According to the characteristics of the library of environmental monitoring,this paper designed a building environment monitoring system based on WiFi.The sensor nodes use the STM32 processor to carry various environmental sensors and ESP8266 WiFi modules.The AP+STA mode of the module not only makes the node as terminal,but also a router.The processor sends control instructions to the WiFi module or receives data from the module and takes charge of encoding the environment parameters detected by various sen...