The Wemos D1 mini is a mini wifi board with 4MB flash memory based on ESP-8266 EX.
It is Arduino compatible, that means we can flash Arduino firmware on it and program it like an Arduino board.
It is also possible to flash other firmware on it, like NodeMCU.
Learn more https://wiki.wemos.cc/products:d1:d1_mini
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 |
| D5 | IO, SCK | GPIO14 |
| D6 | IO, MISO | GPIO12 |
| D7 | IO, MOSI | GPIO13 |
| D8 | IO, 10k Pull-down, SS | GPIO15 |
| G | Ground | GND |
| 5V | 5V | - |
| 3V3 | 3.3V | 3.3V |
| RST | Reset | RST |
Mac OS
Source: https://blog.sengotta.net/signed-mac-os-driver-for-winchiphead-ch340-serial-bridge/
USB to Serial driver for Mac OS:
If the Arduino IDE doesn't show the board after installing. Try copying the usbserial kext /Library/Extensions/usbserial.kext to /System/Library/Extensions.