Two can't put it down and connect here
ESP32-A1S WiFi and Bluetooth Module ESP32 serial to WiFi Audio Module ESP8266 4MB FLASH ESP-12S Chip Board USD 3.5 / piece /lot 1
ESP32 ESP-32S Module ESP3212 ESP32-Bit Bluetooth 4.2 Wifi Module Support Linux Window Dual-core Processor Module USD 4.11 / piece /lot 1
ESP8266-12E Is an enhanced version ESP8266-12 , improve the external circuit, enhanced impedance signal output is better, whether it is stable or anti-jamming capability , have been greatly improved ! Before selecting a user for ESP-12 's , it does not matter even if the product has been made , enhanced version is fully compatible with previous firmware pin has added the ESP-12 on the basis of six IO ports , SPI mouth leads , develop more convenient, application more extensive !
