"基于单片机的智能环境监测系统：温湿度、烟雾和人体检测"

Abstract: The intelligent environmental monitoring system based on single-chip microcomputer is designed with modules including temperature and humidity detection, smoke detection circuit, alarm circuit, display circuit, and human body detection. The DHT11 temperature and humidity sensor is used in the temperature and humidity detection part. DHT11 is a single-bus digital temperature and humidity sensor with features such as small error, high resolution, and strong anti-interference ability. In the smoke detection circuit module, the basic functions are achieved using the gas sensor MQ-2 and ADC0832 analog-to-digital converter. With these sensors and chips, the system will emit corresponding light and sound alarm signals when there is a change in combustible gas concentration or toxic gas in the environment, achieving fire alarm and intelligent prompt. The human body detection part is implemented through the HC-SR501 module, which converts the sensed infrared thermal radiation signal into an electrical signal, amplifies it, and outputs it. If a danger signal is detected, the signal will be transmitted to the single-chip microcomputer, processed by the microcontroller, and then control the buzzer and LED to sound the alarm. This design can also be applied in various anti-theft scenarios, such as home anti-theft and warehouse anti-theft. Temperature, humidity, smoke, and human body anti-theft detection are the three most basic environmental parameters, and their measurement methods and devices are of great significance to current life and production. Keywords: temperature and humidity detection; MQ-2 sensor; smoke alarm; passive infrared sensor; anti-theft alarm.