At 07:06 PM 9/30/97 -0500, you wrote:
> Any general ideas on measuring RPM (a few 100 to 2000) on a
>PIC (16C71) for serial transmission to a remote receiver? PIC is also
>doing a/d reads, but RPM would be priority.

Pack voltage and RPM??

> And, any pointers to a photo tach circuit that will pick up 2 blades
>(1inch chord) at about a foot with the sky as background?

Most standard phototransistors would do this quite well.  Only adjustment
would be the bias applied to the base.  Super-simple.  Done that for others
already.  Have my own 0-60K RPM tach, accurate to +/- 1 RPM @ 60K (totally
useless functionality - even +/- 50 RPM is adequate).

Andy

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Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
          Hardware & Software for Industry & R/C Hobbies
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