#robotics Logs

Aug 24 2015

00:00 xulf would also require building shore walls or frame as I go down which might be needed anyway
03:17 deshipu the nuts and bolts arrived \o/
03:18 deshipu nothing can stop me now
08:31 rue_school dont program it for what you want it to do, program it to not do what you dont want it to do
08:32 SpeedEvil I tried programming that way - and - well - atlantis.
08:34 rue_school well then you forgot to specify something didn't you
08:35 rue_school ok, I'm SO close on this absolte positioning code
08:35 rue_school // givens
08:35 rue_school A.x = 483.99; A.y = -65.57;
08:35 rue_school B.x = -8.34; B.y = 27.42;
08:35 rue_school C.x = 261.07; C.y = 287.29;
08:35 rue_school ARC = deg2rad(231.876);
08:35 rue_school BRC = deg2rad(105.835);
08:35 rue_school ARB = deg2rad(126.04);
08:35 rue_school
08:35 rue_school // statics
08:35 rue_school AC = dist2d(&A, &C);
08:35 rue_school CB = dist2d(&C, &B);
08:35 rue_school BA = dist2d(&B, &A);
08:35 rue_school ABC = deg2rad(inscribed (C, B, A));
08:35 rue_school BCA = deg2rad(inscribed (A, C, B));
08:35 rue_school CAB = deg2rad(inscribed (C, A, B)); // not used for this
08:35 rue_school
08:35 rue_school // calculations
08:35 rue_school M = (AC/BA) * (sin(ARB)/sin(ARC));
08:35 rue_school D = ABC - deg2rad(180) + BRC + BCA;
08:35 rue_school
08:35 rue_school ACR = atan( sin(D)/ (M+cos(D)) ); // should be 31.905
08:36 rue_school
08:36 rue_school printf("angle is : %f\n", rad2deg(ACR));
08:36 rue_school
08:36 rue_school I just need to make the numbers come out right
08:43 rue_school Angle ABC is 54.663259
08:43 rue_school Angle BCA is 78.315346
08:43 rue_school Angle CAB is 47.021396
08:43 rue_school angle ABC is being calculated wrong
08:44 rue_school no its not
08:49 veverak deshipu: pics
09:02 arty_knots is there any way to get data off a bluetooth smart hrm strap with almost no specs to a pc?
09:05 arty_knots i mean, would just a general usb bt4.0+edr+le adapter work?
09:54 NonSecwitter o/
09:58 deshipu veverak: pics?
09:58 veverak logicoma not done O_o
09:58 deshipu rue_school: pastebin
09:59 deshipu veverak: I'm have to work sometimes too
09:59 deshipu veverak: and I was away for the last week
09:59 deshipu I have*
09:59 veverak I see
09:59 veverak :)
09:59 deshipu also, I need to find some spacers
09:59 deshipu preferably transparent
10:00 deshipu maybe I will just cut a hose
10:05 blockh34d yay my project tango arrived
10:05 blockh34d anyone else tried one yet?
10:05 blockh34d now i just gotta figure out how to get the data off an android device and onto something i can actually work with
10:08 deshipu tango?
10:16 veverak fuuu
10:17 veverak my brain it hurtz
10:17 veverak ehmm, hwo to actually calculate
10:17 veverak how much alu. profile will increase it's length
10:17 veverak when in enviroment of +10C ?
12:27 Anniepoo veverak, as compared to what temp?
12:29 verak allready figured
12:30 veverak Anniepoo_eats: it's calculated against temp difference in simple form
12:30 veverak I supose I can use it in temp difference between 26C and 40C
12:30 Anniepoo_eats ok, that's 14 deg C
12:30 Anniepoo_eats now you need the coefficient of expansion of aluminum
12:31 Anniepoo_eats http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html
12:31 Anniepoo_eats 22.2e-6
12:32 Anniepoo_eats ah, you got it - yup
12:33 Anniepoo_eats I should learn to work with Caoutchouc just so I could say it a lot
12:33 deshipu I always thought that the expansion depends on the starting temperature too
12:38 Anniepoo_eats it does, but for most non metrology work it's not relevant, the constant is a reasonable approximation over
12:38 Anniepoo_eats sane temp ranges
12:38 Anniepoo_eats if this aluminum is going on an SR-71 more complex analysis is appropriate
12:39 veverak yeah
12:39 veverak that's what I figured out
12:39 veverak also even if it would double it's still in reasonable range
12:41 deshipu veverak: you wanted a pic: https://hackaday.io/project/7168-logicoma-kun/log/23997-hotglue-everything
12:42 veverak awesome!
