#robotics Logs

Jun 11 2013

00:13 rue_more for cutting?
00:19 MrCurious i see. being a programmer is to have a love of having the feeling of being brilliant and being a moron alternate rapidly....
00:24 rue_more hah, good point
00:33 MrCurious it seems i am currently on the less desirable phase
00:36 rue_more how so
00:37 MrCurious chasing the same bug for 1.5 weeks now
00:38 MrCurious when i run the full test suite, it appears
00:38 rue_more whats the bug
00:38 MrCurious when i run the test suite 1 test at a time, they all pass
00:39 rue_more ok, gnight
00:39 MrCurious and the test suite takes 3 hours to run
00:39 MrCurious down from 8+ hours
01:21 MrCurious anyone see WWDC today?
01:22 MrCurious will PRISM run on the iphone as a native application?
01:33 orlok Fluke 45 bench multimeter
06:13 theBear wow ! that megamind movie is emotional and heartwarming !
07:43 knob Hello all
07:43 Jak_o_Shadows hi
07:44 knob Jak_o_Shadows, any robotics forums you can suggest?
07:44 knob I'm starting out in this field/hobby/interest
07:47 Jak_o_Shadows umm, I dunno. I plan on posting on my relevant uC major forum (with is 430h for msp430), but maybe r/robotics?
07:48 knob ok ok thanks
07:48 knob I checked /r/robotics... yet, although /r/ is cool... somehow, typical forums are (for me) better
07:48 Jak_o_Shadows yeah. What uC are you using?
07:50 knob uC?
07:54 Jak_o_Shadows micro-controller
07:55 knob Oh! Just starting, so still don't know the terms. =)
07:55 knob Well
07:56 knob at the moment, I don't have much...
07:56 knob I have two Arduino Unos, and one Raspberry Pi
07:56 Jak_o_Shadows I don't how common that term is, i just dislike writing micro-controller all the time
07:56 Jak_o_Shadows that's decent
07:56 Jak_o_Shadows I think the RPi is generally too power hungry to use on a robot, but it's definitley still useful
08:00 knob Well, first project I want is to create a small frame, for a lawnmower
08:01 knob so, looking for a relay board or something, and then some motors
08:01 knob for motors, not sure if to buy from eBay those mobility scooter motors, or... what
08:01 knob Yet, eager
08:04 Jak_o_Shadows Yeah, power control is going to be hard.
08:18 knob Jak_o_Shadows, do you think with DC relays, it will work?
08:18 knob Although... wait... thinking about that... DC relays are an on/off affair
08:18 knob I'm looking for 0-100% power. What would that be called? PWM?
08:22 Triffid_Hunter knob: yep. simplest arrangement is a mosfet and a relay. preferred arrangement is a h-bridge.
08:23 knob h-bridge? Googling that now
08:23 knob =)
08:23 Triffid_Hunter knob: https://picasaweb.google.com/lh/photo/TYZEKttEzL-Gs6jMMpW0rNMTjNZETYmyPJy0liipFm0 <-- there's one I made recently, solid up to 15A by design, should go higher
08:24 Triffid_Hunter knob: the square chip to the left is the same silicon as an arduino and can be treated as one if you're feeling masochistic
08:24 knob Nice! Headed over there now
08:27 Triffid_Hunter I ran that R/C car with it until the gearbox stripped out, then a friend sent me a rolling chassis with a crazy motor which I had up to maybe 60km/h with that ESC, kept melting the sense resistor though.. got a bigger one on the way
08:27 Triffid_Hunter mosfets didn't die, which is the most common h-bridge failure though :)
08:29 Triffid_Hunter and when you have two parallel lengths of solid core network cable where the insulation carbonised then the wires fused together then broke, you know the battery was pushing electrons quite hard that day...
08:29 GargantuaSauce not particularly hard, but lots of them!
08:31 Triffid_Hunter knob: http://triffid-hunter.no-ip.info/esc_sch.png http://triffid-hunter.no-ip.info/esc_brd.png
08:42 knob CHecking now!
08:43 knob Sorry for the delays... @ work =)
09:12 rue_more knob, for driving a motor?
10:04 knob rue_more, yes!
10:04 knob Any thoughts?
10:28 knob Hey guys, n00b question: Is this item in eBay able to control the speed of a motor? Or is it just on/off ? http://www.ebay.com/itm/1xArduino-Smart-Car-50A-Dual-Motor-driver-module-high-power-Hbridge-strong-brake-/261004097423?pt=LH_DefaultDomain_0&hash=item3cc50e778f
10:43 GuShH rue_more: no, flame rods are for fire detection (used on water heaters, furnaces, etc) it's basically flame rectification
10:44 GuShH AC is picked up by the flame and rectified by the rod, then the few uAs across it are used to determine whether there's flame or not
10:44 GuShH in theory the rod is or acts like a diode
10:45 GuShH so if that dc current has a low offset the furnace may think there's no fire (even if there is) and shut down
10:45 GuShH everyone says "clean the rods" (that would lower the overall circuit impedance) but I'm still seeing problems, might have to replace it
10:45 GuShH not expensive, just can't find them everywhere.
10:46 GuShH getting 3.7uA max upon startup
10:47 GuShH not sure what the typical value is for this setup, often 4 to 6 they say
10:53 GuShH so I either have it positioned wrong (I took it out to clean it and installed it as-was) or there's a ground fault somewhere
10:59 GuShH LAWL at HVAC multimeters... what a bunch of wankers
18:15 GuShH ahh where's rif :(
18:18 theBear erm, probly just starting work at 9am
18:19 ace4016 and why aren't you starting work at 9am mister? :P
18:19 theBear i don't "do" work <grin>
18:19 ace4016 lol
18:25 GuShH theBear: work "does" you?
18:25 GuShH ahh heating back on, finally.
18:25 ShH wipes nose on theBear's s
18:32 theBear hehe, yep, that's why they call me a "pro"
19:27 MrCurious wonder if this is one of those great times to invest in turkish stocks
19:29 MrCurious if you fight a bug for 2 weeks... when you kill it it turns into pizza
23:24 MrCurious as i watch this turkey conflict, i cant help but think that if the protestors media peolpe had plantable secure web cams... they could monitor a area they give up thats likely to ge used by the enemy
23:24 MrCurious would make for a hell of a story
23:25 MrCurious i think the news media in general needs to get good with a concept called a disposable camera
23:32 cuog MrCurious: a friend of mine going to school right now for film and media wants to do just that