This book deals with tracking of sun light by solar cells in two dimensions (2-D), to achieve maximum sun light, which in turn maximize the efficiency. Whole tracking is done with implementation of proportional plus integral plus derivative (PID) controller, through coding in micro controller. This technique not only makes the reduces error to approach zero, but also increases stability. This book contains very suitable material for beginners, who intend to do research in PV cells and solar tracking.