Operating temperature: -40 to 125 degree Celsius.Features of NodeMCU ESP-12E development board So, you do not need any external programmer to program this board and you can easily run this board directly on 5V from USB. The ESP-12E comes with a programmer and a 3.3v SMPS unit. It has 2.4 GHz Wi-Fi that supports WPA/WP2. The module that runs this firmware is ESP-12E and that module is based on 32-bit ESP8266 MCU. It is an open-source Lua-based firmware that is designed for IoT(Internet of Things) applications. NodeMCU stands for Node Microcontroller Unit.
