A design of wireless temperature and humidity monitoring system

The existing data sampling schemes can not update ROM serial numbers of DS18B20 automatically and locate DS18B20s accurately. For these reasons above, it is difficult to replace the faulty DS18B20s immediately. To solve this problem, both I/O (Input/Output) ports number of MCU (Micro Controller Unit) and the value of temperature alarm trigger registers (TH and TL) are used to determine the storage address of ROM serial numbers in 24LC256, and are also used to adopted as the physical address of DS18B20. Consequently, automatic updating of ROM (Read Only Memory) serial numbers and exactly locating of the temperature data can be completed. Meanwhile, to reduce the cost and avoid complex network cabling in wired network, a distributed wireless tempreature and humidity monitoring system based on MCU and wireless networking is proposed.