#garfield Logs

Aug 19 2015

00:06 ^kat^ <chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat><chat>
00:07 rue_school I got it!
00:07 rue_school you give it 3 points and it finds the inscribed arc!
00:07 ^kat^ what will you do with it!?
00:07 ^kat^ oh
00:08 ^kat^ by which method?
00:08 rue_school well I was going to write a library for making gears, but I'm not going to now
00:08 rue_school first it forms 2 lines using the 3 points
00:08 rue_school then it finds the midpoints of those lines
00:08 ^kat^ but you need to make gears,, altho it canbe done mechanically, they did it before putes existed
00:08 rue_school then it rotates the lines 90 degrees aorund their midpoint
00:09 rue_school then it finds the intersection, thats the centre
00:09 rue_school then it finds the radius between the centre and one of the 3 points
00:09 rue_school I found that website and started making a new gear library using it
00:10 ^kat^ ah, the perpendicular line method
00:10 rue_school but I'm thrilled to have expanded my 2d library so much
00:10 rue_school damn, you mean I didn't invent that method?
00:10 ^kat^ explain to me how often you have needed to find the common radius of 3 points in your whole life
00:10 rue_school gee I wonder if I could use this library to implement my absolute positioning system
00:11 rue_school its not about my past, its about the future
00:11 rue_school now it wont be a problem
00:11 rue_school tho I should back it up
00:11 ^kat^ in what situation would it have been a problem in the future?
00:11 rue_school for making an absolute positioning system
00:12 rue_school do you remmeber...
00:12 ^kat^ ?
00:13 anx is flouder
00:13 rue_school http://ruemohr.org/~ircjunk/robots/abspos/code/problem.html
00:13 ^kat^ zhanx's spelling is off
00:13 zhanx i swear the code is if off
00:13 rue_school hah, I had it all the way down to a line intersection
00:13 rue_school and I had no intersection code
00:14 rue_school sh**
00:14 ^kat^ distance beacons : an ultrasonic chirp
00:14 zhanx also itd tuesday med nightt
00:15 rue_school THAT whole process is the answer to a problem with 3 phase circuits I was working on night before last
00:15 ^kat^ woman passed Ranger School
00:15 zhanx kat allowed to pass
00:15 ^kat^ robot locations solve 3phase circuits??
00:15 ^kat^ umm, ok, they allow ment o pass too
00:16 anx adds reminnder got 120v to220v project tomor
00:18 anx adds reminnder got 120v to220v project tomor
00:18 ^kat^ deja vu
00:18 zhanx mes suck
00:19 zhanx my motor functions are slwer
00:19 at^ draws lines all over the mon
00:21 zhanx i took the with Cesaren saolad
00:22 ^kat^ you mean with seezer salid?
00:28 zhanx kat i cheese out of the packet so yea
00:30 ^kat^ me 2
00:30 zhanx i get ten minutes to eat
00:31 zhanx ten minutes to have a idea
00:31 zhanx the rest is dragg t o bed
00:31 at^ is uploading pic for rue, amkes it all ea
00:31 zhanx i wants chocolate
00:33 ^kat^ only cows, 3MB for apencil sketch?!
00:34 zhanx ok
00:34 zhanx wow i hate that part of the pstd meds
00:34 rue_school yea, I can write the code for that
00:35 ^kat^ http://designerthinking.com/images/DSCF6704m.jpg
00:35 ^kat^ draw lines tween dots, at 1/2, draw 90 degree lines
00:36 ^kat^ circle radius is the meeting of the 3 lines
00:36 zhanx ok my micro wave is to become a 110sph-220sh covertr
00:36 ^kat^ zhanx, why is it to do that?
