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Servo Motor Issues — Parallax Forums

Servo Motor Issues

obie25obie25 Posts: 1
edited 2010-01-31 00:58 in Learn with BlocklyProp
Hi guys,

I am working with several students who are sending various pulse widths to the servo motors and map out the the various speeds the wheels will go.

They are entering various ranges as recommended in the exercise yet (650 to a max of 850)...yet....the motors always turn the same number of revolutions no matter what pulsewidth is entered into the program.· I have reviewed their basic program and the calculations all appear okay.

Anyone have any other thoughts?!

Thanks!


·

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-14 03:09
    Something is wrong with what they're doing. For continuous motion servos, PULSOUT values less than 750 should result in rotation in one direction and values greater than 750 should result in rotation in the other direction. The difference between the value used in the PULSOUT and 750 should approximately reflect the speed of the servo. The servo will only continue to move if pulses continue to be sent to the servo. I suggest you post one of the programs and include a schematic or clear detailed description of what's connected to what.
  • FranklinFranklin Posts: 4,747
    edited 2010-01-14 04:44
    Also which stamp are you using?

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    - Stephen
  • tarekulmamuntarekulmamun Posts: 1
    edited 2010-01-20 07:58
    The order in which controllers are daisy chained determines their I2C address. Addresses are somehow automatically configured by the hardware with the controllers closer to the NXT having the lower addresses.

    So, if you're using daisy chaining, make sure the physical daisy chaining order corresponds to the parameters that are specified in the labVIEW (or NXT-G) blocks/VIs.

    Also try non-daisy chaining and using two sensor ports: one for each of the two Controllers. You'll have to make minor changes to the program for the "port" and "controller number" inputs. Once you get this working properly, thn you can try to convert to daisy chained arrangement.
  • RoboticsProfessorRoboticsProfessor Posts: 54
    edited 2010-01-31 00:58
    Attached·is some test code I made to see many different servo speeds.

    I used ports 14 and 15. Make sure you change those numbers if you use·other ports.

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    Richard Vannoy

    Programming and Electronics Instructor
    www.RichardVannoy.info
    bs2
    bs2
    Servo Speed Test.bs2
    741B
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