DS1307 HW-111 real-time clock (RTC) Arduino module with CR2032 battery

DS1307 real-time clock (RTC) for Arduino, ESP8266, Raspberry Pi A precise real-time clock (RTC) module based on the popular DS1307 chip. The device is fully compatible with platforms such as Arduino, Raspberry Pi, ESP8266, and Banana Pi. The module is powered by a standard CR2032 battery at 5V. The integrated DS1307 works with additional 24C32 memory, enabling accurate timekeeping-seconds, minutes, hours, days, weeks, months, and years-including leap years. The module supports 12-hour (with AM/PM) or 24-hour mode. The clock uses an external 32.768 kHz quartz crystal and communicates with the microcontroller via the I2C bus. Its compact design and 3 mm mounting holes make installation easy in any electronics project. Component markings match the actual product photos. Key technical features

* Battery power: CR2032 5V

* Main chip: DS1307

* EEPROM memory: 24C32

* Crystal frequency: 32.768 kHz

* Communication interface: I2C

* Mounting holes: 3 mm diameter

* Dimensions: 27 x 27 x 10 mm

Example applications

* Data logging systems with precise timestamps

* Digital clocks and microcontroller-based weather stations

* Home automation systems that need time schedules

* Lighting controllers and irrigation systems with timer functions

* Alarm devices and access control systems

Benefits

* Continuous timekeeping: battery backup keeps the clock running even when main power is disconnected

* Versatility: simple I2C bus communication makes integration with many systems straightforward

* Extra memory: the built-in 24C32 chip allows storing small amounts of configuration data

* Compact size: the small board (27 x 27 mm) fits devices with limited space

* Easy mounting: dedicated mounting holes provide stable module fixation in an enclosure