D1 Mini Development Board

The development board is based on the WiFi-SoC ESP8266 and is made for fast Internet-of-Things (IoT) prototyping. It is flashed with the NodeMCU firmware and can be set up and programmed right away with the on-board microUSB connection. With only few lines of code the NodeMCU Dev Kit is connected to your local network and ready to be controlled by other network members like computers and smartphones. The D1 mini is a mini wifi board based on ESP-8266EX.

Features:

11 digital input/output pins, all pins have interrupt/pwm/I2C/one-wire supported(except D0)
1 analog input (3.3V max input)
A Micro USB connection
Check out the sample Lua commands on the:  https://github.com/nodemcu/nodemcu-firmware
Compatible with: https://github.com/esp8266/Arduino
Compatible with: http://nodemcu.com/index_en.html