Crank Angle Sensor resolution - Re: Old 486 ..

[Ludis Langens]

"Diehl, Jeffrey" wrote:
> 
> If the clock frequency stays constant and the RPM ranges are all the same
> size throughout the power band, the number of clock counts per flywheel
> event will change with RPM.

Yes, of course.

> However, if this counter value is used to
> access a memory to look up, lets say, ignition timing, then we will waste
> much of the memory space because the counter will skip many of the
> locations.

Huh?  Your table could be indexed any way you want.  If you are willing
to accept a processor speed penalty, each table entry could correspond
to a different sized range of timer counts.  For a practical system, the
timer counts should be used to compute the engine rpm in whatever
increments of rpm you find useful.  (Yes, this rpm calculation will be
less accurate the higher the rpm.)  This computed rpm can then be used
as a table index.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
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