Research On Ultrasound Water Meter Based On NB-IoT Technology

With the rapid development of science and technology and information technology industry,water meters which are closely related to our lives are constantly updated and replaced.Ultrasound water meters are widely used because of their non-contact measurement,wide application range,high accuracy,intelligence,low cost,easy installation and maintenance,etc.Traditional mechanical water meters can not meet the needs of social development and are gradually replaced.Ultrasound water meter commonly used temperature sensors to measure temperature compensation,high cost and complex structure.In this paper,with little impact on measurement accuracy,temperature compensation is realized by using look-up table method,which reduces hardware,simplifies structure and reduces the overall cost.Traditional manual meter reading requires staff to collect water meter data door-to-door,which not only costs a lot of labor and workload,but also fails to reflect the user’s use situation in time.Although wired meter reading solves some problems of manual meter reading,it needs to lay a large number of cables,which is not only costly,difficult to maintain in the later period,but also vulnerable to weather and power grid.The normal operation of meter reading system has been seriously affected.With the development of Internet of Things,wireless meter reading mode is used more and more.NB-IoT(Narrow Band Internet of Things)is a new technology of Internet of Things.It has the characteristics of wide coverage,low power consumption,low cost,Dalian connection,using operator’s authorized frequency band,without the support of intermediate hardware and software.Compared with other wireless meter reading methods,NB-IoT has advantages.Obviously,more and more applications.Therefore,this paper designs an ultrasonic water meter based on NB-IoT technology.The hardware of the system consists of an ultrasonic water meter and a NB-IoT module.Among them,the 16-bit ultra-low power single-chip MSP430F4152 of TI company is selected as the main control chip,the U-type installation mode of the ultrasonic transducer is selected,and the high-precision time conversion chip TDC-GP21 is selected to complete the measurement of the time of the ultrasonic wave propagating in the fluid,and the temperature is compensated by looking up the table method according to the time of the forward and backward flow,and the fluid flow is calculated by time difference method.Then the flow rate of the fluid is calculated,and the cumulative flow rate is displayed by LCD.Ultrasound water meter contains NB-IoT wireless transmission module BC95-B8 based on NB-IoT technology.The microcontroller transmits information such as cumulative flow to the module through serial port.The module transmits data to IoT(Internet of Things)cloud platform regularly through operator base station,and checks water consumption of ultrasonic water meter in real time through cloud platform.After experimental verification and overall testing,the ultrasonic water designed in this subject is expressed in the national application standard.Through NB-IoT wireless transmission module,the MCU and IoT cloud platform can communicate normally and stably,and the data transmission is timely and effective,which achieves the expected standard.