#robotics Logs

Jun 18 2013

00:55 MrCurious is this what it feels like being a suck-up in a soviet goulag?
03:23 Jak_o_Shadows did somebody here have a video of lots of servos being controlled?
03:31 RifRaf how many? i made a 7 dof arm with servos
03:32 Jak_o_Shadows Um, i'll do a count. 2 for the gun tilt/pan, 1 for the nerf gun fire (unfortunately it's not electrical), 1 for steering, and yeah, a robot arm
03:32 RifRaf http://www.youtube.com/watch?v=5VhbpxO4LIU
03:36 Jak_o_Shadows Hmm, my arm would be simpler than that. I just don't know what the msp430 is capable of in this regards
03:36 Jak_o_Shadows I had to patch the library, it was screwing around with analogWrite and servos
03:37 RifRaf you could probably use the same processing interface if you could get your msp430 to use the same commands
03:37 RifRaf is a great way to manage lots of servos when testing, and to create complex moves
03:38 Jak_o_Shadows Yeah, i was going to look into that
03:38 theBear analog write ? you err, don't use analog to drive (rc style) servos
03:38 Jak_o_Shadows I'm using a port of the arduino libraries, which is only skin deep
03:39 RifRaf ok well i was using webbotlibs for those servos, separate to the arduino libs
03:39 theBear efficient way to do lots is setup a timer to run roughly 2-3ms (i might be off by a thousand or so, been a long time) and just do a compare for each servo, flip the bit when you hit the compare
03:40 RifRaf theBear, did you find some fets?
03:40 theBear didnt' really look, tho actually i did come across a few, sore ass and non working leg kinda took precedence for the time being
03:41 RifRaf ok, well i'll dig up a few, sitting here drinking blood
03:42 theBear i hope yer mean alcaholic cordial
03:42 theBear meh, you can dig, but you aint gettin my address, not yet :)
03:44 RifRaf nah just had 2 more teeth ripped out
03:45 theBear bummer... i think i gotta do that soon, my front ones are getting all bended/crushed by the back ones
03:45 RifRaf feel like shit but is also nice not to have the ache i have been putting up with for more than a year
03:45 theBear yeah, that ache sucks balls
03:45 Jak_o_Shadows blood is fun
03:46 Jak_o_Shadows drinking it? not so much
03:46 theBear meh, i always liked the taste, and you gotta drink a lot to make you throw up... throwing it up without drinking it tho, much less fun
03:46 Jak_o_Shadows yeah, makes everything taste funny though
03:47 fRaf is not gonna eat for
03:47 Jak_o_Shadows don't let the holes get infected
03:47 RifRaf nope, they normally heal up well
03:49 joga blood pancakes are ok
03:49 RifRaf printing wheels now with hubs, will have new robots happening again soon
03:50 RifRaf nice and configurable ones http://www.thingiverse.com/thing:21486
03:51 theBear oh pretty, and funny title
03:52 RifRaf yep handy if you have encoders too, but these motors have them already so don't need it yet
03:54 Jak_o_Shadows would the spiral give you some suspension?
03:55 RifRaf yep, Triffid_Hunter showed me some he had made
03:55 Jak_o_Shadows cool
03:57 RifRaf the hub was not rendering correctly when i used the spirals so not using them just yet till i get change to look more at the code
07:11 GargantuaSauce GuShH i have a reprap and am suffering from dozens of issues with it and wanted to make something happen
07:13 GargantuaSauce Jak_o_Android: http://www.youtube.com/watch?v=1HPVbuaONO4
07:15 Jak_o_Android yeah, that
07:16 Jak_o_Android im happier throwi€g some logic chips at it ratger than messing around with another uC and talkimg to that somehow.
07:16 GargantuaSauce well those are just shift registers, the mcu is still doing the heavy lifting
07:17 theBear RifRaf, you mean physically or your software didn't like them ?
07:17 GargantuaSauce when i get back in august i think i am going to do another one with a cpld
07:18 Jak_o_Android lots of manual timing on the uC?
