The Pi RTC (real-time clock) is based on the clock chip DS1307, providing a real-time clock for the Raspberry Pi via the I2C interface. The real-time clock of this module counts seconds, minutes, hours, dates of the month, month, day of the week, and year with leap-year compensation valid up to 2100.

If you want to keep this module timing when the Raspberry Pi is powered off, you need to put a 3-Volt CR1225 lithium cell in the battery holder.

Highlighted Features

• The clock operates in either the 24-hour or 12-hour format with AM/PM indicator
• 24-hour or 12-hour formats with AM/PM indicator
• Supporting seconds, minutes, hours, days, weeks, months and year
• Automatic power-fail detect and switch circuit
  
• A programmable square wave output signal
• This product is typically used for real-time clock applications, such as GPS and telematics

Specifications

• Supports Raspberry Pi 2/3 B/B+ Zero/4
• Operating Voltage: 5v
• I2C Interface
  
• I2C Address 0x68
  
• 56-byte, battery-backed, nonvolatile (NV) RAM for data storage

Hardware Overview