Problem with number of pulse of encoder

I am using this kit for my robot https://www.parallax.com/product/570-00080. In the document, it says there are 1920 pulses for a rev with gear. I believe I have problem when measure the velocity of the motor by reading encoder. I got 28 pulse per 100 msec means 6.8 sec/rev if 1920 is a correct number. But by look at the wheel and use a time clock I get about 5 sec/rev. I wrote a small test to read the pulse only and spin the wheel manually I got about 1438 pulse/rev. So does the encoder not work as description?

Comments

  • That's pretty close to the 1440 pulses per rev for the 30:1 gear on the V1.2 wheel kit.
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  • There was some post about a batch with encoders having wrong count of pulses a while ago.

    I think @Ken posted about. Call Parallax support for confirmation. Very helpful and friendly people.

    Enjoy!

    Mike
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  • Thanks guy, I confirm it is 1440 count.
  • msrobots wrote: »
    There was some post about a batch with encoders having wrong count of pulses a while ago.

    I think @Ken posted about. Call Parallax support for confirmation. Very helpful and friendly people.

    Enjoy!

    Mike

    I'm remembering Chris Savage commenting on it.

    The motor supplier changed from a 16 transition per revolution encoder disk to a 12 transition per revolution encoder disk.

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