#robotics Logs

Jan 15 2012

00:37 rue_shop :) heh
00:46 dunz0r rue_shop: How the heck did you get that many interrupt controllers, timers and dma controllers?
01:16 rue_house I fear to think that each of them came out of a 8088 pc I took apart
01:46 rue_shop I bet I can use the 8253 to generate pwm
01:46 rue_shop 2 channels
01:46 rue_shop hmmm
01:47 rue_shop but I bet I could get one of the 8042 to do the same thing
01:47 rue_shop but I'd need to run it external rom
01:47 rue_shop but no I have some eeprom 8042
01:47 rue_shop er eprom
01:47 rue_shop (uv)
01:48 rue_shop hmm
01:50 rue_shop I have 9 of them
01:51 rue_shop but without internal rom, I'm just the same using a z80 and family
01:51 rue_shop hmm using these is a challange indeed
01:51 rue_shop rue, you have eprom ones
01:51 rue_shop oh, right
01:52 rue_shop is it worth the trouble for only having 6?
01:52 rue_shop you said you wanted a pointless project
01:52 rue_shop that I did
01:52 rue_shop but I wanted to repurpose soemthing lieka cdrom board
01:52 rue_shop they are 8031
01:52 rue_shop mhm
10:39 Nashenas Hey guys, any idea how to find out if there's a general electronics store in my area that sells molex KK connectors?
13:14 rue_bed wow, I'z cleaning out circuit boards till like 4am yesterday
13:15 rue_bed lotsa stuff with parts I'll never use
13:15 rue_bed and a pile of parts off baords that only had a few things left to keep
14:04 rue_bed so, for the mowerbot, I think what I need is 2 direction controls, 2 pwm channels, 2 analog ports for working out the castor vector, and ... hmm not sure on caster rotation
14:04 rue_bed and I need inputs for bumpers
14:04 rue_bed 'bumpers'
14:04 rue_bed if I decide I do want it to yield to bumps
14:05 Steffanx So almost any controller will do
14:05 rue_bed it runs a pc
14:05 Steffanx Oj
14:05 rue_bed so I need a slave io interface
14:05 Steffanx *Oh
14:06 rue_bed my avr based general io card dosn't do pwm yet
14:07 rue_bed I have a 16 bit, 8 address bus off the pc
14:07 rue_bed (3 address lines)
14:09 Steffanx Oh you still use the good old interfaces of a pc :P
14:10 rue_bed non-software based io channels
14:10 rue_bed direct io
14:10 rue_bed real io
14:12 rue_bed not buffered, stacked, propigated, cached, pondered and then maybe acted on io
14:13 Steffanx Yeah, that sounds like the good old interfaces of a pc :)
14:15 rue_bed stupid serial
14:15 rue_bed one day their gonna just make the processors serial
14:16 rue_bed multi channel serial busses right out of hte processor
14:16 rue_bed intel will prolly have a few channel for each core
14:16 rue_bed silly 64 core machines
14:17 rue_bed 128/256
14:17 rue_bed threading on levels that defeat all optimization
14:19 rue_bed the north bridge will just become a path router
14:20 rue_bed as pcie channels route direct to a processor
14:20 rue_bed er core, hehe
14:20 rue_bed ok, rue, WAKE UP
14:20 rue_bed its not fair, I was up till 6:30am last night
14:20 Steffanx The thing is .. I DONT want to connect things I made to the CPU directly :P
14:21 rue_bed Steffanx, hah, even with my interface its not, I'm just talking to an ide controller
14:21 rue_bed just I'm in mode 0
14:21 rue_bed which happens to be isa
14:21 Steffanx Give me a USB interface and i'm happy
14:22 rue_bed see, if you want processing power on a robot you prolly just use an arm tho
14:22 rue_bed I refuse to do that
14:22 Steffanx Or a bare ARM.. ofcourse
14:23 rue_bed I jump straight from basic io controllers to full floating point computer
14:23 Steffanx Or a ARM with linux .. that's ok too
14:23 rue_bed x86
14:24 rue_bed its funny, io controllers started cause cpu's weren't fast enough to deal with things,
14:24 rue_bed now, io controllers are there so the cpu dosn't have to wait
14:27 Steffanx :)
16:13 KongfuPanda Steffanx, hello :)
16:19 Steffanx ?Hi
17:28 rue_house cool I think I can use a 8253 as a two channel pwm genorator
17:28 rue_house 16 bit!
17:32 rue_house hmm what freq do I want my motor pwm
17:32 rue_house 300 hz?
