 If you want to make your own electronic watch, an RTC module is necessary to generate you the right time, with very low power consumption.
 This tiny RTC module is based on the clock chip DS1307 which communicates with microcontrollers with I2C protocol. The clock/calendar provides seconds, minutes, hours, days, dates, months, and years information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. Besides, this module has really low power consumption, it can serve you for more than a month with a CR1220 battery.
Features:
- Connction Mode: I(IIC)
- Low Power Consumption, High Precision
- Dimensions(mm): 20.0 x 20.0 x 10.0
Package Included:
1 XÂ Crowtail-RTC
1 X Crowtail 4-Pin Cable
Gaithaingam Gonmei (verified owner) –
It is a nice and small RTC module based on DS1307 IC.
But it needs 5V to work properly (Not for 3.3V)
and it does not come with a coin battery (You need to buy a CR1220 3V Coin Battery)
Gaithaingam Gonmei –