STC microcontroller SMBUS communication MLX90614 infrared temperature sensor, and The main purpose of this document is to describe how to achieve the MCU and infrared thermometer MLX90614's SMBus communications, and a brief description of the use of the microcontroller's PWM output pulse MLX90614 measure and calculate the relevant temperature. Code is based STC12C5604AD microcontroller. Examples given by the C language reads MLX90614 object temperature, writing data to the MLX90614, and the PWM pulse and other measurements and calculations.