#robotics Logs

Nov 15 2015

01:59 rue_shop3 :) I fixed the washing machine!
02:00 robopal oh great, now I need you to come and fix mine, pump stopped working
02:01 rue_shop3 full of hair
02:01 rue_shop3 have fun
02:53 Anniepoo 8cD
02:53 Anniepoo mine's full of foam rubber dust. Will you come fix mine?
02:59 rue_shop3 root@blackie2:/tmp# ohm -v 0.7 -i 0.02
02:59 rue_shop3 Wattage is: 0.014000
02:59 rue_shop3 Current is: 0.020000
02:59 rue_shop3 Voltage is: 0.700000
02:59 rue_shop3 Resistance is : 35.000000
02:59 rue_shop3 35 eh...
03:00 rue_shop3 er, thats not right
03:00 e_shop3 teaches himself how to make a current so
03:01 niepoo is here, with a battery charger and a bucket of water
03:02 rue_shop3 arg, I needa current source to bias the votlage for my current source
03:03 rue_shop3 hmm .9V
03:03 rue_shop3 where am I gonna get taht
03:42 rue_shop3 ok I ahve a capacitor to charge
03:44 rue_shop3 its 330pF
03:44 rue_shop3 and I want to charge it to 10V
03:45 rue_shop3 and I want it to take 0.1us
03:45 rue_shop3 so, what current to I need to charge it with?
03:46 anonnumberanon * rue_shop3 teaches himself how to make a current source
03:47 onnumberanon 's interests are being pertaine
03:47 rue_shop3 I did it, I used an LED as a source regulator
03:49 rue_shop3 hmm 34mA
03:50 rue_shop3 great, my driver needs a driver
03:51 rue_shop3 but wait, I can use a low side fet driver cause of my new design
03:51 rue_shop3 ok, throw out everything and start AGAIN
03:52 anonnumberanon do it
03:52 anonnumberanon DO SOMETHING
03:52 anonnumberanon for me it's brainstorming time
03:59 rue_shop3 ADP3418
03:59 rue_shop3 I think its a low side fet driver
04:00 rue_shop3 Dual Boostrapped 12 V MOSFET Driver With Output Disable
04:00 rue_shop3 I think thats high side
04:02 rue_shop3 agkh, its smart. dont want that
04:02 akem hola
04:04 akem i hope my arduinos will be fucktionnals on my new win8 tablet
04:05 akem maybe i should pray the god of compatibility
04:08 anonnumberanon https://www.youtube.com/watch?v=iuMngik0GR8
04:15 rue_shop3 max662?
04:15 rue_shop3 nope
04:16 rue_shop3 what did I do with ALL the low side drivers from ALL these motherboards?
04:16 rue_shop3 HIP6603
04:19 rue_shop3 still more complex than I want
04:32 Manuel_ I'm searching for grasping framework, any hints?
04:41 rue_shop3 FAN5009, but they aren't quite what I want
04:42 rue_shop3 you mean you want a gripper?
04:42 rue_shop3 do you want to buy it or make it?
05:15 anonnumberanon Prolly gonna order a couple HEF4067B for servo outputs. 16 outputs each, reacts in 15us. Should allow me to use up only 5 pins of the atmega328p.
05:16 SpeedEvil There are also nice SPI/I2C GPIO chips that you may consider using that are useful and very flexible.
05:18 rue_shop3 ya know, if I would just accept making this a 40Khz converter instead of a 250Khz, I could be done
05:19 rue_shop3 anonnumberanon, seriously? a mux?
05:19 rue_shop3 tell me this,
05:19 rue_shop3 what is the min and max pulse time to a servo?
05:20 anonnumberanon 1 to 2 ms
05:20 rue_shop3 ok and what is the time between pulses
05:22 rue_shop3 it clicked didn't it?
05:22 anonnumberanon Well for that I'd have to know what the servo is comfortable with receiving. I'm not sure.
05:22 rue_shop3 50Hz
05:22 rue_shop3 so, how much time between pulses
05:23 anonnumberanon 1/50
05:23 rue_shop3 which is? in ms...
