可燃气体报警器的设计PROTEL99SE的原理图和PCB图，希望能对大家有一定的帮助。-Combustible gas alarm PROTEL99SE design the schematic and PCB maps for all of us hope to have some help.

烟雾传感器，内有电路图，搭配电压比较器可以实现数字输出，不接则为模拟输出-Smoke sensor, there are circuit diagrams, can be implemented with a voltage comparator digital output, analog output was not connected

大棚环境监测系统，esp8266 +AM2303+MQ-2 数据通过Android上位机接收，OLED本地显示传感器数据(The greenhouse environment monitoring system, the esp8266 +AM2303+MQ-2 data is received by the Android host computer, and the OLED local display sensor data)