一种基于AT89C52的自动雨量站的研制

在超声探头(5P14)上施加一负电压脉冲信号，探头发出脉冲超声波，当遇到不同介质界面的时候超声波被反射，回波信号被超声探头接收，转换成脉；中电压信号，利用AT89C52单片机的捕捉功能来计算超声波回波与发射波之间的时间，进而计算出超声波在液体中传播的时间；利用数字温度计DSl820采集温度信号，用该信号可准确计算超声波的传播速度，实现对液位的精确测量。测量误差小于0．1mm(雨量小于10mm时)，优于0．5％(雨量大于10mm时).

Development a kind of auto raindrop detecting set base on AT89C52

The ultrasonic detector (5P14) gives off an ultrasonic wave when it is given an electronic pulse. This ultrasonic wave is rejected at the interface of two kinds of media. The ultrasonic detector receives this wave and converts it into electronic pulse. The time between the send pulse and the back pulse can be captured using the capture function of the MCU AT89C52. The temperature can be got by the digital temperature sensor DS1820. Use the temperature, the speed of ultrasonic can be calculated accurately and the height of liquid can be measured accurately. The absolute error of measure is limited within 0.1mm when the precipitation rain fall is less than 10mm and the relative error is limited within 0.5% when the precipitation rain fall is more than 10mm.