12:42 veverak :D
12:47 mrdata i hotglued everything last week
12:47 mrdata including dropping it on my skin half a dozen times
12:47 mrdata causing small first and second degree burns
12:49 mrdata maybe next time i will try wearing gloves
13:14 deshipu what kind of hotglue is it?
13:14 deshipu I could never burn myself with it
13:14 deshipu it's just not hot enough
13:19 SpeedEvil There is 'warm melt' glue
13:19 SpeedEvil this melts at ~60C
13:19 mrdata try hotglueing things on fixtures above your head
13:19 SpeedEvil It's not really enough to burn badly
13:19 SpeedEvil then there is hot-melt which goes to ~100-120C and will burn you badly
13:21 mrdata the 60C stuff would not do for me, as these were flexible LED light strips that might get warm during use
13:23 deshipu time to program a 7seg display \o/
13:24 SpeedEvil One ah ah ah. Two ah ah ah. Three Segments ah ah ah
13:25 deshipu how do you call those displays that look like 7 segment, but also have the diagonals for letters?
13:25 deshipu 12 segment?
13:32 robopal hexadecimal i think
13:34 robopal no alphanumeric, doh
14:35 mrdata arent they 11 segments?
14:36 mrdata oh! 14-segment
14:36 mrdata https://en.wikipedia.org/wiki/Fourteen-segment_display
14:37 mrdata and in fact 16-segment is also a thing
14:38 mrdata deshipu, ^
14:39 deshipu fun
14:49 deshipu hmm, what could be the reason for the "." to not work, other than faulty display?
14:51 deshipu I guess they are faulty
14:54 mrdata sometimes there is no dot, except on the third unit from the right
14:55 deshipu well, I can see the dot physically
14:55 deshipu and it's supposed to be there according to the datasheet
14:56 deshipu but nothing lights up when i apply voltage to that pin
14:57 deshipu not that I *need* the dot, but it would be nice to know
14:57 deshipu oh well
15:04 deshipu ah, it's a clock display, doesn't have a period I guess
16:26 blockh34d hello i've been trying googles project tango
16:26 blockh34d my results are the resolution is not much better than a generation one kinect
16:26 blockh34d but the scan rate on my dev kit device is very impressive
16:26 blockh34d its motion tracking is good but not perfect it loses track of position and orientation a little too easily i think
16:27 blockh34d the 3d scan software i could find to test was an impressive start but limited severly by the accuracy of the motion tracker which seems like it still needs some work
16:28 blockh34d and i've gotten better scans out of skanect and a gen 1 kinect
16:28 blockh34d going to try out PCL on it soon maybe i can get something like kinfu widescale working
17:56 ace4016 anyone know what the hinge type is of those hinges that can hold some thing like a lid open just by moving the lid open? usually it holds the lid open in a wide range of angles...
18:21 mrdata ace4016, this type of hinge? or something else? http://howtodiy.de.vu/woodplanproject/wp-content/upload/2014/06/wood-work/hinged-top-coffee-table-plans-1.jpg
18:26 ace4016 something else; i think they're just called spring loaded hinges :P
18:27 ace4016 i just have to find the right type and weight load for my lid (assuming i go that route)
18:39 Snert_ spring loaded hinges.
18:40 Snert_ I've seen some where you can pre-load the hinges with the correct amount of tension for your load.
18:40 ace4016 sweet
18:41 ace4016 will make handling a 100 lb lid for a furnace/kiln easier
18:42 Snert_ I bet. But sounds like your use maight be pretty heavy. Dunno if they go that heavy on tension. If so, specialty shop.
18:42 Snert_ http://www.hardwaresource.com/hinges/door-hinges
18:42 Snert_ gate hinges are a good guess.
18:44 Snert_ if they dont have it I bet they'll know if it's possible.
18:45 ace4016 hrm...
23:09 copycat anybody knows a good book on motors/drivers/motion controller?
23:54 psYbR anyone have experience building robot arms? :)
23:54 psYbR I'm wondering about the suitability of 5:1 ratio geared NEMA17s for use in the construction of mine