#robotics Logs

Aug 22 2014

00:32 rue_bed hmm
00:32 rue_bed I got the sideshow working!
00:37 rue_bed lets try it!
00:38 rue_bed http://ruemohr.org/~ircjunk/robots/arm8/slide.htm
00:38 rue_bed I think it works!
00:41 rue_bed sweet, I can dump this in any image dir I have
00:41 rue_bed tho I think I'll make it say the image title at the bottom later
00:42 rue_bed you seeing this!
00:42 rue_bed its sweeet!
00:42 rue_bed waaay better watching this as a sideshow
00:46 rue_bed I put one in arm7 too
02:02 mrdata how long is the slide show?
02:42 GuShH RifRaf: http://gushh.net/tmp/dscn6174f.jpg
02:43 GuShH 10 minutes later http://gushh.net/tmp/dscn6182f.jpg
02:43 GuShH it was frozen shut!
02:43 GuShH now it works.
02:43 GargantuaSauce wow
02:43 GuShH it's a jacobs so I figured it was worth salvaging
02:44 GuShH (it looked like it came out of the titanic)
02:46 GuShH now let's try it with this thing http://gushh.net/tmp/dscn6125f.jpg
02:46 ShH g
03:42 mrdata nice vice
03:43 Tom_itx bit rusty like GuShH!
06:38 rue_bed http://ruemohr.org/~ircjunk/robots/arm7/slide.htm
06:39 Tom_itx you made a slide for your arm?
06:40 rue_bed sideshows
06:40 rue_bed I just have to make a text file with the image list
06:40 Tom_itx i want to pause it!
06:40 rue_bed go to bed!
06:40 rue_bed no! no user control!
06:40 rue_bed :)
06:40 Tom_itx no i'm going to work
06:40 rue_bed I'm missing a cat
06:40 rue_bed I'm worried
06:41 rue_bed the other cat did something funny
06:42 rue_bed Tom_itx, I'm thinking of adding image names and pause
06:42 Tom_itx i can right click and 'view image' to pause it
06:42 rue_bed yup
06:43 Tom_itx i'm leaving
06:43 rue_bed bye!
07:20 deshipu rue_bed: is it complete?
07:20 rue_bed yes
07:21 deshipu \o/
07:21 deshipu can you make it play chess? :)
07:47 TheRustyToelle hi
07:49 TheRustyToelle q
07:49 TheRustyToelle w
07:49 TheRustyToelle e
07:49 TheRustyToelle r
09:23 rue_house deshipu, still playing with software
09:24 rue_house I ran into a problem where I seemed to need more than one arm for any of the things I wanted to do
13:11 trshfx hi
13:16 mrdata lo
13:31 GuShH Tom_itx: thanks for the rusty comment, it's true. so I opened up a bottle of wine yesterday to de-oxidize myself
13:31 trshfx lol
13:31 GuShH I gave some to the vice and we got into a big fight.
13:31 ShH eyer
13:32 GuShH it just needs new jaws and some TLC
13:44 GuShH Tom_itx: parksinsons perfect vice No 8 british made, who knows when. it has the split nut / quick release, awesome stuff.
13:44 GuShH I know the guy was joseph parkinson, patented the first one in 1880s
13:44 GuShH he then worked with his son but no clue what happened after that
15:27 Oracle989 Is there a good way to know which pin is the signal pin and which are the + and - power pins on an RC receiver?
15:27 Oracle989 My Hobby King transmitter didn't come with a manual.
15:27 fluffywolf they're all the same. google.
15:29 Oracle989 Neat.
15:29 Oracle989 How do I use its signal? Is it just PWM that I can read?
15:29 Oracle989 And if so, how do I read that with an Arduino?
15:29 fluffywolf it's similar to PWM. again, google. :)
15:30 fluffywolf it's a short pulse with a long pause, with the length of the pulse telling you the position, and the pause largely ignorable.
15:31 Oracle989 I'm trying to control my ground robot with an aircraft tx, which is not the best plan but it'll work.
15:31 Oracle989 I'm thinking I won't let it turn while going forward.
15:31 Oracle989 For ease of code.
15:31 Oracle989 Nor will I have it care how far I've got the stick, if that helps.
15:32 Oracle989 I just want to tell it forward, back, left, or right, and use another channel to turn the water pump on or off.
15:32 Oracle989 I don't have any toggles, though.
15:32 Oracle989 Which makes this fun.
15:32 fluffywolf not the best plan, also illegal.
15:32 Oracle989 It is?
15:33 fluffywolf the bands are allocated for specific uses (ground, air, etc)... mostly to keep ground people from accidentally interfering with aircraft people, and creating a safety hazard, or at best, a very expensive whoops.
15:33 Oracle989 I'm not operating it anywhere near in range of an RC air field.
15:34 Oracle989 So I find it hard to imagine anyone would care.
15:34 fluffywolf of course, chances are no one will ever notice.
15:34 fluffywolf what method of locomotion does your robot use?
15:34 Oracle989 And interference is much less common on the 2.4GHz stuff than the old radios, I think.
