To link a standard 16×2 LCD directly with the microcontroller, for instance Arduino, you would need atleast 6 I/O pins to talk to the LCD. However, if you use an LCD module with I2C interface ... This ...

The Arduino ... I2C module to convert your LCD into an I2C device (so it uses fewer pins), a motor driver for your fan, a breadboard to hold the components together, and some jumper wires for ...

The Arduino Uno Rev3 is the third revision ... and R4 WiFi is the number of their serial ports and I2C buses. The Rev3 has a single serial connection, shared by the USB port and the RX/TX pins.