#robotics Logs

Apr 02 2013

01:45 RifRaf rue_bed, wanna make a robot?
01:53 rue_bed not now rif, its 11:30pm and I have to go to work in the morning
01:53 RifRaf ah come on
01:55 rue_bed I have a 48V wifi robot in the shop I need to get working tho
01:55 RifRaf well let me plant a seed anyway, lets make a communial bot, where we all end up with one
01:55 RifRaf share talents and ides, and then make the distributed army of robots do something cool together
01:56 RifRaf like take over the world
01:57 RifRaf anyway, anyone interested lets talk about it
01:57 SunStar ardupirates might be interested
01:59 SunStar i am but i have nothing i can offer atm
02:01 RifRaf hi sunstar, where you from?
02:01 SunStar california
02:03 RifRaf cool, well i bet you have some skills, or at least want to get some if you are in a robotics channel
02:04 SunStar yeah i build these: http://undivide.no-ip.org/
02:06 RifRaf what part? making computers or websites?
02:06 RifRaf or cpus, there was alot on there to make\
02:06 SunStar lol oops
02:06 SunStar wrong paste
02:06 RifRaf heh
02:07 SunStar any way yeah thats all mine. i ment to link the UAV but i also make retail kiosks, point of sale systems and engine tuning computers like ud see in those fast n furious movies
02:08 SunStar im working on a submersible drone for underwater filming atm
02:10 RifRaf all cool stuff, so you have lots of skills but no spare time
02:11 SunStar no i have time just no money
02:14 RifRaf well am just throwing the idea out at the moment, we tried once before
02:17 RifRaf never got off the ground,but no harm in trying again
02:19 RifRaf but a little robot with a bunch of little robot friends around the world would be cool
02:25 fRaf replaces the bucket lid wheels with nice red and black
02:25 RifRaf gone larger again to try get more stability
02:35 Hukka So, what would the little robot do?
02:39 RifRaf Hukka, thats open for discussion, have some ideas but have not hit on the great idea yet, am sure there is something not too complex and cool we could do
02:39 RifRaf but with many heads it would allow greater complexity that we could do alone, thats the idea
02:40 Hukka So, the idea is to crowdsource the design, and then everyone would built it on their own?
02:40 Jak_o_Shadows crowdscource software
02:40 RifRaf and i bet there is some great ideas that could be done with a robot cluster
02:41 RifRaf nope, just get a fedw keen people, as for the actual biuld thats where alot of people just cannot do it
02:42 RifRaf and i would be happy to share all the offcuts of cool material i have access to, including the cnc stuff, so people without tools and cnc etc can still get parts
02:43 Jak_o_Shadows but like RifRaf, you're in another state...
02:43 RifRaf its a small world these days, ans shipping stuff does not worry me
03:31 RifRaf http://imagebin.org/252502
03:31 RifRaf thats motors and drivers for next balancing bot, will i or should i have encoders on the wheels?
03:33 RifRaf hoping to use accel to keep it level and sence slope with ultrasonic
03:33 RifRaf and want it to be able to move around and avoid stuff with a few more sensors up top
03:36 RifRaf was hoping the accel and gyro could take the place of encoders
03:58 Jak_o_Android Anyone had any experience with the Tc4420 midget driver.
04:01 Jak_o_Android Mosfet. Damn you autocorrect.
04:04 RifRaf lol
04:05 RifRaf Jak_o_Android, nope, do you have some?
04:06 RifRaf i found a bunch of smd 4081's if you want a couple
04:06 Jak_o_Android No, but a local supplier has, which beats eBay hopefully.
04:08 Jak_o_Android Haha, smd.
04:08 RifRaf why don't you just get what Triffid and i both think is great fro a fet driver
04:08 RifRaf then you can get help easy etc
04:09 Jak_o_Android Hmm, I should get some protoboard
04:09 RifRaf wlel i have dip as well but not as many
04:09 Jak_o_Android Yeah, that's likely what I'll do.
04:10 RifRaf did you see the drivers in the pic i posted before, well thats the easy way
04:11 RifRaf theyare good to 20 A and seen place seel them good for 50A
04:12 Jak_o_Android Immature, might have lost it when I switched go Android, do you mind reposting?
04:12 RifRaf man i bet alot of people would think i was not english the way i type
04:12 RifRaf http://imagebin.org/252502
04:13 Jak_o_Android I might
04:13 RifRaf they have mega big heatsink going through to other side
04:14 Jak_o_Android Yeah, I haven't got my heatsinks yet.
04:14 RifRaf i only want to drive them for those 2A motors, so will be 5A max i reckon
04:14 Jak_o_Android Yeah, don't go too much.
04:15 Jak_o_Android Also cool build
04:15 RifRaf cause this balancing stuff seems to put alot of pressure on motors
04:16 Jak_o_Android Yeah, I can imagine it would. Would have the peak current quite often I would think.
04:16 RifRaf is nice being able to cut your drunk ideas out in lunch break
04:16 RifRaf yep did you see what i did to the first servo?
04:17 RifRaf and done 3 servo horns so far
04:17 Jak_o_Android Continuous mod it?
04:17 RifRaf yeah
04:17 RifRaf only take a few minutes each with these, so remade another quick
04:17 SunStar jameco.com
04:18 Jak_o_Android I actually don't have any servos, might need some.
04:18 Jak_o_Android May be able to get computer vision working.
