heaven, it was never suggested by me to implement this formula!
Since I will be using keil C and the 8051 has nothing else to do so why not implement it. Else I can pre calculate position / time and date and store these values in eeprom for a certain long/lat coordinates.
To make things more hairy I can add a gps receiver board to locate the exact position of the solar cell and make it universal.
Since this is not a production project, cost is irrelevant and someone else is paying I can have fun building it.
The philips P89C51RD2 will be my choice because of its bootloader to program of the serial port using flash magic?
Regards
Mahmood