:52 PM anniepoo: or just use more pins if you've got them
10:52 PM codepython7771: I need a 3.3v battery now
10:52 PM rue_house: wow thats a lot of questions for 1 motor driver
10:53 PM codepython7771: anniepoo: https://i1.wp.com/henrysbench.capnfatz.com/wp-content/uploads/2016/09/Power-ESP-12E-with-a-9V-Battery.png?w=706
10:53 PM anniepoo: ok
10:53 PM rue_house: you cant power your motor thru the arduino regulator...
10:54 PM anniepoo: yup, you can't power your motor thru the arduino regulator
10:54 PM codepython7771: looking what voltage range nodemcu takes
10:54 PM rue_house: (even if its not an arduino)
10:54 PM anniepoo: rue, how much power will that bluetooth take?
10:55 PM rue_house: hmm, by that battery? I'd guess about 8 minutes worth
10:56 PM codepython7771: nodemcu takes 5 to 10v :)
10:56 PM rue_house: I wonder what the 20 hr rate is for one of those
10:56 PM codepython7771: so i could drive the whole thing with 1 battery
10:56 PM codepython7771: 9v
10:57 PM rue_house: yes
10:57 PM rue_house: the pressure is right, but the tank isn't verry large
10:57 PM rue_house: what size motors are you using?
10:58 PM codepython7771: rue_house: i've old brushed motors, small ones. Not sure about the specs.
10:58 PM rue_house: ok
10:58 PM rue_house: have a picture?
10:58 PM codepython7771: They do work at 6 to 9v, high rpm
10:59 PM rue_house: k
10:59 PM rue_house: two motors then, right?
10:59 PM codepython7771: yes
10:59 PM rue_house: wheeled robot?
11:00 PM * rue_house looks to anniepoo
11:00 PM codepython7771: rue_house: yes
11:00 PM rue_house: ?
11:00 PM anniepoo: yup
11:00 PM rue_house: you using arduino stuff to code it?
11:00 PM codepython7771: rue_house: esp8266 - similar to arduino
11:01 PM rue_house: yea, you can use the arduino ide on them iirc
11:01 PM codepython7771: Thinking of using 2 x 18650 batteries.
11:01 PM rue_house: they would hold about 4x more power than a 9V
11:01 PM rue_house: atleast
11:01 PM codepython7771: need a case for them
11:01 PM anniepoo: ok all, I'm headed home
11:02 PM rue_house: gnight
11:02 PM anniepoo: probably via subway, sammich time
11:02 PM codepython7771: anniepoo: thanks for the help. :)
11:02 PM rue_house: codepython777, so, what are you using to program them anyhow
11:02 PM codepython7771: rue_house: python :)
11:02 PM rue_house: ugh
11:02 PM anniepoo: you're in good hands with rue
11:02 PM rue_house: k
11:03 PM rue_house: does the python stuff you have, have an io library for pwm etc?
11:03 PM codepython7771: rue_house: yes. The only problem is, sometimes i've to reboot it to make things work. Looks a little unstable.
11:04 PM rue_house: huh
11:04 PM rue_house: lack of capacitors
11:04 PM rue_house: might be as sensitive as a PIC
11:04 PM rue_house: hopefully not
11:04 PM codepython7771: not sure, i was powering them with usb
11:05 PM codepython7771: sometimes the usb connection sstarts acting up
11:05 PM codepython7771: reboot and things work
11:05 PM rue_house: so, anniepoo got you all wired up then eh?
11:05 PM codepython7771: rue_house: I still have to do some soldering :)
11:05 PM codepython7771: that board is small...
11:06 PM codepython7771: and i need 2x18650 series box if i can buy one
11:06 PM rue_house: heh, thats not small
11:06 PM rue_house: ebay $1.50
11:07 PM codepython7771: rue_house: http://www.ebay.com/itm/2X-Series-18650-Li-Ion-Battery-8V-Holder-Case-Clip-Box-with-6-Wire-Leads-US-/192176942843?hash=item2cbea36efb:g:H~0AAOSwX61ZClWr ?
11:08 PM rue_house: I'd get it from china, but yea
11:08 PM codepython7771: what is a good charger to buy for 18650?
11:08 PM rue_house: http://www.ebay.com/itm/6-Pcs-Black-Plastic-2-x3-7V-18650-Type-Battery-Holder-Box-Case-LW-/181775746575
11:08 PM rue_house: just so you know what they usa markup is
11:09 PM rue_house: dunno about charger, no
11:11 PM codepython7771: rue_house: thanks
11:11 PM rue_house: http://www.ebay.com/itm/DC-Battery-Box-Case-Storage-Holder-ON-OFF-Switch-Wire-for-2x-18650-3-7V-Battery-/272592132462
11:11 PM rue_house: thats got a switch
11:12 PM codepython7771: rue_house: I need a 36V 20A switch - any pointers? Just simple on/off
11:13 PM rue_house: just on and off?
11:13 PM codepython7771: yes.
11:14 PM codepython7771: Also for this one, do i need to get low voltage alarm? For the 2x18650s?
11:14 PM rue_house: http://www.ebay.com/itm/Auto-Car-Toggle-switch-SPDT-ON-OFF-ON-3Pin-3-Position-12V-25A-/142432013007
11:14 PM rue_house: you shoudl ahve a battery controller board yea
11:14 PM rue_house: for li=ion
11:15 PM rue_house: otherwise the batteries may not last long
11:15 PM codepython7771: rue_house: 3 positions? I just need on off :)
11:15 PM rue_house: http://www.ebay.com/itm/12V-25A-On-OffCar-Auto-Blue-LED-Toggle-Switch-Carbon-Fiber-Aircraft-Flick-Cover-/162531608595
11:16 PM codepython7771: rue_house: for 2 x 18650, what bms / voltage alarm do i need?
