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Unread 12-02-2005, 12:56
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Kevin Watson Kevin Watson is offline
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Re: Third Encoder Channel

Quote:
Originally Posted by SlimBoJones
1) Must interrupts 3-6 be enabled/disabled as a package? i.e. you cannot ONLY enable 3, but not 4-6? I am using two encoders and the Hall Effect sensor, and need only 3 interrupts, and would rather not have to enable 6 of them.
Yes, but it's not a big deal. If you're not using the other three interrupts, just treat the interrupt the same way you would the first two. The only added step is to determine which edge caused the interrupt to fire off.



Quote:
Originally Posted by SlimBoJones
2) If Q1 is true, and we enable 3-6, should we move the phase-B signal on I/O 6 to 7 in order to avoid unnecessary interrupts?
Yes, definitly. Just edit encoder.h to specify which digital input you've moved it to.



Quote:
Originally Posted by SlimBoJones
3) Does phase stretching circuit described in the threads above allow a faster count rate because it prevents the phase-B state from changing (to the wrong state) before the interrupt is serviced?
Yes, and it works really well.



Quote:
Originally Posted by SlimBoJones
I know some of these should be pretty obvious, but Team 188 is running the Grayhill 63R256 encoders, and our count rates are pretty high.
The above circuit will increase your maximum count rate by a factor of four.

-Kevin
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Kevin Watson
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