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Thread: Sloth Robot

  1. #11
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    Athens, GREECE
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    Quote Originally Posted by erco View Post
    Thanks, that's great, steliosm!

    I just saw that you are in Athens, what a great city! I ran the marathon there in 1999. I only know one other Greek roboticist, Nikos G. A very smart and enthusiastic teacher, you can find him at https://forums.parallax.com/profile/NikosG

    And do you know the guys at Muse Robotics? http://www.muserobotics.com/contact.html
    Actually, I don't know any of those guys. I'm more into "connected objects" rather than robots.
    Sadly, there used to be a Greek robotics forum (grobot.gr) but it's now long gone. I hope now that robotics is a part of the curriculum to actually see this science field to take off in Greece.
    ~stelios

  2. #12
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    Sep 2016
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    I got two pca9685 pwm boards working https://www.youtube.com/watch?v=YtKq...Ku1sLw&index=2

  3. #13
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    Jul 2011
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    Los Angeles, CA
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    Lovely, Stanley! Yes, those 12 servos will suck a lot of current. Even more under load! Use good batteries and big fat power wires.

  4. #14
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    Sep 2016
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    18 servos erco. the pca9685 board don't like not enough power for servos although it has own 5V supply and the servo supply is totally independent.
    There's a set all channel command and I use scale..arduino map function but in basic to convert degrees to pulse width. This sets all 18 servos to 90 degrees.....
    but with not enough power all servos go to 0 degrees.
    My thought is a 8 A bridge rectifier and 7.2V li-ion,4 batterys. The bridge is 2 diodes in series twice so should drop 7.2V to 5V. I've ordered a dc-dc 8A buck converter anyway.
    If you nick the init code for these boards they'd work with picaxe.
    Also , you can take a wire off the pot in the servo,connect to a-d and get servo position. There's probably a 16 channel a-d i2c chip some where..it seems familiar..I might have some.
    I could then teach it to walk. otherwise it's trig or tables.
    It needs longer legs so less strain on servos...from first thoughts an tests.
    Last edited by stan74; 03-08-2018 at 15:41.

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