The WeMos D1 R2 Uno based ESP8266 is a wireless 802.11 (Wifi) microcontroller development board is compatible with the Arduino IDE. It turns the very popular ESP8266 wireless (WiFi) module into a fully-fledged development board. The layout of this board is based on a standard Arduino hardware design with similar proportions to the Arduino Uno and Leonardo. It also includes a set of standard Arduino headers which means many existing Arduino shields can be plugged directly into the board.
The development board also includes a CH340 USB to serial interface giving it the ability to be connected and programmed directly from your computer and requiring only a common micro USB cable – no additional interface hardware or configuration is required. Once connected to the computer, and drivers have been installed, the WeMos D1 will appear as a standard serial COM port. The WeMos D1 can be programmed directly from the Arduino Integrated Development Environment.