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Using a prop to drive servos on a biped — Parallax Forums

Using a prop to drive servos on a biped

StickySticky Posts: 42
edited 2010-04-10 16:10 in Propeller 1
If somebody has had success driving multiple servos (like 6 or more at the same time) on a biped would you let me know how you've done it and what kind of code you've used? I am not looking for help with a project but just how this has been done if it has been done.

Comments

  • StickySticky Posts: 42
    edited 2010-04-10 15:29
    Also to clarify a bit, I mean any prop driven board, Propeller Robot Control Board, demo board, Propeller Servo Controller USB and standalone on a breadboard.
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2010-04-10 15:34
    Sticky,

    There is an object in the OBEX that will drive up to 32 servo's. For your biped it would be up to you to orchestrate the servo motion. The Servo32 object will allow you to set and forget a servo position or ramp to a position while the remainder of your code processes other aspects of your project.

    obex.parallax.com/objects/51/

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • StickySticky Posts: 42
    edited 2010-04-10 15:59
    Thanks Beau, greatly appreciated, but I am really looking for someone that has one working in the real world, I'll clarify a bit more, I have been working on this for four months with no success. I have used the Servo32v7 object and it craps out. It just doesn't work, driving the servos directly from the program does the same thing. For me it works with two or maybe servos, then it either resets or acts irregularly. I have used all of the aforementioned boards with various power supplies batteries, wall units and I can't get it to work. So I am not able to do it, so I will use someone else's methods, I would just like to get something that is known to work.
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2010-04-10 16:05
    Sticky,

    Are you using a series resistor of 4.7K on the signal wire to the servo? ... This helps to attenuate electrical noise that can enter back into the Propeller from the servo

    Are you using a separate power supply for the Servo's? ... Servo's can draw an excessive amount of current when moving

    Are the grounds between the separate power supplies tied together? ... This needs to happen to create a proper reference for the servo signal.

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • StickySticky Posts: 42
    edited 2010-04-10 16:10
    I will give these suggestions a shot and see. Thanks again
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