05:23 anonnumberanon 20 miliseconds
05:23 rue_shop3 ok
05:24 rue_shop3 so how many servos can you do before you have to start doing the first one again, worst case?
05:25 rue_shop3 well?
05:26 anonnumberanon 17 servos * 3.75 * 5 = time to send pulses to all servos = 320us
05:26 anonnumberanon This would be without counting the time the micro takes to flip ports on and off.
05:26 rue_shop3 how about 20ms/2ms = 10
05:26 anonnumberanon and flipping a port takes 200 ns
05:26 rue_shop3 dont confuse latency for frequency
05:27 rue_shop3 10 servos
05:27 anonnumberanon You're talking about the demultiplexor switch time?
05:27 rue_shop3 2ms 2ms 2ms 2ms 2ms 2ms 2ms 2ms 2ms 2ms
05:27 rue_shop3 then you have to start a new pulse on the first one again
05:28 rue_shop3 so you cant reach the 11th one, there is no time
05:28 rue_shop3 (worst case)
05:28 anonnumberanon Ah I see what you mean why demux is not the right idea.
05:28 anonnumberanon LOL
05:28 rue_shop3 you could just say that all servos cant be at the 2ms mark at once tho
05:28 rue_shop3 look at the 4017
05:29 rue_shop3 its whats called a ripple counter
05:29 rue_shop3 every time you pulse it, the next output turns on
05:29 rue_shop3 so you time your pulses
05:29 rue_shop3 all you need is 1 pin,
05:29 rue_shop3 if the servos times are supposed to be 1ms 2ms 2ms 1ms
05:29 rue_shop3 you make that the timing of the pulses on the one pin
05:30 rue_shop3 if you want to make sure of what servo your on, you can set up the reset pin
05:30 rue_shop3 that takes 2 io for up to 10 servos
05:30 e_shop3 goes back to his power conve
05:31 anonnumberanon wait i need to understand how that 4017 works
05:31 onnumberanon reads the sheet of
05:31 rue_shop3 pdf download CD4017
05:32 rue_shop3 http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
05:32 rue_shop3 I'm sure you didn't read that before and I'm sure you wont read over it now
05:54 anonnumberanon What the heck is an sm0vpo?
06:00 anonnumberanon oh that must be a name of a guy who drew the schematics
06:42 rue_shop3 its 4:30am
06:42 rue_shop3 I been working on my power supply for 14 hours stright now
06:43 rue_shop3 I'v tried every fet driver configuration I could find
06:43 rue_shop3 and whats funny
06:43 rue_shop3 whats really really funny
06:43 rue_shop3 is what worked best
06:43 rue_shop3 the best fet driver is
06:43 rue_shop3 (drumroll)
06:43 rue_shop3 LM555
06:44 rue_shop3 the 555 can convert the 5V input signal to 12V, and drive the power fet thru the level converter (cap)
06:45 rue_shop3 an AOP605 fet totem pole driver will help IF I get about a 14-16V supply for it
06:45 rue_shop3 cause it loses 2V
06:47 anonnumberanon "All the pulse are generated in sequence on the PWM pin, then spread out to the individual servos via the decade counter. The decade counter costs 63 cents. "
06:47 anonnumberanon :) yes pls?
06:52 rue_shop3 sounds right
06:52 rue_shop3 $0.63 sounds a bit high
06:53 rue_shop3 http://www.aliexpress.com/item/Free-shipping-100PCS-CD4017-CD4017B-CD4017BE-4017-DECADE-COUNTER-DIVIDER-IC/32229184373.html
06:53 rue_shop3 7c ea sounds right
06:53 rue_shop3 1000 servos for $7
06:55 anonnumberanon lol
06:55 anonnumberanon ill go check the 74HC4017
06:55 anonnumberanon also i need the parts super fast because I am moving fast at the moment
06:57 anonnumberanon I'd order 3, to use 4 microcontroller pins. One connected to all three resets and the other 3 to clock, or vice versa not sure yet. Unless I'm not understanding this correctly but I think I am.
