Based on micro controller unit（ MCU） and biaxial driving mechanism

a solar position sensor consists of a square-based plate

on which a 10 cm height

double layer cross-shaped light baffle is fixed. The baffle divides the base plate into six light-receiving sections. In each section

there is a hole with diameter of 1 mm with a photoresistor installed underneath to sense the illuminance therein. The rotation direction of the motor is determined by the illuminance differences of sections I-IV. The changes of illuminance in sections V＆VI are used to judge whether the apparatus is in line with the sun. The applicatons of Δu empirical parameters is set in direction judgement and "self-comparison method" is used in tracking and control

effectively reduce the negtative effects brought by the discrete property of photoresistors and promote tracking precision up to 0. 2°.