11:17 PM rue_house: the extra money is worth the extra price
11:17 PM rue_house: er, damn
11:17 PM rue_house: the coolness factor is worth the extra price
11:17 PM codepython7771: you mean for that switch? :) coolness factor?
11:18 PM rue_house: http://www.ebay.com/itm/2S-BMS-PCB-Protection-Board-for-2-Packs-18650-Lipo-Li-ion-Lithium-Battery-Cell-/191973138636
11:19 PM rue_house: http://www.ebay.com/itm/2-Cell-8A-7-4V-8-4V-Lithium-LiPo-Cell-Li-ion-BMS-Battery-18650-Protection-Board/282475655380
11:19 PM rue_house: there is that too
11:20 PM codepython7771: rue_house: most of these are showing welded nickel plates...
11:21 PM rue_house: na you can just solder wire
11:22 PM codepython7771: I see
11:23 PM codepython7771: rue_house: How does one handle grounding on a high voltage robot?
11:23 PM rue_house: ?
11:23 PM rue_house: high voltage?
11:23 PM codepython7771: rue_house: So if my battery is 36V, with a XT60 - how does grounding work? These switches seem to have grounds - 3 pin connctions?
11:23 PM codepython7771: high voltage = 36v
11:23 PM rue_house: no
11:24 PM rue_house: make the - a common line between everything
11:24 PM rue_house: otherwise no grounding
11:24 PM codepython7771: I'm using one battery, that drives two 36v motors - so no grounding?
11:25 PM rue_house: yea, your not using a seperate battery for that controller are you?
11:25 PM codepython7771: k - i'm talking about two different applications
11:25 PM rue_house: good good
11:25 PM rue_house: sorry, I'm falling asleep
11:26 PM codepython7771: One is a 36V with bldc. One is a 9v one with two brushed dc motors
11:26 PM codepython7771: rue_house: have you used a bms yet?
11:26 PM rue_house: I wonder how the radio takes to the brushed motors...
11:26 PM rue_house: no, I have one planned for a robot I'm making
11:27 PM rue_house: 320W dc-dc + balancer
11:27 PM codepython7771: radio talks to the brushed motor?
11:27 PM rue_house: 24V, 18A 48 cells total
11:27 PM codepython7771: rue_house: you would need a nickel strip and spot welder?
11:27 PM rue_house: no, but the brushed motor does a lot of RF screaming
11:28 PM rue_house: no, just solder is fine
11:28 PM codepython7771: at those amperages?
11:28 PM codepython7771: what max amperage are you planning to pull?
11:28 PM rue_house: hmm, where did my esp8266 go? that could be an amusing project
11:29 PM rue_house: must be in the bag of goodies
11:29 PM codepython7771: what do these BMSes do when the battery drops - cut power off?
11:29 PM rue_house: yup
11:30 PM codepython7771: once i solder them, how do i charge them?
11:30 PM rue_house: you ..you dont solder tot eh cells
11:30 PM rue_house: you use the hodler for the connections
11:31 PM rue_house: if your making a pack you weld to the batteries
11:31 PM codepython7771: rue_house: http://i.ebayimg.com/images/g/uCcAAOSwGtRX0ZZH/s-l500.jpg
11:31 PM rue_house: for direct battery connection, soldering applies too much heat, thats why their welded
11:31 PM rue_house: yea
11:31 PM rue_house: those are tabs
11:31 PM rue_house: so that the battery dosn't get overheated
11:31 PM codepython7771: those are welded to the battery, right?
11:31 PM codepython7771: the strips
11:31 PM rue_house: yup
11:31 PM rue_house: tabs
11:31 PM codepython7771: how does one charge this ?
11:32 PM rue_house: those top connectios
11:32 PM codepython7771: just push 9v inside it ?
11:32 PM rue_house: cause the output connections are in the middle of that pcb
11:32 PM rue_house: not 9V no
11:32 PM rue_house: constant current, voltage limited
11:32 PM rue_house: thermally proteced
11:33 PM rue_house: you HAVE to be nice to li-ion, or it explodes
11:33 PM codepython7771: I've a lipo charger
11:33 PM codepython7771: but then i'll have to get a balancer out
11:33 PM rue_house: use it, use the pack
11:33 PM rue_house: take the battereis out to charge
11:34 PM codepython7771: http://i.ebayimg.com/images/g/uCcAAOSwGtRX0ZZH/s-l500.jpg - this is not coming out
11:34 PM codepython7771: you are saying, just solder to the wires of the enclosure?
11:34 PM rue_house: batteris -> holder -> bms -> robot
11:35 PM rue_house: its a hobby project, not a industrial tool
11:35 PM rue_house: oooh so many distractions
11:37 PM codepython7771: I see - so the holder is soldered to the bms?
11:37 PM rue_house: thats what I suggest
11:37 PM codepython7771: bms out goes to robot
11:37 PM codepython7771: sounds clean
11:37 PM rue_house: bms needs to be on the robot
11:37 PM rue_house: to turn the power off if they get too low
11:38 PM codepython7771: http://i.ebayimg.com/images/g/uCcAAOSwGtRX0ZZH/s-l500.jpg - so in this image, i dont need the top two red/black wires
11:38 PM codepython7771: since i take them out and charge
11:41 PM codepython7771: rue_house: http://www.ebay.com/itm/Xtar-VC2-USB-Li-ion-Battery-LCD-Charger-For-3-7V-10440-18650-26650-Batteries-/151695112521?hash=item2351bbb949:g:IxgAAOSwZ4dZEJJE
11:50 PM rue_house: sure