The Design Of Real-time Monitoring System For Temperature And Humidity

This paper introduces a kind of real-time monitoring system for temperature and humidity controlled by computer, which is can be used for many applications. The paper completes both the software and hardware design. The system adopts 1-Wire sensor net and RS485 transmission net technique. Many sensors are connected to 1-Wire bus as intelligent terminals. The data collection station gathers all buses. Each data collector is responsible for a region. The kernel of data collector is MCU, which takes charge of measurement, control and communication with the host controller. The RS485 transmission net is made up of the data collection station, which can transmit for remote distance and restrain common mode interference. The RS232/RS485 converter is used for conversion between RS485 and RS232, which is used by the host controller, computer. A self-contained serial communication protocol is defined, which can help the host controller communicate with the data collector. The host controller works as a dispatcher. CRC technology is adopted to verify data and guarantee the dependability in the communication. The Delphi is used to design the user interface for display and monitoring of temperature and humidity information, showing and printing for historical records and curves etc.