Design of high precision optical power meter based on MSP430

Aiming at the high error caused by the integral method for the traditional optical power meter, from the application point of view, a high-precision optical power meter with MSP430 is proposed. The photoelectric sensor converts the light signal into mA current signal, through a negative feedback current amplification, and then through a differential amplification and filtering circuit, and converts anolog signal into a digital signal through a 24-bit high-precision AD chip. The optical power is calculated using recursive and median digital filter. The measured value is displayed on the LCD. The optical power curve is also displayed after through the Savitzky-Golay filter in measurement phase. The experiment proves that the optical power meter has an error of less than 0.3%, low power consumption, stable system, friendly display interface, it can store measurement data and display optical power curve.