Abstract
The quality of the environment depends on many factors, such as temperature, humidity, smoke particles, carbon dioxide concentration, and so on. For hotels, smoke detection is sure the most important establishment among others. It is because that smoke detection is directly related to the safety of the hotel and the guests. This is the most important content of the system. In addititon , temperature and humidity monitoring have been introducted in the system.
The system uses temperature and humidity sensor SHT11 and smoke sensor MQ-N5 to collect data. SHT11 is a digital sensor with highly integrated inner system and anti-jamming capacity, which makes the collected signal more precise. The integrated I2C bus interface is a sensor, which can directly connect with any type of microprocessor and microcontroller system, it is very simple and practical.
The entire system works under DC Regulator of five voltages .The client computer consists of Signal acquisition module 、Smoke alarm module and RS-232 and RS-485 conversion module. After setting the Communication Protocol of RS-485 bus ,the master computer can cloose any of the client computers and make the communication with the right-time .The final effect of the entire system is
relatively good, and has the faster response the measurement is also comparatively accurate, it still has a certain relevance and application prospects.
Key Words: sensor; RS-232 and RS-485 conversion circuits; RS-485 bus