17:32 Steffanx 1khz
17:32 rue_house thats gets kinda noisy
17:34 rue_house shoudl I make it the note A?
17:35 rue_house 440hz?
17:35 Tom_itx C
17:35 Tom_itx 523.3
17:35 rue_house 523.251
17:36 rue_house how abotu the lower C
17:36 rue_house 261.626
17:37 e_house whats to know what came first, the definition of A at 440hz or the ability to measure
17:37 Tom_itx the latter
17:39 rue_house that means time was created around musical notes tho
17:45 rue_house I think B wins
17:45 rue_house for some reason I find A annoying
17:46 Steffanx Dont forget the Chords rue_house
17:47 rue_house I cant program the diffferent motors to different pwm freq's on this one, I have 3 timers, one is used as a reset rate genorator and the other two are monostables
17:47 Steffanx Ar
17:47 rue_house but I so want to do that on the 18 axis hexapod
17:47 Steffanx 18 axis :D
17:47 rue_house have it play music with the pwm timers as it moves
17:47 rue_house 'if you cant make it not make noise, make the noise nice'
17:48 rue_house Steffanx, have you seen buddy 3?
17:48 Steffanx Nop
17:48 rue_house !assist robots/buddy_III
17:48 rue_house !assist robots/buddy_III
17:48 tobbor Possibly http://eds.dyndns.org/~ircjunk/robots/buddy_III
17:49 rue_house http://eds.dyndns.org/~ircjunk/robots/buddy_III/p1020058.jpg
17:49 rue_house ok 247hz * 16636 ...
17:50 rue_house ABOUT 16mHZ
17:50 rue_house k
17:50 Steffanx I'll take a look at it tomorrow.. I REALLY should to go sleep
17:50 rue_house I dont think the 8253 can do that...
17:50 rue_house its ONE image!
17:50 rue_house http://eds.dyndns.org/~ircjunk/robots/buddy_III/p1020058.jpg
17:50 Steffanx Yes yes, but i want to see the other images too
17:51 rue_house see?
17:51 Steffanx :)
17:51 rue_house na, theri not interesting
17:51 Steffanx They are interesting enough for me
17:51 rue_house hmm the 8253 can supposadly get to 2.6Mhz...
17:51 rue_house so says this datasheet...
17:51 rue_house hmmmm
17:52 rue_house what I need is another datasheet
17:52 Steffanx You really use all the old *crap* you can find, dont you? :)
17:52 rue_house Steffanx, tell me a cheaper, smaller way to generate 2 pwm channels with a parallel interface?
17:53 Steffanx Cheaper..
17:53 rue_house 2.6Mhz is a stupid limit
17:53 rue_house Steffanx, thats right, its free, kinda limits the options dosn't it?
17:53 Steffanx Sort of
17:54 rue_house :( I'v yet to find a liquidated commercial project with reprogrammable avrs in it
17:54 Steffanx I don't say i don't like it.. i just wouldn't do it
17:54 rue_house its a 1 off project
17:55 rue_house at 2.5Mhz I could do 10 bit...
17:55 rue_house I suppose 10 bit is still overkill for motor speed on a mowerbot
17:55 rue_house I mean technically 5 bit would prolly work ok
17:56 rue_house ttl chips would come out larger
17:56 rue_house cant even expand to 3 ports without using more space than a 24 pin dip
17:57 rue_house that said I need a 2.5Mhz clock source
17:57 rue_house wonder what I have in oscillator modules
18:03 rue_shop cool I have a 2.45Mhz module I just stripped of soemthing last night
18:04 rue_shop hmm I souldn't be in my chop in my pajamas...
18:06 rue_shop ok, then I can use a 74373 for an generic output register
18:06 rue_shop then I need 2 channels of analog input....
18:06 rue_shop hmmm
18:08 rue_shop hmm by the time I use two dip20's for io, I wonder if I could just use a 6821
18:11 rue_shop I dont recall if the 8255 or the 6522 or the 6521 is a mroe attractive io chip
18:13 Tom_L bunny slippers too?
18:14 rue_shop I wonder what the 74ls783 is...
18:18 rue_shop na, get 3 io ports with a 8255
18:20 rue_shop oh its a mc6883
20:58 rue_shop new lesson about fire, air velocity, the higher the better
21:06 rue_shop ok I modified the draft fan power supply and fixed the rattle on the exhaust flap
21:33 L33TG33KG34R hey guys, has anyone here looked over the OpenServo project?