07:19 GargantuaSauce well just the end of each pulse
07:21 Jak_o_Android hmm, maybe i could that on a seperate chip, and talk to it. delays, such as counting the length of a sensor input, could start screwing it up?
07:21 GargantuaSauce well remember it only needs 2ms out of every 20
07:21 GargantuaSauce so you can do whatever else with that other 18
07:22 Tom_itx a little harder to keep track of in c than asm
07:23 GargantuaSauce oh yeah i forget people still use microcontrollers without decent peripherals
07:33 Jak_o_Android haha, well yeah. even worse, im using the arduino libraries on a non-arduino chip
07:33 GargantuaSauce yeah you really aren't doing yourself any favours there
07:34 Jak_o_Android if it disnt remove the toolchain hassle i probably wouldnt. getting my chip programming from my netbook is a pain
08:56 rue_more maybe you should use my bf firmware, then you just write your program to eeprom
11:36 GuShH RifRaf: what size tools can you accomodate on the toolholder they give you with the lathe? 3/8?
11:36 GuShH those are about the smallest they sell here
11:46 GuShH I guess half inch is about the maximum with the given toolpost, just an assumption. gotta determine whether I'll get a full set of 3/8 or 1/2
12:54 cuog GuShH: what lathe are you looking at?
13:48 GuShH cuog: hi
13:49 GuShH CQ6123/750 (9" X 29")
13:49 GuShH not sure if it's B series or not...
13:50 GuShH couldn't find the manual online but it seems all of these lathes come with a 1/2" toolpost from what I've seen.
14:04 cuog yeah you should have no problem using 1/2 in tools on that, may even handle up to 3/4
14:05 cuog I have a smaller 7" swing that was setup for 3/8 but I was able to maching down part of the topslide to lower the tool enough to use a 1/2 inch tool
14:52 RifRaf GuShH, i believe they are 1/2" tools, will check soon, is freezing outside still though
15:35 GuShH RifRaf: well in that case it's tempting to use 1/2 for many reasons, but smaller tools are also useful... hrmm.
15:36 GuShH these are the sets http://img2.mlstatic.com/juego-de-herramientas-de-torno-metal-duro-17piezas-cabo-38_MLA-O-86218583_4557.jpg
15:38 GuShH I'm not sure what 122 and 123 are for, as 163 and 1600 are the 60� threading tools (outside and inside)
18:00 buhman if I have some bodies position defined by x = t; y = sin(t); how can I 'convert' that into velocities of left and right wheels in a differential drive robot?
18:48 GuShH RifRaf: how cold is it outside?
18:48 GuShH 3�C minimum for today in Argentina
18:50 GuShH 8-13�C on sydney hmm so probably just as cold by the country side in AUS
18:50 GuShH nice and warm in the US...
19:50 RifRaf its about 13C now, was 0 this morning though
19:50 RifRaf i am up in the foothills away from the coast abit so gets chillier than at work where i am now
19:52 RifRaf nice frost this morning, just last week i thought winter would never get here
19:52 GuShH hmm black sabbath is going to play live here
19:52 ShH pokes the
19:54 GuShH RifRaf: I don't think winter has officially started here, but tomorrow we'll get 1�C or so and it's getting worse heh
19:54 GuShH heating is all fixed and operational, although I'm starting to think this furnace is too small...
19:54 GuShH but I can't afford a new one
19:55 GuShH they cost as much as a good used car.
19:59 GargantuaSauce time to get fold@home
20:01 RifRaf i use a gas heater i got from garage sale for $5, is awesome, and way cheaper than electricity
20:01 RifRaf GargantuaSauce yep, or a few more repraps
21:02 GuShH RifRaf: it's gas operated (natural gas) but the BTU rating falls short for all these radiators
21:02 GuShH not that I had any say on the design of this system... I just refurbished it so it would work
22:15 MrCurious i did it again. desk is full on covered in computers and robot guts. and that stupid overwhelmed feeling is back
22:23 GargantuaSauce if you ask me the former should never not be the case
23:12 rue_more oh, thats a good one, I took my socks and went to put them away in the trash bin
23:12 rue_more RifRaf, you printing yet?