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 pins and diagram
Diagram Pin Pin Function ESP-8266 Pin TX TXD TXD RX RXD RXD A0 Analog input, max 3.3V input A0 D0 IO GPIO16 D1 IO, SCL GPIO5 D2 IO, SDA GPIO4 D3 IO,10k Pull-up GPIO0 D4 IO, 10k pull-up, BUILTIN_LED GPIO2
WeMos D1 mini ESP8266
The D1 mini is a mini wifi board based on ESP-8266EX from WeMos.cc.