thanks for the reply,
SO i consider azimuth angle need to be if tracker will move in horizontal axis, elevation / altitude angle for the vertical axis.
any other point need to be considered like Seasonal change ,shadow length during coding while calculations.
DO you know any link which gives information on calculating backtracking algorithms to avoid shadowing,increase efficiency
If i wanna run Nrel code. Which controller is best in arduino. http://www.nrel.gov/midc/spa/
I think that when we track sun position based in calculations we don't need to use seasonal correction, cause calculations are based in time and day of the year.
I don't know any backtracking algorithms to avoid shadows. Try to place your trackers where there are no physical shadows, and away from each other.
Nrel code is very accurate, but i dont think its needed for photovoltaic panels solar tracker, since you lose 1% of direct suns power at 8 degrees misalignment.
Keep things simple.