The Design And Implementation Of Data Acquisition And Transmission System Based On Passive Sensor

With the development of wireless sensor network, it brings the change of information acquisition mode in the world, and makes the research and application of sensor network more and more widely. The passive wireless sensor as a new type of sensor, it has the characteristics of extremely strong environment adaptability, independent power supply and high reliability. Therefore, it is especially suitable for applications in some harsh environment, which cannot provide reliable power at the scene and cannot directly supply power for the sensor nodes. It becomes one of the hot issues in the current study, which has been applied in the fields of temperature, humidity, pressure and so on. Data acquisition and transmission based on passive sensor is one of the most important parts, the thesis around with the National 863 project "passive wireless multi parameter micro nano sensor and system", it focuses on the research and design of data acquisition and transmission system based on temperature, humidity and pressure passive sensor.Firstly, the thesis analyze the functional requirements of the system combined with the application demonstration scenario, then the data acquisition and transmission scheme based on passive wireless sensor is designed, which is suitable for application-environment.Because the passive sensor has the characteristics of temperature, humidity and pressure parameters of three hybrid packaging output and power supply be made one, according to the signal characteristic of digital frequency the multi parameter outputs, the scheme on how to separate and accurately read the sensor data is designed.Secondly, due to the practical application scenarios is the workshop environment of 200*200m2 multi metal obstacles, the design with Bluetooth, WiFi or even ZigBee is difficult. The characteristic of 2.4G band with weak diffraction ability brings Multi-Routing, high-cost, high power consumption and other issues, the most suitable wireless transmission scheme is designed for the environment. In view of the above requirements, this thesis mainly focuses on the scheme of data acquisition based on STC89C52 timing counting principle and the wireless transmission scheme based on 433M frequency in order to obtain the information of the sensor and realize wireless data transmission. On the basis of theoretical analysis, The hardware and software of the whole system is designed, hardware circuit design mainly includes power circuit design, USB transfer TTL circuit design, data acquisition circuit design and wireless transmission circuit design; The software design includes underlying data acquisition, wireless transmission and PC. The design of the whole data acquisition and transmission system is simple.At last, the experiment test of the design system is been done. The software and hardware platform are set up, the reliability of the system is evaluated based on the experiment results, the practicability of the data acquisition and transmission system designed in this thesis is verified.