how to find firing angle to charge battery.

[love_electronic]

i want to design a battery charger based on microcontroller (for e.g 12v 4A SLA battery).The technique i wanna use is full controlled battery charger based on scr.
i wanna know that, how i can find the firing angle and what parameters should i measure in microcontroller to calculate the firing angle (like battery voltage,current).
hope you guys will help me out.

 

[FvM]

You may want to implement a constant current/voltage controller and set the firing angle in closed loop feedback rather than "calculating" it.

 

[love_electronic]

yes FvM.from where i start writing a program?