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Unread 06-11-2012, 13:41
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Re: paper: Talon, Victor884, Victor888, and Jaguar speed vs torque tests

Quote:
Originally Posted by Ether View Post
Paul, would it be useful to ask the folks at WPILib to change their 884 (and future 888) driver to use a period of 5ms instead of 17ms? I realize it probably makes little difference in the vast majority of cases, but there may be teams who want to close a loop at 10ms.


The Victor 884 class runs at 10ms. It's hard to tell from the comment if it was tested at 5ms.

Code:
    /**
     * kDefaultPwmPeriod is "ticks" where each tick is 6.525us
     *
     * - 20ms periods (50 Hz) are the "safest" setting in that this works for all devices
     * - 20ms periods seem to be desirable for Vex Motors
     * - 20ms periods are the specified period for HS-322HD servos, but work reliably down
     *      to 10.0 ms; starting at about 8.5ms, the servo sometimes hums and get hot;
     *      by 5.0ms the hum is nearly continuous
     * - 10ms periods work well for Victor 884
     * - 5ms periods allows higher update rates for Luminary Micro Jaguar speed controllers.
     *      Due to the shipping firmware on the Jaguar, we can't run the update period less
     *      than 5.05 ms.
     *
     * kDefaultPwmPeriod is the 1x period (5.05 ms).  In hardware, the period scaling is implemented as an
     * output squelch to get longer periods for old devices.
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