Re: Encoder counts/revolution

--- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:

Dear Mr. Marconett,

I am not sure but maybe this is the kind of problem you are
talking about. Suppose a 0-360 degree dial on a rotating shaft
reads 31.07 degrees at some time and the shaft then rotates say
through another 2351.35 degrees. Now what does the dial read?

If we add the two numbers we get 2382.42 degrees. Now form
2382.42/360 = 6.61783... . Kill the integer part (6.) and
multiply the result by 360, i.e. 0.61783...X360 = 222.42
degrees. This is what the dial will read. So the algorithm
is:
add the start reading and the amount of advance
divide by 360
take the fractional part (i.e. subtract the integer part)
multiply by 360

Hope this helps.

Sincerely,
Barry




> Now what I'm having fun with is the calculations needed to calculate
> moves around arcs. Getting the start angle, and end angles that
"wrap"
> around 0 degrees is a problem! Even the quadrant boundaries cause
> problems in calculations! Anytime something "chases it's tail" as
in
> moves around arcs, or circular buffers where a fixed "depth" exists
> cause similar problems, as I've recently found out!