00:36 rue_school kat, it took a week of hard work to solve the point for the robot
00:36 rue_school it took 2 people proficient in math
00:37 ^kat^ really? took me 10 sec
00:37 zhanx kat bad purchase
00:37 rue_school you have to solve for the point the robot is at using the known positions of the 3 beacons
00:37 zhanx its a nice station wrong v
00:37 ^kat^ i gave you hints of 2 ways to do it last week
00:37 rue_school its already solved
00:38 rue_school ACR = atan(sin(D)/(M+cos(D)))
00:38 rue_school D = (L ABC - 180 + L BRC + L BCA )
00:38 rue_school M = (AC/AB) * (sin(L ARB)/sin(L ARC)
00:38 ^kat^ oh, there is a robot point too?
00:38 ^kat^ oops
00:38 zhanx do the transformer will fix tht
00:38 rue_school I can use the library I just wrote to do the math
00:38 rue_school but thanks kat :)
00:39 ^kat^ i think the math can be way simpler
00:39 rue_school not if you dont know the distances
00:39 rue_school all you know is where A, B, C are
00:39 rue_school and the angles from R to them
00:40 ^kat^ so 4 points, wait, what part didn't i solve?
00:41 rue_school http://ruemohr.org/%7Eircjunk/robots/abspos/code/robot.png
00:42 zhanx kat rue_school math
00:42 rue_school you have to find Rx,Ry
00:42 zhanx aka doing it for him
00:42 ^kat^ http://ruemohr.org/~ircjunk/robots/abspos/code/problem.html
00:42 rue_school all you know is where A, B, C are and the 3 angles from R to them
00:42 rue_school its already solved tho...
00:42 ^kat^ where is the robot?
00:42 zhanx rue_school, i will have time thursaday
00:43 zhanx cruch out some ideas\
00:43 rue_school the library I have expanded over the past 3 weeks can do all this stuff
00:43 zhanx these new meeds are strng
00:43 ^kat^ you wanna know whee the lines RA, RB, and RC are all identical? i did that
00:44 zhanx ok the whee lines got
00:47 ^kat^ http://designerthinking.com/images/DSCF6704m.jpg <<== the center of the circle, equidistant from all 3 points
00:47 ^kat^ i think if you look at it, you might find a way to not use 32bit trig functions
00:47 rue_school the robot might be at any place inbetween the 3 pillars
00:47 ^kat^ ok
00:47 ^kat^ did i understand the problem backwards?
00:48 ^kat^ you do not wat to know whee the distances are all equal?
00:48 zhanx ok goog night, sorry nre meds are strong
00:48 ^kat^ good dreams zhanx
00:49 zhanx if i have anyof them
00:52 ^kat^ rue, how do you know where the beacons are? x,y points, or angles off the robot's bow, or what?
00:52 rue_school the robot (R) might be at ANY point within the 3 beacons
00:53 ^kat^ ok, i drew that
00:54 ^kat^ are the beacons telling the robot their xy locatons?
00:54 rue_school but you fixed the robot in the middle of the tripod..?
00:54 ^kat^ this time i did not, i WAS solving a different problem
00:55 rue_school the robot know what beacon is at what angle
00:55 rue_school ah
00:55 ^kat^ so there is no known coordinate system for the beacons?
00:55 rue_school the x,y location of each beacon is known
00:55 ^kat^ brb, ggt, keep talking
00:56 rue_school the robot knows the angle around itself between each beacon
00:58 ^kat^ bak
00:58 ^kat^ but it does not know it's own xy ?
00:58 ^kat^ what a stupid root
00:58 ^kat^ robot
01:00 rue_school the spinning laser and the beacons are to find its location
01:00 ^kat^ how does it know the beacon xy?
01:01 rue_school the beacons are on concrete posts in the ground
01:01 ^kat^ ahhhhh
01:01 rue_school each has an identity and a defined location in a database
01:02 ^kat^ i presume 8bit accuracy is ok?
01:02 ^kat^ hmmm
01:03 ^kat^ so actually, the robot also doesn't know which post is which?
01:05 ^kat^ and the posts cannot chirp at the robot?
