#robotics Logs

May 19 2015

00:56 zhanx Evening
01:10 Anniepoo =8cO
10:32 MondaytoFriday Hello all.
10:32 deshipu hi MondaytoFriday
10:34 MondaytoFriday Looking for somebody who has experience with the PCA9685. I'm running 12v fans, I've set mode1 and mode 2 but my fan runs at full no matter what. My theory is that it's wired wrong and the fan is not getting any pwm signal at all and that's why it's off. The fan requires a 5v pwm signal which I thought the 9685 could handle.
10:35 MondaytoFriday Do I need to ground (v-) to the board with the pwm signal? I can't run 12v through the board obviously.
10:36 deshipu all grounds have to be connected
10:36 deshipu otherwise you are getting random voltages
10:38 MondaytoFriday So only v+ should be on my external driver, every other wire should be connected to the pi including the v- wire at the ground?
10:38 MondaytoFriday By pi I mean PCA9685
10:41 MondaytoFriday My concern is the board itself says 6vmax
10:41 MondaytoFriday Which for PWM is great.
10:51 deshipu well, voltage is always *between* two points
10:52 deshipu if you don't have the ground connected, then the pwm signal you are sending has no voltage, it's just hanging in the air
10:53 deshipu it has to be relative to something
10:53 deshipu current will not flow in an open circuit
10:54 MondaytoFriday So I should be grounding the PCA to the 12v supply not the raspberry pi then.
10:54 MondaytoFriday The fan runs at full, if v+ and v- are connected to the power supply.
10:55 deshipu normally you connect all grounds together
10:56 deshipu unless you are isolating them optically or inductively
12:05 LiohAu rue_house: hey
12:06 LiohAu did you already build an humanoid hand?
12:20 SpeedEvil I built a couple of humanoid hands.
12:20 SpeedEvil It was a while ago noe
12:37 LiohAu_ hm was disconnected..
12:38 LiohAu_ So, SpeedEvil, I was planning to use cables to move the fingers. I have 2 options to shorten theses cables, using cheap servomotors, or DC motors
12:38 LiohAu I know that servo basically are DC motors with an encoder
12:39 LiohAu If I choose the servo option i'll have to use a winch servo horn (like that : http://www.rcboyz.com/images/P/aceac6842.jpg)
12:40 LiohAu and the servo horn must be large enough so that the little rotation that can be made by the servo (usually 180°?) can shorten the cable enough.
12:42 LiohAu If I use a dc motor, the horn diameter will only depends on the motor rotation speed.
12:43 LiohAu brb
13:22 veverak HMM
13:23 veverak isn't there pattern for system that is made of multiple parts that can be enabled/disbaled ?
13:23 verak is programming (agian) brain of r
13:23 veverak and want to try this approach
15:27 MarkX hi
16:21 ordeal whoami
16:22 ordeal who
16:24 SpeedEvil ##existentialism
16:41 chris_99 heh
20:14 rue_house lio
23:25 rue_shop3 Rule 0: Dst(0) += (Src(0) x 1.00) + 0.00
23:25 rue_shop3 Rule 1: Dst(1) += (Src(1) x 1.00) + 0.00
23:25 rue_shop3 Rule 2: Dst(2) += (Src(2) x 1.00) + 0.00
23:25 rue_shop3 Rule 3: Dst(3) += (Src(4) x 5.00) + 6.00
23:25 rue_shop3 Rule 4: Dst(4) += (Src(4) x 1.00) + 0.00
23:25 rue_shop3 Rule 5: Dst(6) += (Src(5) x 1.00) + 0.00
23:25 rue_shop3 Rule 6: Dst(6) += (Src(6) x 1.00) + 0.00
23:25 rue_shop3 Rule 7: Dst(7) += (Src(7) x 1.00) + 0.00
23:26 rue_shop3 this will give me the power I need to take over the world
23:26 rue_shop3 HAHAHAHAHAHAHAHAHAH
23:37 rue_house hey, that was my idea
23:37 rue_house really dude you just took my idea
23:37 rue_house I used it in the state machine, remember?
23:40 rue_house addrule A<83 B=A+1 -20
23:40 rue_house addrule A==83 D=0x00 -40
23:40 rue_house addrule A<83 D=D|B -30
23:40 rue_house REMEMBER!?
23:40 rue_house but my rules had priorities
23:40 rue_house and conditions
23:40 rue_house so your system sucks
23:42 rue_house I HATE EATING
23:42 rue_house snacking, snacking is ok