15:34 Oracle989 Motors driving treads
15:34 fluffywolf ah, you're using modern gear. I think the 2.4 stuff is good for any use.
15:35 Oracle989 Shitty modern gear, but modern.
15:35 fluffywolf motors driving treads will have no problem, at all, going and steering at the same time.
15:35 Oracle989 I, however, may have problems coding that to 1) not suck, and 2) be proportional to how far the stick is held.
15:36 Oracle989 I don't have very long to make it work, I was just asked this morning to bring it to demo at an event tonight, and I need to overhaul the radio system to make it better for that use.
15:36 Oracle989 And, well...make it work at all.
15:37 fluffywolf left motor = forwards/reverse stick + left/right stick. right motor = forwards/reverse stick - left/right stick.
15:38 fluffywolf sure, you could do fancy control algorithms, ramping, etc, but two lines of math is enough to make it usable. :P
15:39 fluffywolf that's assuming both sticks are normalized around 0, i.e. -1 to +1, or fixed-point in a range that won't overflow.
15:40 fluffywolf I'm not familiar with the arduino's hardware, but standard approaches for measuring a servo pulse would be to use an input compare/timer register setup, or if you have enough cpu spare, poll repeatedly and time long long it's high manually.
15:41 Oracle989 My thought was do an analog read on the pin for the forward and turn channels, and if I pull a pin high it saves that value to a baseline.
15:41 fluffywolf you're looking for the length of the pulse, not the duty cycle... all that matters is how long the pulse is. the pause between pulses may vary, and will be different on different radios.
15:41 Oracle989 Then if the forward channel is higher than the baseline, forward, lower, backwards, at baseline, stop.
15:42 Oracle989 Turn channel low, left, high, right, at, no turn.
15:42 fluffywolf pulses are 1 to 2ms long, and you need to accurately time it.
15:42 Oracle989 Oh.
15:42 Oracle989 I can't find any documentation for mine.
15:42 fluffywolf as I said, it's standard. they're all the same.
15:43 fluffywolf 1.5ms is zero/neutral/center/whatever, then 1ms and 2ms are extremes in each direction.
15:43 fluffywolf this is why servos from any brand plug into radios from any brand. :)
15:44 acle989 headscrat
15:44 Oracle989 So how do I time that?
15:44 fluffywolf that depends on your hardware. I'm not an arduino expert. the uC may have hardware that will do it automagically, or you can poll repeatedly, take note of some system clock when you sense it going high, subtract when it goes low...
15:45 Oracle989 Guess I should ask #arduino, then?
15:45 fluffywolf http://arduino.cc/en/Reference/pulseIn is the first google result, and there's many, many.
15:45 fluffywolf a search engine is your friend. :P
15:46 Oracle989 So I just need to find out how long my radio waits between pulses, then?
15:47 fluffywolf no, as I said, the time between pulses varries and should be ignored.
15:47 fluffywolf all that matters is how long each pulse is.
15:47 Oracle989 Don't I need a timeout value for pulseIn()?
15:48 fluffywolf googling for more servo-specific stuff finds things like http://forum.arduino.cc/index.php/topic,22140.0.html
15:48 fluffywolf someone else's code and demo program to decode servo input from a r/c radio.
15:48 Oracle989 I don't have any servos.
15:49 fluffywolf ... decode the input that would be going to a servo, but is instead going to your arduino.
15:51 fluffywolf pulsein is probably simplest for your task
15:51 fluffywolf as to how to actually use it, ask in an arduino-specific channel.
15:52 fluffywolf "normal" spacing between pulses might be 20ms, so set a timeout of, say, 100ms, so it doesn't glitch with a little bit of static, but does recognize when it's actually lost contact.
16:01 fluffywolf bbl
20:34 rue_bed Oracle989, what you making?
20:34 Oracle989 rue_bed: An electrical fire, most probably.
20:34 Oracle989 Followed closely by a tangled pile of hammer-beaten scrap sitting next to a pile of empty beer bottles.
20:34 rue_bed hmm
20:34 rue_bed sounds quite art based
20:36 Oracle989 As it turns out, I don't think it'll be an electrical fire, I'll be finding my own accelerant for it.
20:40 rue_bed just the one project?
20:40 rue_bed did you see my sideshow?
20:41 rue_bed its ajax, I'm rather impressed with it
23:07 rue_house cat has not come back
23:08 robotustra wait longer
23:08 rue_house its been about 6 days
23:09 robotustra old?
23:09 rue_house no
23:09 rue_house few years old
23:09 robotustra shecat or he cat?
23:09 rue_house she
23:09 robotustra marriage?
23:09 rue_house no
23:09 robotustra or somebody ate her?
23:10 rue_house dunno
23:10 rue_house she wasn't good about cars
23:11 robotustra hm
23:11 rue_house yea
23:11 rue_house lots of reasons to worry
23:11 robotustra did have driving licence?
23:28 rue_house no
23:28 rue_house but she got annoyed easy, so its prolly a good thing
23:42 MrC123 Tip of the day: Always take the high road. It often provides an excellent view of the train wreck on the low road...
23:47 rue_house long route always seems to pay off for me