The popular Raspberry Pi computer unfortunately lacks a real time clock. This is a high precision Real Time Clock (RTC) module for the Raspberry Pi, either Model A or Model B. Designed to connect directly to the Raspberry Pi GPIO port with an ultra small footprint.
The DS3231 is a low-cost, extremely accurate I2C real- time clock (RTC) with an integrated temperature- compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input, and maintains accu- rate timekeeping when main power to the device is inter- rupted. The integration of the crystal resonator enhances the long-term accuracy of the device as well as reduces the piece-part count in a manufacturing line. The DS3231 is available in commercial and industrial temperature ranges, and is offered in a 16-pin, 300mil SO package.
The RTC maintains seconds, minutes, hours, day, date, month, and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with an AM/PM indicator. Two programmable time-of- day alarms and a programmable square-wave output are provided. Address and data are transferred serially through an I2C bidirectional bus.
- Accuracy ±2ppm from 0°C to +40°C
- Accuracy ±3.5ppm from -40°C to +85°C
- Battery Backup Input for Continuous Timekeeping
- Operating Temperature Ranges - Commercial: 0°C to +70°C, Industrial: -40°C to +85°C
- Low-Power Consumption
- Real-Time Clock Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation Valid Up to 2100
- Two Time-of-Day Alarms
- Programmable Square-Wave Output
- Fast (400kHz) I2C Interface
- 3.3V Operation
- Digital Temp Sensor Output: ±3°C Accuracy
- Register for Aging Trim
- RST Output/Pushbutton Reset Debounce Input
- Underwriters Laboratories (UL) Recognized
Check out the blog post here on how to use it with Raspbian on a Raspberry Pi.