基于P89LPC954单片机的八路四声道超声波流量计测量电路设计

Design of the Measuring Circuit of Eight-way Four-sound channel Ultrasonic Flowmeter Based on P89LPC954 MCU

该文介绍了超声波流量计的工作原理，着重描述了该超声波流量计测控系统的结构及其八路四声道测量电路设计。该系统以P89LPC954单片机为核心，其外围电路模块主要包括超声波信号的发射与接收、模拟开关、峰值采样、D／A转换、自动增益控制、显示等。此外，还包括FPGA数据传输及数据分析等功能。应用程序采用模块化编程模式，以方便升级和调试。该流量计主要应用于超声波气体流量测量，实验结果表明，其电路工作稳定，测量精度较高。

This paper introduces the working principle of ultrasonic flowmeter with the emphasis on the description of the structure of the measurement and control system and the design of eight-way four-sound channel measuring circuit of the ultrasonic flowmeter. In the system, P89LPC954 MCU is adopted as the core., its peripheral circuit modules include ultrasonic transmitter and receiver, analogue switch, peak value sampling, DIA converter, AGC, display, FPGA and so on., in addition to contain the functions of FPGA data transfer and data analysis. Modular application programming model is easy to upgrade and debug. The flowmeter is mainly used in ultrasonic gas flow measurement. The experimental results show that the circuit is characterized by its stable operation and higher measurement accuracy.