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Unread 30-01-2013, 14:46
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Ether Ether is offline
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Re: Measuring motor speed

Quote:
Originally Posted by fovea1959 View Post
Ether: we get one count per rev with that magnet. I believe the student had the averaging set to 1
The 6.525 us quantization of the FPGA timing of the period should give you about 38 RPM peak-to-peak jitter at 18,600 RPM with sample size set to 1. That's about 0.2% p-p. Pretty darn good.

Quote:
I am anticipating doing bang-bang, and frankly, I don't know how fast we'll run it.
Nice thing about bang-bang is it doesn't care much if your control period has jitter. Since the bang-bang code is so minimal, you can run it fast without chewing up much CPU.



Last edited by Ether : 30-01-2013 at 14:49.