What is the RTC Module ?
The RTC (Real-Time Clock) module is an electronic device that provides a clock to track and display the current date and time. It uses a battery as a power source to keep the time accurate even when the main power is turned off. RTC modules can be integrated with microcontrollers such as Arduino to keep track of time and date in projects such as calendars, clocks, data loggers, and other applications that require time-based functionality. The RTC module communicates with the microcontroller through I2C or SPI protocols.
There is a timekeeping board that contains a real-time clock and calendar. This board is a breakout module for the DS1302 chip and onboard a battery holder. It has a universal 32.768 kHz crystal oscillator.
You can connect and read data with 3-wire interface. DS1302 IC is a RTC module that is capable to hold seconds, minutes, hours, days, months, and years information continuously.
This product does not contain batteries. You need a CR2032 battery.
You can connect this module to nearly all microcontroller boards, for example, Arduino, Nodemcu, Raspberry Pi or etc.
Small Tip for Makers: DS1302 communication is not I2C, SPI, or One Wire Protocol. Because of that, you should use Arduino playground page : https://playground.arduino.cc/Main/DS1302/