https://escapequotes.net/esp8266-wemos-d1-mini-pins-and-diagram/
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 GP
escapequotes.net
Pin
PinFunctionESP-8266 PinRXRXDRXDD0IOGPIO16D2IO, SDAGPIO4D4IO, 10k pull-up, BUILTIN_LEDGPIO2D6IO, MISOGPIO12D8IO,10k pull-down, SSGPIO155V5V–RSTResetRST
| TX | TXD | TXD |
| A0 | Analog input, max 3.3V input | A0 |
| D1 | IO, SCL | GPIO5 |
| D3 | IO,10k Pull-up | GPIO0 |
| D5 | IO, SCK | GPIO14 |
| D7 | IO, MOSI | GPIO13 |
| G | Ground | GND |
| 3V3 | 3.3V | 3.3V |
*All IO have interrupt/pwm/I2C/one-wire supported(except D0)
d1 mini shematics (updated schematics):
http://www.wemos.cc/en/latest/_static/files/sch_d1_mini_v3.0.0.pdf
Programming
The D1 mini has a micro USB for auto programming. Also you can programming it using OTA
Warnings
All IO is work at 3.3V.
Source wemos.cc