Design Of Low Cost Wireless Meteorological Fax Receiving And Display Control System

With the continuous exploration and development of the ocean,there is a growing demand for meteorological information for large ships.Meteorological information is widely used in military,trade and daily fields,which is an important guarantee for the safe navigation of ships.Therefore,meteorological fax machines are widely used in large ships to obtain meteorological information needed for navigation.At present,most meteorological fax machine systems in China are large in volume,low in system integration,complex in operation methods,and inconvenient to collect and view images.With the continuous progress of embedded technology,a simple structure and convenient operation are developed.A variety of meteorological facsimile systems are possible.Based on the existing facsimile technology,a new meteorological facsimile receiving and display control system is studied in this paper,which combines the meteorological facsimile machine with the upper computer in the way of network interface.The user controls the meteorological fax machine by operating the upper computer and displays the received fax images in the man-machine interface.The system is divided into two parts: shortwave signal receiving board,data processing board and control board.According to the communication principle of RF signal,the analog circuit of two-stage superheterodyne structure is designed.The data processing and control board sample the FSK signal output from the front-end board,and demodulate the sampled data by software.Then the data is transferred to another core by sharing RAM between two cores,and then the received data generating image file is saved to the external memory.The meteorological fax machine interacts with the host computer through the Ethernet interface.The user controls the fax machine system in the man-machine interface to receive the meteorological facsimile map and upload the image to the upper computer for viewing.Among them,the facsimile receiving mode includes manual receiving and timing receiving.The communication principle of meteorological fax machine is analyzed in this paper.On the basis of this,the circuit schematic diagram is designed,each module is explained in detail,and the corresponding software scheme is designed,and the software flow chart is given.Then the function modules are debugged and verified.Finally,the system is combined to realize the function of receiving meteorological facsimile images.This design simplifies the structure of fax machine,reduces the cost of system development and improves the processing speed of meteorological fax data.