#robotics Logs

Dec 07 2015

01:07 rue_bed at the rate monitors are going, new age monitors wil be 4 lines by 60000 pixels, as a 48" screen
02:09 Jak_o_Shadows I dunno, those widescreen monitors are nice
02:17 maiden morning
02:38 maiden lolilol, had to boot an old computer in order to get internet to my RPI.. gotta find my wifi dongle..
05:52 cyber37 Hi, i need to know something, on a DC motor, how is called the axis type ? for exemple there is motor with a square on the axis, and there is motors with a plane part in the axis, how is that called ? I have a motor with a plane part in the axis and i want to be able to put a sprockle on it, but i have to find the good one so ..
06:04 SpeedEvil do you mean the shape of the spindle?
08:39 veverak :)for that moment
08:39 veverak when you got tons of things to do
08:39 veverak and you discover interesting topic concerning robotics
08:39 veverak damn it
08:48 deshipu veverak: how is it going?
08:49 veverak deshipu: finally going to brno to get battery
08:49 veverak also, micropython for esp8266 is ready
08:50 veverak not tested yet though, have to make pinout from esp I've got
08:50 veverak + got 3D model of exactly the version I've got :)
08:51 veverak (and to practice C, I thought about making simple collision models for legs ... )
08:51 veverak (with ROS it should be possible to run program on laptop to make sure walking algorithms won't cross the legs)
08:52 veverak also, thanks to 3d models I can setup constants for your arduino code
08:53 veverak I've got different length of tibia thanks to 3d printed parts
08:57 deshipu I couldn't get the walking code run on esp8266, too little free memory
09:00 akem hey deshipu
09:01 deshipu hi akem
09:02 akem deshipu toying with wifi?
09:03 deshipu not really
09:03 deshipu just robots
09:09 akem deshipu ok, esp8266 is wifi module right?
09:11 deshipu akem: yes, but it's also programmable
09:11 deshipu akem: so you can use it as a brains of your robot
09:11 deshipu akem: and you have remote control for free!
09:12 akem deshipu cool
09:13 robotustra morning
09:13 deshipu good afternoon :)
09:16 veverak deshipu: yeah, but that's motivation for ROS
09:16 veverak it should be able to run the robot app on two machines at once ...
09:17 veverak (with proper consequences ofc)
09:25 robopal can you place a ban on ntrnflxlbs?
09:26 rue_house deshipu, too little memeory or too bloated software?
09:43 robotustra robopal: add it to ignore
09:46 SpeedEvil It's been klined
09:52 deshipu rue_house: both
10:28 SpeedEvil http://xkcd.com/
10:52 veverak awesome
10:52 veverak deshipu: can now track position of any point on the 3d model
10:53 deshipu track?
10:53 veverak got coordinates of any child of any object relative to that object
10:53 deshipu as in, forward kinematics?
10:53 veverak after I feed calculated angles into 3d models
10:53 veverak *3d model
10:54 veverak "target point -> get angles for servo -> find points in model and tell me coordinates"
10:54 deshipu ok, now just add also tracking speeds and accelerations
10:54 deshipu and add inertia
10:55 veverak would that be of any specific use?
10:56 verak now wants to finish it in a way, that it will automatically be able to calculate constants for inverse kinema
10:56 veverak "leg length" etc...
10:57 veverak idea is that as long as you change robot construction AND change the model accordly you don't have to calculate those manually
10:57 veverak and also because it's fun
13:16 anonnumberanon akem, take back what i said about running multiple servos you can only run about 4 to 6 with atmega328p. I was running 12 but some of the signals got interference with one another.
13:17 robotustra leggedless robots rules
13:21 Snert_ unless it's a stepford wife :)
13:21 Snert_ lol
13:21 Snert_ that was a cool show. ahead of it's time it was.
13:22 akem anonnumberanon really, signal interferences? like using all the digital out pins of the board, each one controlling a separate servo?
