DS1302 Real Time Clock Module

The DS1302 Real Time Clock Module keeps track of the time and date for your projects, even when the main power is switched off. Using a CR2032 backup battery (not included), it keeps counting seconds, minutes, hours, day, date, month, and year, with automatic leap-year compensation up to 2100, so your data loggers, clocks, and timers know the correct time after a restart.

The module uses a simple 3-wire serial interface (RST, I/O, and SCLK), so it needs just three signal pins plus power and ground. It supports both 12-hour and 24-hour formats and includes 31 bytes of battery-backed RAM for storing small amounts of data, such as settings or counters, that survive power loss. It runs on 2.0V to 5.5V and draws very little current in backup mode, so a coin cell can last a long time. It works with Arduino, ESP32, STM32, and Raspberry Pi through widely available libraries.

It is ideal for digital clocks, data loggers, alarm systems, attendance systems, and automatic timers. Whether you are a beginner learning about timekeeping or a maker building a time-stamped sensor logger, this compact module is a simple and affordable way to add real-time clock functionality.

Specification:

• RTC Chip : DS1302
• Timekeeping : Seconds, minutes, hours, day, date, month, year
• Calendar Range : Leap-year compensation up to 2100
• Time Format : 12-hour (AM/PM) or 24-hour
• Battery-Backed RAM : 31 bytes
• Interface : 3-wire serial (RST, I/O, SCLK)
• Operating Voltage : 2.0V to 5.5V DC
• Backup Battery : CR2032 (3V)
• Backup Current : Less than 300nA at 2.0V
• Operating Temperature : 0°C to 70°C
• Dimensions : Approx. 44mm x 23mm
• Package Includes : 1 x DS1302 Real Time Clock Module (CR2032 battery and jumper wires not included)