06:57 rue_shop3 $8 next day shipping, chips are 0.75 ea http://www.digikey.ca/product-detail/en/CD4017BE/296-2037-5-ND/67253
06:58 rue_shop3 yup, you still cant do perfect timing of more than 8 servos at once
06:58 anonnumberanon how perfect are we talking about? some jitter?
06:59 rue_shop3 4ns or so
06:59 rue_shop3 it causes noticable twitch in a good servo
07:00 anonnumberanon Okay my previous solution to send 4 outputs to 4 quadcopter ESCs has an overall jitter of up to 30us.
07:00 anonnumberanon This would be negligible in comparaison.
07:00 rue_shop3 atmega328 are $3 ea as arduino boards, each run 8 servos with perfect timing with 32 servos (4 mega328s) on one 9600 baud serial bus
07:00 rue_shop3 0ns jitter
07:01 rue_shop3 with 24000 counts of position per servo
07:01 e_shop3 watches anonnumbera
07:02 anonnumberanon Well I do have atmega328 chips.
07:02 anonnumberanon Not even need to order boards.
07:02 rue_shop3 with the arduino baords, you dont have to add the crystal and reset circuitry and programming header
07:02 anonnumberanon that serial bus you send it to one arduino? or all of them share the same?
07:03 rue_shop3 yup, you program each controller with a different address range
07:03 rue_shop3 0-7 8-15 16-23 24-31
07:03 anonnumberanon THING IS
07:03 e_shop3 sm
07:03 rue_shop3 ?
07:04 anonnumberanon im sending the servo positions from this remote control that I just built, using wireless chips, so no serial (even though it would be nice to still use serial for other stuff but that is irrelevant).
07:04 anonnumberanon I have thus two pressing tasks.
07:05 anonnumberanon First, to measure the time between each reception of servo position command from the wireless chip, and hope it's like half a miliseconds.
07:05 anonnumberanon task 1.5: check if that time increases as I move the remote control away
07:06 anonnumberanon task 2: if task one ends up showing that kinda wireless thing takes way too much time (like 2ms or something like that), painfully rewrite the huge wireless library I have been using.
07:08 anonnumberanon Well so far, and the following statement may not be accurate because I am a human, moving the joystick on the remote control seems to have a real time effect on the position of the servo.
07:08 rue_shop3 your converting FROM RC pulses?
07:09 anonnumberanon not RC, kinda RC, I'm sending integers over radio, some radio chips that I pair to the atmega328s.
07:09 rue_shop3 hmm
07:10 anonnumberanon the receiving radio chip is not getting a pulse, just an integer (the position from like 0 to 1000 of the servo).
07:10 rue_shop3 gngiht!
07:11 rue_shop3 its 5am!
07:11 anonnumberanon I should bed too.
07:11 anonnumberanon sigh
13:19 Infester any good intro to robotics links?
13:20 ace4016 http://www.seattlerobotics.org/gettingstarted.php ?
13:21 ace4016 it's a fairly big and varied field that applies other fields to it (it has a lot of foundations, some of which you may or may not use)
13:46 Infester yeah, i was trying to find something i could play around with building on my Rpi
13:48 ace4016 there are some RPi robot kits about you can look into
13:48 ace4016 unless you want to build from scratch
14:27 Loshki Infester: I like "Raspberry pi cookbook" but there are a million sites out there: start reading...
14:28 Loshki Oh, you specifically wanted robots: http://www.instructables.com/id/Building-robots-with-Raspberry-Pi-and-Python/
15:36 maiden hmm
15:37 maiden I guess you have heard of Q-Learning before, but have you heard about "Two Mode Q-Learning"?
