1. NodeMCU

What is NodeMCU?

The NodeMCU (Node MicroController Unit) is an open source software and hardware development environment that is built around a very inexpensive System-on-a-Chip (SoC) called the ESP8266. The ESP8266, designed and manufactured by Espressif Systems, contains all crucial elements of the modern computer: CPU, RAM, networking (wifi), and even a modern operating system and SDK. When purchased at bulk, the ESP8266 chip costs only $2 USD a piece. That makes it an excellent choice for Internet of Things projects of all kinds.

Through its pins we can read inputs - light on a sensor, a finger on a button, or a Twitter message -and turn them into an output - activating a motor, turning on an LED, publishing something online. It has also WiFi capabilities, so we can control it wirelessly and make it work on a remote installation easily! We can tell our board what to do by sending a set of instructions to the microcontroller on the board. To do so we can use the the Arduino Software (IDE).

Assuming we have already installed the ESP8266 support on our Arduino IDE (following the instructions on Installing with Boards Manager ), we choose the right port from the Ports menu and the NodeMCU 1.0 (ESP-12E Module) from the Boards menu.