01:05 ^kat^ erg
01:05 rue_school I dont know what scale I'm working with yet
01:06 rue_school no ranging, just angles
01:06 ^kat^ k
01:06 ^kat^ then i need this for the boat too
01:07 rue_school supposedly boat people know how to do it, but I couldn't find their solution
01:07 ^kat^ pencil and paper on charts
01:07 ^kat^ usually 2 points, not 3
01:07 rue_school well, I'm done for the night
01:08 rue_school with 2 points, you can only work out your position to an arc
01:08 ^kat^ and this would be tons easierif the robot was not between all 3 at some time
01:08 ^kat^ if it was between 2 and found the 3rd
01:09 rue_school the plan was to have a field of beacons, the robot would pick 3 based on the best angles
01:09 ^kat^ o
01:09 rue_school I'll see if I can use the library I just wrote to solve for some positions
01:09 rue_school later
01:09 ^kat^ but it still would not know which was which
01:09 rue_school I have an exam on thursday and friday
01:10 rue_school tho it loooks like if I'm just CAREFULL, and READ THE QUESTIONS that I'll be ok
01:10 ^kat^ satalites do this to
01:10 rue_school expensive systems can do ranging
01:10 rue_school I cant
01:10 rue_school gnight.../
01:10 ^kat^ gnite
06:28 any12506350 ok rue, i found the robot without using trig, no sine, no cos, etc
08:27 rue_school ok
19:26 zhanx Kitchen Temp 86.54 *F Heat index: 96.40 *F
19:27 rue_school ERROR: UNKNOWN UNIT F
19:28 zhanx 30.20 *F
19:28 zhanx err C
19:28 rue_school 30c!?
19:28 rue_school ouch
19:29 zhanx low charge my compressor is frozen
19:32 zhanx that is coming from my ARM board, i got serial and the dht22 working today. would have saved an hour if my jumpers were right the first time
20:47 ^kat^ lets say the robot sees 135 degrees between two posts, if you graph all places where the robot can see those two posts at 135 degrees, the points form an arc between the posts
20:48 ^kat^ now, do the same for another pair of posts, you'll find the robot under the point of intersection of the arcs
20:51 rue_school hey, there you are
20:51 ^kat^ a more general way is to put the robot on a perpendicular line centered on the line between the two posts, draw lines from the robot to the two posts, then fit an arc into that triangle so it does NOT hit the robot, then you can count all the coordinates in that arc-sector as "no robot there"
20:52 ^kat^ .....put the robot on a perpendicular line where it can see the two posts at 135 degrees....
20:52 ^kat^ gotta include all the words
20:58 ^kat^ ...
20:59 rue_school yes, its an arc
20:59 rue_school yes, you have two arcs
21:00 rue_school a perpendicular line centered between the posts will almost never hit the robot tho
21:01 ^kat^ temp, for figuring where the "general arc" cold be drawn
21:01 rue_school hmm
21:02 ^kat^ the robot won't be on the perpendicular or on that general arc, but it does quickly eliminate a ton of space where the robot isn't to be found
21:02 rue_school :)
21:03 ^kat^ on the perpendicular, the perp forms two triangles,each with 90, 1/2 of 135, and 180 - (90+ (1/2 of 135)))
21:03 ^kat^ so you know with basic math where to put it to draw the elimination arc
21:04 ^kat^ you know the baseline, and the angles, so using cos math (not lookp tables even, you can get all the lines
21:05 ^kat^ if you wanted to
21:06 ^kat^ anyhoo, without looking up sin/cos/etc you can get close fast by knowing where the robot isn't
21:06 ^kat^ or use the first method i gave, and be super accurate
21:09 rue_school there must be a method of using geometry to do it
21:09 rue_school to directly pinpoint it
21:10 ^kat^ there is, i was trying to keep the work down to what a 8bit cpu can do
21:13 ^kat^ lets say you get the possible coordinates down to 65526 points in the yard, instead of solving complex math and multiple equations against each other, you could do binary guessing and get the answer in 5(average ?) steps
21:16 ^kat^ i dunno how much cpu you have to run on, how much time, etc etc etc
21:17 ^kat^ but anyhow, have fun
21:17 at^ ran a 16ft bead and at the end realised she didn't have on the welding jacket a
21:24 ^kat^ .....