21:39 Tom_itx i think it's been around a while
21:41 L33TG33KG34R well I was wondering if they were worth looking into
21:42 rue_house its a good project
21:42 rue_house we have worked iwth it a bit
21:43 L33TG33KG34R well I need fast and accurate servos for a pan/tilt/roll gimbal. Its stabilized so thats the reason for the fast and accurate response
21:44 Triffid_Hunter hobby servos won't cut it?
21:44 rue_house ok
21:45 L33TG33KG34R no no... Hobby servos can cut it, but they are super expensive... ~$100 a pop
21:46 Triffid_Hunter L33TG33KG34R: ah, what do you need from them that requires $100 servos?
21:46 Triffid_Hunter L33TG33KG34R: because if it's just lack of dead zone and little to no overshoot, get a standard hobby servo and stick an atmega in it or something, reuse the mechanics and motor
21:47 Triffid_Hunter then do your own PID and whatnot
21:47 L33TG33KG34R fast response but with smooth motion and accurate positioning (I hope you understand what I mean)...
21:47 L33TG33KG34R that would involve recreating what OpenServo aims to do
21:47 Triffid_Hunter L33TG33KG34R: yeah you want it to get to the target quickly and hold without overshooting, and with good precision
21:48 L33TG33KG34R yeah
21:49 L33TG33KG34R http://www.servocity.com/html/servoblocks.html I was thinking of building my pan/tilt/roll setup using three of these...
21:50 Triffid_Hunter L33TG33KG34R: woah, $25/ea and I just made something fairly similar on my reprap just the other day
21:51 L33TG33KG34R well, I don't have a choice since I need something pretty quick in the next 3 weeks...
21:52 L33TG33KG34R and they seem well built to handle a bit of abuse... the pan/tilt/roll gimbal is going to be mounted on an RC car, the HPI Savage FLUX to be precise... a beastly little car.
21:54 L33TG33KG34R but thats without servos, I am still stuck with the problem of which servo.
21:56 Triffid_Hunter L33TG33KG34R: MG996R perhaps.. dealxtreme have 'em for $14, been keeping an eye on them
21:57 L33TG33KG34R http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6221
21:57 L33TG33KG34R $10
21:58 Triffid_Hunter nice
22:03 Triffid_Hunter L33TG33KG34R: fwiw, having a reprap for this stuff is awesome, see my latest vids at http://youtube.com/triffid0hunter
22:03 Triffid_Hunter I've printed the ankle but haven't taken any vids yet because I needed to adjust stuff in the model and haven't printed new ones yet
22:05 rue_house I have to put a 3d printer on my todo list
22:05 L33TG33KG34R agreed, a reprap or the like would be nice but no budget for one... :(
22:06 rue_house heh
22:06 rue_house bets I make mine within a $20 budget
22:07 L33TG33KG34R http://blog.ultimaker.com/ seems like a good contender... but I would just order off Ponoko
22:10 L33TG33KG34R Why is it that futaba servos are more expensive than Hitecs for similar specs?
22:10 rue_house brand
22:11 L33TG33KG34R wow, and their plugs are also non standard...
22:12 rue_house you looking at the digital ones?
22:12 L33TG33KG34R yeah
22:12 rue_house all digital servos are really expensive
22:12 rue_house the std analog ones are cheap
22:12 L33TG33KG34R well $30 for a digital servo isn't too bad in my opinion
22:13 L33TG33KG34R http://www.servocity.com/html/hitec_servos.html
22:13 rue_house thats prolly not digital
22:13 rue_house they all takes pulses, but the digital ones hold the motor betwen pulses and do PID control
22:13 rue_house the digital ones can also have a terminal plugged into them to reprogram their paramiter tables
22:15 L33TG33KG34R that was one of the reasons I was looking at OpenServo. Its open standard for programming is really helpful but without the correct hardware its almost useless.
22:15 rue_house heh, yes/no
22:15 L33TG33KG34R almost...
22:15 rue_house http://eds.dyndns.org/~ircjunk/robots/buddy_III/p1020058.jpg
22:15 Kimlaroux http://blog.ultimaker.com/wp-content/uploads/2011/10/4.jpg wow this transparent 3d printer looks nice
22:15 rue_house those are all avr based servos
22:16 L33TG33KG34R what is that?
22:16 rue_house interesting, a school where you have to make a reprap
22:16 rue_house thats my hexapod
22:16 L33TG33KG34R ah...
22:16 rue_house my next step is the overload control boards
22:22 L33TG33KG34R the .xx sec rating is for going 60 deg?
23:19 L33TG33KG34R http://www.servocity.com/html/hs-5485hb_servo.html