The design of temperature measurement system based on STM32 platform
|Course||Electronics and Communication Engineering|
|Keywords||non-contact measurement of the temperature STM32platform star network communication protocol|
At present, there are many kinds of method of temperature measurement, they mainly can bedivided into two ways, contact temperature measurement and non-contact temperature measurement.Although contact temperature measurement has a relatively high accuracy, can measure environmenttemperature and the temperature of each part of the object to be detected, but for measuring thetemperature of the liquid in the bottle to be detected, especially in cases of fast, accurate, and no-openbottles, this method is not suitable. That is to say, we need to adopt a method to measure objecttemperature without contacting it.Therefore, this design uses the infrared temperature measurement which is one of the importantnon-contact temperature measuring method. It takes advantage of the principle of the higher thetemperature of the object, the more infrared radiation comes out, the stronger the infrared radiationenergy to realize the non-contact temperature measurement. So we can use the value of liquid radiantenergy to judge its’ temperature without opening the bottle. At the same time, considering the highpower and calorific value of microwave platforms, if its temperature is too high, it will affect the properfunction of the platform. So the real-time monitoring of microwave platform temperature is necessary,using non-contact temperature measurement can achieve this requirement.This design completed a wireless temperature measurement system based on STM32platformconstruction, and completed the system hardware and software design, realized fast and accuratetemperature measurement of the microwave platform and the liquid inside bottles. system adopts ARMchip STM32F103VCT6as the main control chip, several DS18B20digital temperature sensor, whichprecision can reach0.5℃, to achieve one-line type multipoint temperature measurement of themicrowave platform,and uses MLX90614infrared temperature sensor to conduct non-contactmeasurement of temperature of the liquid inside bottles. After temperature compensation, precision canreach0.5℃, meeting the design requirements of measurement accuracy. According to the basicprinciple of infrared temperature measurement and sensor characteristic，we put forward the main errorsources of infrared measuring temperature of liquid in the bottle should include the distance betweenthe bottle and infrared sensor, the material of the bottle and the shape of the bottle. Then, using thedesigned temperature measurement platform，we collected a large number of temperature data, and after analysis and calculation，we verified the source of errors. According to the size of the error, weput forward the best working conditions for MLX90614infrared temperature sensor and completed thedesign of temperature compensation，which is of important reference value and significance for thefollow-up research and development. Finally, the design chooses five pieces of2.4G wirelesscommunication module nRF24L01formed an indoors star network，which contains a host and fourslaves from machine line. The communication between them are implemented through the self-definedcommunication protocol, the protocol includes two parts，upward and downward agreement, the mainachievement of the protocol is that host machine can query slave states and send control commands，slaves can send temperature data to the host. Actual debugging proves that self-organized networkconnection is normal and data communication is reliable and stability, achieving the wireless datatransmission function of star networks.