13:25 anonnumberanon akem, in some instances you change the signal on one and it affects the other(s), sometimes it even sets the pin high without any kind of signal at all. When I discovered that my spirit was crushed lol.
13:27 maiden anonnumberanon, you need: https://www.pololu.com/product/207
13:27 maiden used that with a arduino mini pro to build a small humanoid with micro servos
13:28 akem anonnumberanon are you sure your board is not broken? :)
13:29 maiden indeed, it should not be an issue.
13:29 anonnumberanon maiden, not invented here
13:29 akem or some libraries/codes borked up
13:29 maiden or maybe you used to much power so your system became unstable?
13:29 anonnumberanon besides i already got the 4017 backup solutions which is working at the moment for 8 servos
13:29 maiden what battery/power supply did you have and what servos did you use?
13:30 veverak http://i.imgur.com/isKMqoX.jpg
13:30 veverak finally proper foto
13:30 anonnumberanon i had separate microcontroller and servo power power supplies so that should not be an issue
13:31 maiden aw, cute!
13:31 robotustra don't listen to him, build big humanoid robot, like real man
13:31 anonnumberanon i was worried about 12 signals sent through the digital pins being more than the micro can handle though but that happened even when the pins were not connected to anything and were thus not drawing any current
13:31 veverak nah
13:31 maiden veverak, have been thinking of building a quad, but with wheels on the legs so it can walk and drive :D
13:31 veverak humanoid robot sucks :)
13:31 veverak maiden: know logicoma?
13:32 veverak deshipu is building one :)
13:32 maiden https://www.youtube.com/watch?v=dargOslomMA
13:34 Snert_ maiden: so cute!
13:34 maiden indeed, its an awsome build
13:35 anonnumberanon not enough power :(
13:35 anonnumberanon amp up the stakes!
13:35 anonnumberanon if(bot < 100){design again}
13:35 anonnumberanon :) :) :)
13:35 maiden units plz
13:36 maiden 100ug?
13:36 anonnumberanon 100 watts sorry lol
13:36 maiden 100mm?
13:36 maiden hehe, i will make a mini sumo that consumes 100W for you ;)
13:36 maiden massiv heatbed as case :p
13:37 anonnumberanon nah lol it has to be all motor wattage
13:37 anonnumberanon and spinning heavy wheels for no reason does count
13:37 anonnumberanon not count
13:37 maiden so no 100W dildo :(
13:37 veverak it's not abou the size!
13:37 veverak but cuteness
13:37 veverak :)
13:40 anonnumberanon veverak, size has nothing to do with power
13:40 veverak size/power same
13:41 SpeedEvil Volume * RPM is pretty closely tied to power actually, for any given type of motor
13:41 anonnumberanon power is force times speed
13:42 maiden sure?
13:42 SpeedEvil Sure. But in terms of practical motors.
13:43 anonnumberanon all im saying is with power you make fast and strong robots
13:43 SpeedEvil This is due (amongst other things) to the constant energy per volume of magnets.
13:43 robotustra I'm configuring 160W rf dildo
13:43 robotustra now
13:44 anonnumberanon for example that takichoma in the video is slow when walking, if pulling weight, as well, it would struggle while on its wheels
13:56 maiden robotustra, remember, what its force times speed not size that matters ;)
13:56 robotustra sure
13:56 robotustra P=F*v
13:57 maiden but i like P = U * I better..
13:58 robotustra I like W=(C*U^2)/2
13:59 robotustra or even (C*U^2)/(2*dt) where dt->0
13:59 maiden but everyone knows that real numbers are for sissies..
14:00 robotustra exactly
14:00 robotustra looking for relay which has 2 groupe of contacts
14:01 robotustra one of them disconnect and another one connect but with with some delay
14:01 robotustra 12V,,contacts should keep like 10 A
14:02 maiden https://www.youtube.com/watch?v=ES-yKOYaXq0
14:02 robotustra I think usual car relay should work
14:04 robotustra sorry I'm a physicist, I'm not so into math humor :)
14:08 maiden aw, thats sad.
