Programming your D1mini ESP8266 in ArduinoIDE: use Arduino IDE 1.6.5 check your aditional board URL from file->preferences http://arduino.esp8266.com/stable/package_esp8266com_index.json check D1 mini board The actual pins on the board: Pin Function ESP-8266 Pin TX TXD TXD RX RXD RXD A0 Analog
WeMos D1 mini ESP8266
The D1 mini is a mini wifi board based on ESP-8266EX from WeMos.cc.