[Resource Download] The download address is as follows:
https://docs.qq.com/doc/DTlRSd01BZXNpRUxl
51 Indoor Detection System Design-DHT11-Bluetooth-LCD1602-BELL-MQ-9-PCF8591-Fan
This design consists of STC89C52 single-chip circuit + DHT11 temperature and humidity sensor circuit + Bluetooth module circuit + LCD1602 liquid crystal display circuit + buzzer alarm circuit + methane detection circuit + AD_PCF8591 conversion circuit + fan circuit + power supply circuit.
1. LCD1602 liquid crystal display real-time methane concentration, temperature and humidity.
2. When the methane concentration or temperature or humidity is greater than the set value (the specific set value is determined by Tongwang Technology), the buzzer will alarm.
Otherwise, the buzzer will not alarm.
3. Send the methane concentration, temperature and humidity to the mobile APP through the Bluetooth module.
4. The start and stop of the fan can be controlled through the mobile phone APP.
Bluetooth commands:
*//Turn on the fan
#//Turn off the fan