21:24 rue_school those new 8 bit micros can do quite a lot you know
21:24 at^
21:24 ^kat^ which were you planning to use?
21:25 rue_school atmega32
21:25 rue_school or 328
21:25 ^kat^ k
21:25 rue_school 16mips can do a lot
21:25 at^
21:26 rue_school even an apple II could probably roll out the trig about 30samples/min or so
21:27 ^kat^ peeves me that the 20Mhz 65C02s still runs only 7mips
21:30 ^kat^ really, this is [insert year here], what have we got to do to get serious mips from a $2 24pin dip cpu?
21:33 rue_school well I dont need a supercomputer so I just stick to the 16 mips stuff
21:35 ^kat^ ok, but 20ns rams have been *very* cheap for years, and could be supporting a 50mips risc cpu
21:36 ^kat^ if there was a 100mips memory controller for small systems, mobo ram clocks stupidly fast, and could feed a multiprocessor running 800Mhz pulling 15w that fits in the palm of your hand
21:37 ^kat^ just saying there seems to be not much between avr and arm for hobby stuff
21:49 ^kat^ http://www.freescale.com/webapp/sps/site/taxonomy.jsp?code=HCS08
22:00 rue_school hmm
22:00 rue_school I dont like to get into lots of types of processors
22:05 at^
22:12 ^kat^ ok then, i go back outside to make more melty steel
22:41 Tom_itx http://www.activelight.co.za/
22:41 Tom_itx rue_school, that guy got several of em from me
22:42 Tom_itx 5 this last time
22:48 rue_school u?
22:48 rue_school hu?
23:02 any33428422 what�
23:04 Tom_itx programmers
23:05 any33428422 oh
23:13 any33428422 see, with a micro*processor*, you canhave it run an OS, and you just plugin a monitor and keybd and program it in your fav language
23:13 rue_school ah thats them
23:13 any33428422 ?�?
23:23 any33428422 .............................
23:25 rue_school sorry, test tommorow, I wrote a program that making example problems
23:25 rue_school and I'm working them out
23:26 rue_school Source: Delta
23:26 rue_school Load : Wye
23:26 rue_school Power Factor 0.961
23:26 rue_school Impedence 34.436
23:26 rue_school Source phase voltage 131.549
23:26 rue_school Source line voltage 131.549
23:26 rue_school Load phase voltage 75.950
23:26 rue_school Load line voltage 131.549
23:26 rue_school Load phase current 2.206
23:26 rue_school Load line current 2.206
23:26 rue_school Source phase current 1.273
23:26 rue_school Source line current 2.206
23:26 rue_school Total VA 502.529
23:26 rue_school Total W 482.969
23:26 rue_school Total VAR 138.839
23:26 rue_school in this one I'm giving myself the source voltage, the output wattage, and the power factor
23:31 rue_school wow, wtf
23:31 rue_school something isn't doing math properly
23:32 rue_school W = VA * PF
23:32 rue_school but my calculator drastically disagrees with the computer
23:33 any33428422 the puter may confuse PF with power and frequency ?
23:34 rue_school VA = VPl * IPl * 3.0;
23:34 rue_school W = VA * PF;
23:34 rue_school VAR = (W / PF) * sin(acos(PF));
23:34 rue_school no
23:53 any33428422 yanno, 32 feet of weld bead on steel that wa already tacked in place, looks like i didn't go anything
23:54 any33428422 erg
23:54 any33428422 tired
23:57 rue_school 32 feet?
23:58 rue_school isn't that 1/4" plate?