Hydrometry Monitoring System Design Based On MCU

China is located in the monsoon climate zone and torrential rain and flood often happens.Affected by this monsoon climate, most of our region is hot wet and more rain in summer.Not only for short duration, high strength local rainstorm often happens, but also rain in wide range of the valley with long duration often happens.Annually, floods disaster happens in large range of our nation with varying degrees. Therefore, Perfect hydrological monitoring can help real-time monitoring hydrological in all regions with the central station and Make timely and reasonable measures for a variety of unexpected situations to prevent disasters and reduce the damage caused by disasters.The design use the AT89C51 chip as the core, combined with the necessary peripheral circuits.We design the hydrological monitoring system with 51 MCU as a core. It consists of 12V DC power supply. On the hardware side, in addition to MCU, It uses SDI-12 bus to connect multiple sensors.Collected by TDC40(SDI-12 to RS232 converter) the water level sensor data is sent to the MCU ports PO.The MCU use FLASH to store real-time data and transport the collected water level data to the central station through communication channel, such as the PSTN, GSM, COMPASS satellite, maritime satellite and so on. On the software side, we use C language for programming. By programming on the MCU, we realize hydrological monitoring system for the entire hydrological data collection, storage and transport procedures for monitoring, to determine and control and human exchange.At the end, the paper gives an entire summary about the design and puts forward new prospects and views to provide a beneficial reference to the application used to signal acquisition, storage and transmission based on SDI-12 bus in the future.