14:09 robotustra but I know what is fractal
14:09 maiden yet you are building robots ;)
14:09 maiden hehe
14:09 robotustra may be I'm too old for such humor
14:10 maiden you can newer be to old for the power of electrical humor, it got such potential, yet is often met with huge resistance.
14:11 botustra thinking how to commutate batteries for r
14:12 anonnumberanon haha
14:12 Snert_ seperate batteries for the motor.
14:12 anonnumberanon i must be 15
14:13 Snert_ or rather separate battery for the arduino since it won't use alot.
14:13 robotustra no, the idea is to have 2x12V batteries sequential, but charge them separately or in parellel
14:13 robotustra and track the voltage and current
14:14 Snert_ Maybe the robot can find it's own source of power and roll over and plug in to charge?
14:14 Snert_ like an IR beacon on the charger that it homes in on.
14:14 robotustra later yes, but while it has no brain yet I should charge it
14:15 robotustra I would prefer to charge it from tesla coil
14:15 robotustra wireless
14:15 anonnumberanon easy to do, look: https://www.youtube.com/watch?v=ut3sELMOyTM
14:15 robotustra but I'm not sure about electronics in it
14:17 robotustra :)
14:17 robotustra too stupid approach
14:20 robotustra maiden: how is the weather?
14:21 robotustra I see you use train? do not use cars?
14:28 maiden yes i do, but taking the car to work takes ~3h and parking costs ~10$/h while train takes me to work in 2h and i can work on the train. so its a no-brainer ;)
14:30 maiden the weather is a bit stormy and about 10C higher then usual
14:31 maiden so it was summer here in sweden last week (swedish meteorological definition of summer is when the temperature does not drop below 10C for 24h)
14:32 maiden its usually between 5 to -20 C this time of year
14:34 robotustra 2 hours?
14:34 robotustra to get to the work?
14:35 robotustra so every day you are loosing 4 hours to go to and from?
14:36 maiden nope, work from home 3-4 days a week and i am not loosing any time, because as i said, i can work on the train
14:36 robotustra ok
14:36 robotustra in here it's also warm for the decenber
14:36 robotustra in here it's also warm for the december
14:37 robotustra +5 today
14:37 robotustra should be around 0
15:29 Snert_ http://www.foxnews.com/tech/2015/09/02/laser-cannon-that-kills-drones.html
15:29 Snert_ off2lunch
20:32 akem i'm just lightning up an LED every second with millis() on arduino and for some reason its very unstable
20:33 orlock using sleep?
20:33 orlock and "unstable" how?
20:34 akem orlock no, just counting time with millis() then calling the function
20:34 akem timed event
20:35 orlock so getmillias() ?
20:35 orlock BlinkWithoutDelay style?
20:36 akem orlock unstable as visible to naked eye that the tick is not 1sec, feels like a code bottleneck but there is no other code running
20:36 orlock one second off, one second on?
20:37 robotust1a show the loop() code
20:37 akem orlock yea that sort of stuff, i quitted it for now
20:38 robotust1a akem: pastebin.com
20:38 robotust1a show me your code
20:39 akem robotust1a will try again tomorrow, if i still have the problem i might have missed something its late, will try my other board also.
20:40 robotust1a I inspected the blinking with oscilloscope on arduino board, and it's not stable, but not to such extent that you can see it with eyes
20:56 robotust1a becca
20:57 robotust1a who knows the current limit for Dupont connetion? 2.54mm?
20:57 robotust1a 2 Amps? 5 amps?
21:13 Hyratel robotust1a, well it's a two-leaf contact on a dupont female
21:13 Hyratel and dupont pins are ... close to 18 or 20 AWG in size
21:13 robotust1a I already told that it can handle 3Apms
21:15 robotust1a I plan to use at 1Amp max
22:06 rue_shop2 chinese amps are small
22:07 rue_shop2 3 chinese amps could easily only be 1.5 north american amps
22:07 robotust1a it will fit with my 1 canadian amp easy
22:09 rue_shop2 most probably