15:37 maiden http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.551.4980&rep=rep1&type=pdf
15:39 rue_house hahaha you need an arduino to operate your Pi controlled robot
15:41 robotust1a I doubt that your robot with Q-learning will walk like this robot https://www.youtube.com/watch?v=-Vg-BdXps50
15:43 rue_house well done
15:43 robotust1a because it's a neural network
15:45 robotust1a it's not Zero Momentum Point
15:45 rue_house atleast it dosn't have to dance when it stops
16:14 akem lies
16:15 veverak nah
16:16 veverak :)
16:31 akem what about roomba like robots using copter drones flying powers to remove dust and spider webs on the ceilling
16:32 akem with roof detectors it may not exist yet
16:32 akem rotating brushes, even in japan
16:33 veverak hmm
16:34 veverak I have value 'actual' and 'target' and I need to change actual so it's closer to target
16:34 veverak with limitation of "max_step" being proportional to time that passed since last change of value
16:35 veverak any tips for implementation that got this effective in C?
16:35 verak did soemthing, but it's not sure it's as effective as it coul
16:37 rue_house I think the FCAA made indoor autonomous drones illegal too
16:38 rue_house veverak, servo code?
16:38 veverak RGB leds
16:38 veverak :)
16:38 rue_house oh
16:38 rue_house just interpolation then
16:38 rue_house yea
16:38 rue_house use my interpolator libray
16:38 veverak also
16:38 rue_house it can handle up to 65536 channels
16:38 veverak not sure if FastLED doesn't allready poses such a thing
16:39 rue_house my interpolator uses callbacks
16:40 rue_house you set up all the axies positions and targets, give it access to the fn's to change each channel and a 'sync' fn that determines timing, it does all the work
16:40 veverak http://pastebin.com/727GG73m
16:40 veverak but nah, not sure if everything is 'understanble' from the code itself
16:40 rue_house it linearly interpolates all the channels for you
16:41 rue_house http://ruemohr.org/~ircjunk/robots/arm9/roboplayer.tgz
16:41 rue_house look at 'interlin.c'
16:42 rue_house SimotaniouslyLinearlyInterpolateMultiAxis(
16:43 maiden robotust1a: this was impressive! https://www.youtube.com/watch?v=8uiPHL-xey4
16:43 rue_house my appologies, the app note at the bottom of the code isn't up to date,
16:43 maiden i would love to see that source
16:43 rue_house currently it calls back with a float of the new postion to set
16:49 rue_house veverak, how many rgb leds?
16:49 veverak 150
16:49 rue_house yea, no problem
16:50 rue_house linear brightness change of each led on an individual basis from the old to new values
16:50 rue_house its only 450 cahnnels
16:51 rue_house 65086 channels to spare
16:52 rue_house I think you will find the use of the interlin functions in the spooler code
16:53 veverak thanks
16:54 robotust1a maiden: yes, this Dr.Guero is a real pro
16:59 maiden robotust1a: i wonder what sensors he is using.
16:59 maiden i doubt its only a gyro/accelerometer
17:00 robotust1a I think there are a couple
17:00 maiden the way "bigger" humanoids handle force/torque is with force/torque sensors in the feet/ankles
17:01 robotust1a but as for me - 1 gyro would be enough
17:01 maiden would you be able to handle uneven floor / stairs / steps with only a gyro?
17:02 maiden you need to be able to detect the angle of the contact area and the difference between ground and a wall ^_^
17:12 robotust1a angles - yes
17:13 robotust1a but it's easy to do
17:13 robotust1a you change the angle and measure acceleration
18:32 verak started to organize ideas about his proj
18:33 veverak counted 6 projects
18:33 veverak didn't get to "software only projects" yet though
18:33 veverak nah, tomorrow :)
20:53 orlock https://www.youtube.com/watch?v=Slq_ag38eKc
21:50 anonnumberanon I hear talk about God Guero?
21:57 anonnumberanon I'm also waiting to implement his robot with flexible arms. He took a few shortcuts by giving them each only one degree of freedom. I would love to see how it fares in a robot fight as well.
21:59 anonnumberanon He probably does the PID correction with two directions, left and right with the arm, and front and back with the actual legs. The leg part is harder, the arms must be a bit trivial.
23:23 anonnumberanon veverak, what are the 6 projects?