This is ESP8266 12E Serial Port WIFI Wireless Transceiver Module For Arduino. This small WIFI transceiver is the perfect solution for home Automation and IoT applications. It can be the replacement of your NRF24L01, it can talk to your WIFI router directly through the UART MCU’s (Rx, Tx).
The ESP-12 module is one of the most complete of the ESP family as it allows you to use the biggest amount of pins of all of them. You can program this module to work stand alone with the Arduino IDE or with LUA as NodeMCU.
It has an LDR and a WS2812 led already on board for your projects. The board comes with a CH40 micro USB module to program it. The ESP8266 highly integrated chip, including antenna switch balun, power management converter, so with minimal external circuitry.
The system is equipped with ESP8266 manifested leading features are: energy saving VoIP quickly switch between the sleep/wake patterns, with low-power operation adaptive radio bias, front-end signal processing functions.
The ESP8266-03 is one of the smallest versions of this module. It includes a built-in ceramic antenna.
1 x ESP8266 12E Serial Port WIFI Wireless Transceiver Module for Arduino