Research And Realization Of A Universal Wireless Sensor Interface Based On BLE 4.0

The Internet of Things(Io T)is a major development and change opportunity in the information field.The application of Io T has made great contribution to social development,which is an important opportunity for various industries to modernize.With the rapid development of the sensor technology,communication technology and cloud computing,wireless sensor networks(WSN)has a wide application prospect in military application,agricultural production,medical testing and intelligent city.With the rapid development of WSN,the openness and interoperability of sensor in perception layer are increasingly demanding.At present,sensors in WSN don't have a unified interface,the output signal types,data formats and interactive protocols are also different,leading to the sensor from different manufacturers are not compatible with each other,system expansion and maintenance is very difficult.Therefore,it is very important to carry on the unified standardized design to the sensor interface in WSN.In this paper,WSN node sensor signal processing and data transmission are discussed,a universal wireless sensor interface(USI)based on bluetooth low energy is presented.The B-USI can realize the sensor plug-and-play,environmental information collection,wireless data transmission and display.The main contents are as follows:(1)Proposed the interface design scheme based on bluetooth 4.0.Combining with the rapid development of Io T and WSN,this paper analyzes the research status and existing problems of USI at home and abroad;The key issues of USI design are analyzed,including standardization of signal interface,the design of power supply,and the choice of transmission technology.After comparing three kinds of wireless transmission technology Zig Bee,Wi-Fi,Bluetooth,the interface scheme based on bluetooth 4.0 is proposed.(2)Design interface hardware based on Nordic's n RF51822 EK platform.Design the signal interface circuit using the principle of modularity,which can handle current,voltage,switch and serial signal.Follow-up to do further functional expansion,increase I2 C,SPI,USB and other circuits.(3)According to the interface design proposed in this paper,software is written to realize the wireless communication between the universal interface and android mobile phone.Design the communication protocol between common interface and android mobile phone.Using C language to write the embedded code of interface.Using Java and XML language to develop the android application for the interactive interface,sampling channel selection,interface parameters setting and other functions.Complete the testing of B-USI.According to the content of this paper,the optimization aspects,including the expansion of interface circuit,optimization of network topology and protocol upgrade,cloud computing analysis of the sensor data and the next research direction.