Abstract:Aiming at the needs of smoke testing in urban rail transit, agriculture and other application fields, a smoke detection alarm based on the MQ-2 sensor is designed. The smoke detection alarm uses a single-chip microcomputer system STC89C51 as the core controller of the smoke detection alarm. It uses the gas sensor MQ-2 and DS18B20 temperature sensor to collect the smoke concentration and temperature signals in real time, and conducts analog signals with ADC0809 analog-to-digital converters. Mutual conversion between digital signals, and then input the converted digital quantity into the single-chip microcomputer (STC89C51), and the single-chip microcomputer (STC89C51) then inputs the smoke density, temperature and other digital quantities into the LCD1602 to realize real-time signal display. When the concentration or temperature of combustible gas in the environment exceeds the threshold set by the system, the smoke detection alarm will send out the corresponding light alarm signal and sound alarm signal to realize the intelligent reminder of the smoke alarm. The smoke detection alarm has the characteristics of short response time, good stability, high cost performance, and long life. It can be widely used in urban rail transit, agriculture and other fields.