DS1307 RTC Module

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Overview

The DS1307 RTC module basically is a time-tracking device that gives the current information and time. RT means Real-Time Clock. They make the RTC module with clock chip DS1307. We generally need this module in computers, laptops, or any other embedded systems or devices to provide time and date. RTC module functions on the I2C protocol. The module provides information like an hour, minute, second, day, year, etc. One can use it with any of the formats, either 24hr or 12hr.

Hardware Overview

  • RTC chip: At the center of the module there is a low-cost RTC chip DS1307. It deals with all timekeeping functions and features.
  • SQW pin: This module board comes with an SQW pin, which yields one of four frequencies (1Hz, 4kHz, 8kHz, or 32kHz) of square waves. This can be enabled through programming.
  • EEPROM chip: DS1307 module also has a 32 bytes 24C32 EEPROM chip with limited read-write cycles. It can save settings. It I2C interface for communication 
  • Battery Holder: There is a CR2032 battery with a capacity 47mAh.

Features and Specifications of DS1307 RTC Module

Features

  • Available in 8-pin DIP or SOIC
  • Underwriters Laboratory (UL) recognized
  • Real-time clock (RTC) counts seconds, minutes, hours, dates of the month, month, day of the week, and year with leap-year compensation valid up to 2100
  • 56-byte non-volatile RAM for data storage
  • Two-wire interface (I2C)
  • Completely Manages All Timekeeping Functions
  • Programmable Square-Wave Output Signal
  • Simple Serial Port Interfaces to Most Microcontrollers
  • I2C Serial Interface
  • Low Power Operation Extends Battery Backup Run Time
  • Consumes Less than 500nA in Battery-Backup Mode with Oscillator Running
  • Automatic Power-Fail Detect and Switch Circuitry

Specifications

Range of Operating Voltage3.3V – 5V
Typical voltage supply5V
Real-Time lock chipDS1307 I2C
EEPROM ChipAT24C32 32K I2C EEPROM memory
Battery typeLIR2032 rechargeable lithium battery
Power consumptionIt operated on a battery then it consumes less than 500 nA of power.
Clock ProvideHour, Minutes, Seconds, AM/PM.
Calendar providesDay, Date, Month, Year.
PCB Size27mm * 28mm * 8.4mm (L*W*H)

Pinouts of DS1307 RTC Module

Pin NameDescription
SQWThe SQW pin has a cool feature, it can produce outputs one of four square-wave frequencies 1 Hz, 4 kHz, 8 kHz, or 32 kHz, and can be possible programmatically.
DSThis pin is used to read Output from the DS18B20 temperature sensor if the RTC module has a DS18B20 temperature sensor installed.
SCLThis is a clock-input I2C serial communication pin. It is used to synchronize data movement on the serial interface.
SDAWe use this pin for the data input/output for the I2C serial interface.
VCCIt is a positive power input pin of the module in the range of 3.3V to 5.5V.
GNDGND is a negative(ground) power input pin
BATBAT pin is a backup supply input for any standard 3V lithium cell or other energy sources to maintain accurate timekeeping when the main power to the device is interrupted.

Applications of RTC Module

Digital Clocks

The real-time digital clocks present information about the hours, months, dates, years, etc, and can be operated in 24hr or 12 hr format with an indicator of AM and PM. Hence. it can employ this RTC module to serve the purpose.

Computers, Smartphones, etc

To get information about real-time data, computers, laptops, and smartphones circuits can adopt this module.