The Design of Automatic Temperature and Humidity Recorder

Abstract

Aiming at the problems that the traditional temperature and humidity recording manual operation is low efficiency, put forward a design scheme of temperature and humidity automatic alarm recorder. real-time monitor temperature and humidity sensors using single chip microcomputer technology, after the data is collected and processed, the results is displayed on the LCD screen, at the same time, transmit the data to PC for display through the RS485 serial communication, also The design has the function of data record and historical data inquiry, the host computer remote control and so on, when temperature and humidity exceeds user-set upper and lower limits, the device will automatically alarm. Introduction Temperature and humidity measurement is an important part of the modern detection technology, in order to ensure the quality of the products, saving energy and safety production and plays a key role. Therefore, to ensure fast and accurately measuring technology and device for temperature and humidity generally by various countries attention. With the development of communications technology and computer technology, temperature and humidity measurement technology in Japan, Netherlands, United States, Israel and other developed countries has been rapid developed. Now foreign temperature and humidity measurement technology is moving towards the development of high-tech direction, Network technology, remote sensing technology has been gradually integrated with the production activities. In recent years, China has also increased the research efforts in the temperature and humidity measurement technology, Despite advances in technology, more humane, but there is not remote control the working status of the equipment. This design in the original technical level, has made the further improvement: 1, environmental parameters data processing with higher accuracy requirements, ensure the goods in storage environment, increase the economic efficiency of enterprises; 2, using low power components, the power consumption will be greatly reduced, reducing the power consumption cost; 3, the adjustment of environment monitoring technology, not only can observed the data in the main equipment on the site, but also observation the data in any PC equipped with corresponding PC machine, The parameters of the main equipment, set command to complete the monitoring and control of the combined, largely reduce manpower participation process. Overall System Design The system is mainly composed of three parts, data acquisition device, control center, host computer .( the overall design diagram of the system see Fig. 1). 2016 6th International Conference on Applied Science, Engineering and Technology (ICASET 2016) © 2016. The authors Published by Atlantis Press 0082 Fig.1 the overall design of the system Controlled by MCU, the data acquisition terminal using temperature and humidity sensor AM2321 to temperature and humidity data real-time acquisition and the collected data were processed and displayed on the LCD screen, also through the RS485 serial communication would be processed by the data to PC display, when the temperature and humidity exceeds the setting upper and lower limit, the alarm device will be activated. Hardware Design The circuit design of data acquisition terminal Fig.2 The system block diagram in figure 2 data acquisition Mainly use the high precision temperature sensor, capacitive humidity sensing element, A/D converter, signal amplifier and a high performance embedded microcontroller integrated consisting of AM2321 temperature and humidity sensor to achieve the data collection. Through the amplifier to collect the data signal stronger than normal, and the conversion of the collected data through the A/D converter in a timely manner, so that the output digital signal is more anti-interference . Data acquisition in the system block diagram as shown in Fig. 2, the smallest system consists of DC/DC voltage stabilizer, reset circuit, MSP430, crystals circuit structure, etc. Data display and alarm circuit design The MSP430 as control center processor, using 2.8 inch alientek TFTLCD liquid crystal module as the display unit, the control center alarm and prompt the user through the buzzer, the NPN triode 8050 as alarm circuit switch, when beep is a 3.3V high level,after the voltage division, the base Power supply module