At 08:29 PM 2/27/2011, you wrote:
>Hi all,
>
>I'm working on a solar tracker and would like to calculate the
>sunrise/sunset position. The aim is to use a PIC controlling a
>pair of steppers and gear trains
>
>One algorithm frequently cited is this one
>
>http://williams.best.vwh.net/sunrise_sunset_algorithm.htm
>
>That page is reproduced below
>
>Now, the first problem has arisen. Do I assume correctly that the
>C function "floor" is similar to INT ? ie, the decimal part of a result
>is discarded ?
>
>http://en.wikipedia.org/wiki/Floor_and_ceiling_functions
>
>15th November 2010, day of year (by addition) 319
>
>31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31  + 15 =3D 319
>
>day =3D 15, month =3D 11, year =3D 10

                           ^^^^^^^
Here's the problem, you're in the wrong millennium! year !=3D 10 ; year =3D=
 2010

Now it will work out to 319. (N3 =3D 2)

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the rewar=
d"
speff@interlog.com             Info for manufacturers: http://www.trexon.co=
m
Embedded software/hardware/analog  Info for designers:  http://www.speff.co=
m



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