Design Of Wireless Temperature Measurement System Based On Internet Of Things

Temperature is of great importance in industry, agriculture and many life situations. For example, the rise of temperature of the linker in high voltage substations may cause fire, resulting in a large area of power grid equipment destroyed and causing great economic losses. The temperature and humidity in the granary affect the preservation of food. The greenhouse temperature changes affect the growth of plants. Therefore, it is particularly important to implement real-time monitoring of temperature in these situations.The Internet of Things is a new technology, and its research and application is ascendant. The Internet of Things is a network which connects any thing with Internet through the information sensing device, such as Radio-Frequency Identification (RFID), infrared sensors, global positioning system and laser scanning, according to agreed communication protocol. And its purpose is to achieve intelligent recognition, monitoring, object tracking, positioning and management of the object. The development of the Internet of Things technology provides another approach for real-time temperature measurement technology:using wireless sensor network technology for wireless temperature acquisition.In this thesis, wireless temperature measurement system is divided into temperature measurement station, temperature measurement terminal and temperature measurement nodes. Temperature measurement nodes acquire temperature data and transmit it to temperature measurement terminal through wireless way. Temperature measurement terminal transmits temperature data to temperature measurement workstation through RS485interface. Monitoring software of temperature measurement station save temperature data, and provide real-time, historical temperature curve drawing, data query, and the abnormal temperature alarm functions. Temperature measurement nodes are battery powered. Under the premise of ensuring system working normal and stable, to reduce the power consumption of the temperature measurement node will be able to extend the life of temperature measurement node, reduce the number of battery replacement and save human consumption. According to the requirements of low power consumption, this thesis consider from both hardware and software. In hardware design, this thesis compares several common short distance wireless communication technologies, and according to its advantages and disadvantages we select the radio frequency chip technology for wireless communication. The temperature measurement nodes adopt ultra-low power MSP430MCU, RF chip nRF905and DS18B20digital temperature sensor. In software design, we re-design the communication protocols, reducing the frequency of communication and data length according to the hardware structure. It can accomplish automatic network, channel selection, timing of temperature data acquisition, communication link of self-healing, and other functions. From two aspects of hardware and software, we detailed introduces the system design idea and principle of software design, hardware circuit structure and each part of the process.The wireless temperature measurement system based on the Internet of Things merits, they are:simple structure, high temperature measurement precision, fast response speed, small volume, easy to install, anti-interference ability, low consumption, low cost, and be able to better complete temperature acquisition and monitoring tasks.