#robotics Logs

Jul 30 2015

01:19 rue_house mroe output current
01:24 wolfmanjm rue_house: sorry which one is better?
01:25 rue_house the ne one
01:25 rue_house new
01:53 wolfmanjm oh so the non-LM2596 are better?
01:53 wolfmanjm have you used them?
01:53 wolfmanjm looking at the specs they both say they will need heatsinks over 2amps
02:01 deshipu well, otherwise they would need to deal with physics police ;)
02:02 deshipu for breaking the law
02:02 deshipu of physics
02:18 wolfmanjm not really the PCB is meant to be the heatsink for the LM2596, the other one is too small for that
02:19 wolfmanjm that is if the PCB is laid our correctly and has enough copper under the chip
02:22 deshipu as if
02:22 deshipu that board doesn't have enough copper to cool a LED
02:26 just_pink hi
02:27 deshipu hello just_pink
02:28 just_pink hi deshipu , this is my first time here.
02:29 deshipu welcome
02:29 just_pink you know how I can power 24V led from 5v?
02:30 deshipu you can get 24V from 5V using a boost converter
02:30 deshipu but are you sure the LED is actually 24V?
02:31 just_pink yes, It say AC DC 24V
02:31 deshipu AC?
02:31 deshipu are you sure it's a LED?
02:31 just_pink and thay connect in series with dide bridge,
02:32 just_pink deshipu: it's a stack light
02:33 just_pink deshipu: I can modify it by re desigen the pcb, but I'm prefer not to do it.
02:33 deshipu it probably has much more inside than just a LED
02:33 deshipu you could probably change the voltage just by replacing the resistor on it
02:34 just_pink deshipu: just several LEDs in serias
02:35 deshipu oh well, then boost converter it is, I guess
02:36 just_pink like joule thief?
02:38 just_pink deshipu: ?
02:38 deshipu http://www.aliexpress.com/item/Wholesale-1pcs-DC-DC-step-up-converter-boost-2A-power-supply-module-IN-2V-24V-to/32284454431.html
02:38 deshipu something like this
02:38 deshipu not sure what amperage you need
02:42 just_pink wow 3AM..
02:43 just_pink I'm going to sleeep.
03:05 rue_bed the reprap is printing me a sumobot wheel, I can sleep now too
03:05 rue_bed tommorow I head into vancouver for a laptop of some sort
15:14 deshipu hmm, how would I do the inverse of inverse kinematics?
15:14 deshipu basically, I have a 3-joint leg, and I know the forces applied at each of the joints
15:14 deshipu and I need to calculate overall force acting on the tip of the leg
15:15 deshipu the direction and magnitude
15:18 wolfmanjm is that forward kinematics?
15:19 wolfmanjm probably not :) but inverse of IK would be FK
15:26 deshipu there can be more than one inverse :)
15:36 deshipu ok, I think I got it
16:08 veverak deshipu: that doesn't sound complicated
16:08 veverak so, am I missing something ? or it is really easy?
16:09 deshipu well, it's easy if all joints are othogonal
16:09 deshipu bu they are not
16:09 deshipu two of them have parallel axes
16:09 veverak well yeah
16:09 veverak but you should be able to get vector that tells you it's "poweR"
16:09 veverak or, "force" tehre is
16:10 veverak and just join the vectors?
16:10 deshipu all I have is two torques
16:10 veverak I mean, force compared to the base of leg, which is all that is complicated to make :)
16:11 deshipu soo, the first servo reads '10' and the second reads '20', how do I get a vector out of that?
16:11 veverak I see
16:11 veverak now I get the hard part :)
16:11 deshipu but I think I figured it out
16:12 deshipu calculate the force vector separately for each of the joints, assuming the other joints are fixed and can't move
16:12 deshipu then add the vectors
16:12 veverak yeah
16:12 veverak well
16:12 veverak is it just me that usually finds "vectors" very easy to work with?
16:13 veverak so I tend to make what is possible into vectors
20:38 just_pink someone know where I can find white acrylic sheet?
20:38 orlock It would depend on your location?
20:38 zhanx and size
20:38 zhanx mcmastercarr state side
20:38 zhanx orlock how goes the fight
20:39 zhanx wife took the kids and gave me a few hours off
20:39 orlock Eurgh
20:39 zhanx and a case of beer
20:39 zhanx i feel loved
20:39 orlock ahh nice
20:39 orlock we had a power outage from 8am-3pm yesterday
20:39 orlock scheduled
20:39 zhanx i didn't say not my beer, its cold
20:40 orlock after it, my problematic EoP link started working
20:40 zhanx hated those, i always forget them
20:40 orlock and then stopped again
20:40 orlock grrrr
20:40 zhanx kick it
20:40 orlock EoP worked from spare room to shed perfectly
20:40 orlock moved PC out of spare room
20:40 orlock EoP doesnt work from kitchen to shed
20:40 zhanx orlock, by chance you know of a stm32 simulator?
20:40 zhanx too far?
20:40 orlock but after outage it did work, for a bit. now doesnt
20:41 orlock doubt it, probably a fuse/noise/capacitance type issue rather than pure distance
20:41 zhanx over 385 feet ( you convert that)
20:41 orlock yeah, less than that
20:42 zhanx i would ohm the wires
20:42 zhanx yea i know pita
20:42 orlock it doesnt work from kitchen to spare room either, so its a "different leg" problem rather than pure distance
20:42 zhanx k
20:42 orlock this is EoP
20:42 orlock not PoE
20:42 orlock by the way
20:42 orlock :)
20:42 zhanx i got that
20:42 orlock i'll see if i can plug them all in on one powerboard
20:42 orlock and get up the management tool
20:42 orlock drop the rates down
20:43 orlock Corp. IT security are being a bit useless
20:43 orlock watched Mr Robot?
20:44 zhanx nope and dont ruin it
20:44 orlock in general or at all?
20:44 zhanx at all
20:44 orlock i mean, have you watched it at all, or just not the latest?
20:44 zhanx waiting for it on netflix
20:45 orlock ahh, you think it will end up there?
20:45 zhanx yes i got an email on it
20:45 orlock ahh, we are stuck with the australian netflix
20:45 orlock damn
20:46 zhanx i plan to bing watch thanks
20:46 orlock apparently they have some ads as a pisstake
20:46 orlock so i oonly heard about that due to reading discussions
20:47 zhanx not here
20:47 zhanx voted down hard
20:47 orlock as in fake ads with real ads during the show, as a mindfuck
20:49 zhanx orlock, dont make me come over there, and break a leg
20:50 zhanx you know can and would
20:50 orlock heh
20:50 orlock What was the HaD prize for?
20:51 zhanx best user interface
20:51 zhanx i put in work
20:51 zhanx touch screen outlet and room controls
20:51 orlock ahh yeah i saw that
20:52 zhanx 2 weeks of epic programing
20:52 orlock i have one major bug left in my code
20:52 zhanx i can create or destroy a user interface any where on the screen
20:53 orlock nice
20:53 zhanx and the touch system moves with it
20:53 zhanx sucked
20:53 zhanx but i won stuff
20:53 zhanx still in the running
20:54 zhanx switching to arm, keeping 90% of the code and making it faster
20:54 zhanx when i am done you will want this in your home