Abstract: This paper introduces a peristaltic pump device implemented by a microcontroller for use in a filling production line. It can realize manual or automatic single, multiple, and mixed filling in the filling production line, with a filling accuracy of 1‰ml. Keywords: Microcontroller; Stepper motor; Peristaltic pump; Filling Modern pharmaceutical manufacturing processes, such as injections and bottled liquids, mostly utilize microcontrollers or other intelligent devices for automatic filling. Microcontroller-implemented filling often converts the filling volume into pulse counts according to formulas, and the microcontroller controls a stepper motor to drive the peristaltic pump according to a control program. However, since the motor's starting process is a nonlinear curve with variable acceleration, it is difficult to accurately reproduce the motor's starting process using a simple linear constant coefficient method. The pulse count calculated by this method is also inaccurate and has a large measurement error. This paper uses the exponential logarithmic method to achieve nonlinear fitting of the starting process. The resulting pulse linear constant method better matches the motor's starting characteristics and can achieve higher measurement accuracy. This paper describes a stepper motor-controlled peristaltic pump device based on the AT89S58 microcontroller, which can operate in automatic or manual mode. In automatic mode, it offers three dispensing methods: single-dispensing, multi-dispensing, and mixed dispensing. For multi-dispensing, the dispensing quantity, speed, backflow rate, and main control mode are set, along with the number of dispensing cycles and pause time. The microcontroller controls the stepper motor's operating state based on the set values ​​for dispensing quantity, backflow rate, number of dispensing cycles, pause time, and speed, and its control output is a time-scale curve. The dispensing cycle and dispensing quantity parameters can be input by the user via keyboard according to different requirements and stored in the EEPROM. In manual mode, the microcontroller only performs a monitoring function. For details, please click: Application and Development of a Stepper Motor Control Device Based on a Microcontroller