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, you only need 2 lines to process the display information. Now a days, ...

The core of the watch is an Arduino Mini. To make it good for time telling, a real-time clock module was added. A DHT11 monitors the ... and other data with an LCD from a Nokia 5110.