04:18 RifRaf http://imagebin.org/252316
04:18 RifRaf get spares :)
04:19 RifRaf thats a fet without decent heatsink
04:19 Jak_o_Android Lol
04:20 Jak_o_Android I might fan cool my fets
04:21 RifRaf you'll be fine if you overbiuld it a few times
04:21 RifRaf heatsink should be enough unless you are driving them really hard
04:22 Jak_o_Android Alternate cooling: make it go really fast, to air cool the gets.
04:23 RifRaf fast is good, just make sure you can stop
04:24 Jak_o_Android Lol, course it will be able to stop. Failure is always an option.
04:24 RifRaf i need some rubber to wrap around these wheels, maybe a window glass sealer
04:24 RifRaf has to stay on a 4mm wheel
04:25 RifRaf i need to invent the tire, lol
04:26 RifRaf at least i don't try and reinvent wheels though
05:19 RifRaf Jak_o_Shadows, i found a bunch of tc4422 and tc4468/9
05:22 RifRaf you should be able to sample em from mc same as i musta
05:23 Jak_o_Shadows yay for samples
05:24 RifRaf back when i musta been trying to make me own motor driver, you can have some if you like, but the 4081/2 will be better
05:26 Jak_o_Shadows intersil has free samples. I kinda want dip though, and I don't know what sample is dip
07:06 BlueMint Hi, I'm looking to make a hexipod or spider robot. Where is a guide that can teach me how to do this for cheap?
07:34 mrliao cheap... is how cheap?
08:52 Skwint so cheap that he doesn't waste bandwidth answering that :p
08:53 theBear hi kitty :)
09:42 hackkitten hi theBear :D
09:42 ckkitten huggles her bear ^
12:20 MrCurious RifRaf: how many feet did it get before this happened http://imagebin.org/252316
13:48 GuShH MrCurious: overdriven obviously...
13:48 GuShH thermal runaway is something that happens to every arduinian.
13:48 ShH
13:51 MrCurious going for the feet fet word play. i shot... i missed...
14:01 RifRaf MrCurious, was just moving on the spot trying to balance, alot of jitter caused it
14:02 RifRaf and wore out 3 servos horn, but am getting there now, alot more stable
14:02 MrCurious how did you solve the thermal meltdown? heat sink, or some kind of pucking (embedding in epoxy)
14:02 RifRaf nope, just improved the PID settings
14:02 RifRaf and bigger wheels
14:03 RifRaf http://imagebin.org/252503
14:04 MrCurious looks very cool. why are the batteries in the one on the right looking dark and worn?
14:05 MrCurious did they flame out
14:05 RifRaf they are about 8 years old
14:06 RifRaf used in rc car racing ages ago
14:10 RifRaf MrCurious, the mg996 servos are not bad, but also not perfect, they seem to have a very small dead zone, so jitter is hard to avoid
14:10 MrCurious hmmm
14:11 MrCurious doing it with the gear motors was a no go?
14:11 RifRaf and the ultrasonic sensor is not the fastest, but did work for the test, going to try a gyro etc in next one
14:11 RifRaf gearmotors is the new version
14:11 MrCurious oh! cool
14:11 RifRaf they are 200rpm, so should work alot better than the 60rpm servos
14:11 RifRaf and 2A each, with 20A plus drivers, should be no burning out
14:11 MrCurious should. i bet they have some monster torque :)
14:12 RifRaf yep, i cannot stop them by hand, or even slow em down
14:14 RifRaf want to use 4 ultrasonic for object avoidance, 2 more for slope detections, and gyro/accel for balance
14:15 MrCurious my ultrasonic array is 10 sensors, 36 deg seperation, sr-04's
14:15 RifRaf yep using same ones
14:15 RifRaf you have any pictures or video of what you are making with them?
14:16 MrCurious no, my house is a mess. too embarassed to photo inside. maybe tonight i will do some driveway shots
14:17 RifRaf cool
14:32 GuShH MrCurious: why is your house a mess?
14:46 Hukka I wonder if this will fulfill it's promises http://www.kickstarter.com/projects/codelabs/duo-the-worlds-first-diy-3d-sensor
14:46 MrCurious i have a cat problem
18:30 Rif a motor driver requires a left and right pwm signal and an enable line
18:31 dunz0r Rif: Not necessarly. Depends on what driver it is.
18:31 Rif however it appears to work by putting pwm on the enable line and and using logic for the left and right pwm to control direction
18:31 dunz0r If it's an H-bridge type driver. Like an L293 or L298, that is correct.
18:32 dunz0r The left/right turns the a side vs the b side.
18:32 Rif yep cool, makes it easier to get going then
19:41 orlok always remember - no nut is too big if you have a vice and a mallet!
20:34 GuShH orlok: also, no nut is too big for paris hilton.
21:04 MrCurious you cant just drive a motor driver with a L pwm and R pwm tie enable to on
21:05 MrCurious or use PWM for enable, and digital for L, R
21:15 Rif am sure i have though, will wire up again and try same code that was workingt before moving on
22:25 Tom_itx MrCurious with LAP pwm you can but it's not so efficient
22:26 MrCurious ok
22:27 Tom_itx where 50% duty is stop
22:30 MrCurious doesnt sound it
22:30 MrCurious i need to find a better method of tapping holes in AL. my wrists are shot from manually tapping 8 holes
22:31 Rif this is the data i can find about the drivers in question http://arduino.cc/forum/index.php?PHPSESSID=1cdde738cffd12d0caabb88fd4bbf831&topic=111000.msg835021#msg835021
23:27 Rif is gonna be handy having voltage and current outputs for the adc on the motor driver