本文研究并設計了一種基于單片機的高精度水位監控儀，從硬件設計、軟件設計與系
統抗干擾設計三個方面詳細描述了整個系統。系統選用了高集成度的混合信號系統級芯片C8051F021，實現了信號的采集和處理，并且完成了AD421 與單片機的SPI 接口任務，協
調了它與AD7705 芯片和單片機共同構成的SPI 總線系統的關系。系統解決了以往的水位監控儀中存在的問題，達到了高精度水位測量儀器的各項標準。
關鍵字: 水位監控；單片機；模數轉換；
Design of Water-level Measuring System with High Accuracy based on SoC ZHANG Yixiang (1. Shanxi Mechanical Electrical Profession Technology College 046011 2. Taiyuan University of Technology Shanxi Taiyuan 030024) Abstract: A new intelligent water-level system is developed in this paper. It described the system according to the hardware design, software design and anti-jamming design. We choose an advanced integrated SOC(System on Chip) microchip C8051F021 as the main controller; Realization of signal sampling, processing and its conversion in the MCU; Additionally, a 4~20mA current output channel to provide system check-up using AD421 .In the system, AD421，AD7705 and the microchip compose SPI bus. This water-level meter has satisfied all the request of system, settled many problems ever existed in the previous ones and attained high preciseness as a good meter.
Keywords: Water-level; SoC; A/D Convert