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programming Hitec servo HS805-BB with BS2 — Parallax Forums

programming Hitec servo HS805-BB with BS2

AnnoyingAnnoying Posts: 50
edited 2010-01-18 09:11 in Robotics
I am trying to program the hitec servo HS805-BB that has been modified for continuous rotation with the basic stamp 2 and I can't seem to control the speed.

Using the simple code

FOR counter = 1 TO 100
PULSOUT 0, 1
PAUSE 20
NEXT

I get the same speed when I change the pulsout duration to 1000...

The data sheet says neutral is 1.5 ms. It also says for the direction, : [font=WXLPYS+Arial size=1][font=WXLPYS+Arial size=1]

CLOCK WISE/PULSE TRAVELING 1500 TO 1900usec



but it has been modified for continuous rotation, so I'm confused about how to set the pulse for a slower speed.

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Comments

  • W9GFOW9GFO Posts: 4,010
    edited 2010-01-18 07:38
    First off your PULSOUT value should range from 500 to 1000 with 750 being center. Each PULSOUT increment is 2uS.

    Create a program that sends a PULSOUT of 750 continuously;
    DO
PULSOUT 0, 750
PAUSE 20
LOOP


    Adjust the potentiometer on your continuous rotation servo so that it stops turning.

    Now when you send PULSOUT 740 it will turn one direction and PULSOUT 760 will turn it the other.

    If your servo mod involved replacing the potentiometer with resistors (no way to adjust) you will have to find the PULSOUT value that results in no movement and use that as your center PULSOUT value.

    Rich H

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    The Simple Servo Tester, a kit from Gadget Gangster.
  • AnnoyingAnnoying Posts: 50
    edited 2010-01-18 08:08
    I had the company that I ordered it from modify it for me so I don't know how they did it, but I have tried every pulse value and I keep on getting the same speed. shouldn't the speed vary as the pulse is changed?
  • Roy ElthamRoy Eltham Posts: 3,000
    edited 2010-01-18 08:17
    Do you have a plain BS2 or one of the other models like BS2p or pe or px or whatever? If you have one of the faster models you'll need to adjust the numbers accordingly.

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  • AnnoyingAnnoying Posts: 50
    edited 2010-01-18 08:21
    just a plain BS2...
  • W9GFOW9GFO Posts: 4,010
    edited 2010-01-18 09:11
    Hmmm, don't know. If you are confident that there are no problems with the pulses that you are sending I would take apart the servo and see if the potentiometer (if present) has moved out of adjustment.

    In some modifications you can adjust the potentiometer without taking apart the servo by removing the servo horn and inserting a small screwdriver where the screw was. Other modified servos may have a small hole in the side for accessing a trim pot. Some retain the pot but you have to take the servo apart to access it. And others replace the pot with a couple resistors.

    Maybe call the place you bought it from - Servo City?

    Rich H

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    The Simple Servo Tester, a kit from Gadget Gangster.
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