DS3231 Real time clock + AT24C32 Module IIC

• 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,  disconnect the main power supply and maintains accurate timekeeping.
• Integrated oscillator improve long-term accuracy  of the device and reduces the number of components of the production line.
• DS3231 available in commercial and industrial  temperature ranges, using a 16-pin 300mil SO package.
• RTC maintains seconds, minutes, hours, day, date,  month, and year information. Less than 31 days of the month, the end date will  be automatically adjusted, including corrections for leap year.
• Clock operates in either the 24 hours or band / AM  / PM indication of the 12-hour format. Provides two configurable alarm clock and  a calendar can be set to a square wave output.
• Address and data are transferred serially through  an I2C bidirectional bus.
• A precision temperature-compensated voltage  reference and comparator circuit monitors the status of VCC to detect power  failures, provide a reset output, and if necessary, automatically switch to the  backup power supply. 
• /RST pin is monitored as generating μP reset  manually.
• Save time and high precision addition, DS3231 also  has some other features that extend the system host of additional features and a  range of options.
• The device integrates a very precise digital  temperature sensor, through the I2C * interface to access it (as the same time).
• Temperature sensor accuracy is ± 3 ° C. On-chip  power supply control circuit can automatically detect and manage the main and  standby power (i.e., low-voltage battery) to switch between the power supply.
• If the main power failure, the device can continue  to provide accurate timing and temperature, performance is not affected.
• When the main power re-power or voltage value  returns to within the allowable range, the on-chip reset function can be used to  restart the system microprocessor.

Module parameters:

• Size: 38mm (length) * 22mm (W) * 14mm (height)
• Operating voltage :3.3 - 5 .5 V
• clock chip: high-precision clock chip DS3231
• Clock Accuracy :0-40 range, the accuracy 2ppm,  the error was about 1 minute
• Calendar alarm clock with two
• Programmable square-wave output
• Real time clock generator seconds, minutes, hours,  day, date, month and year timing and provide valid until the year 2100 leap year  compensation
• Chip temperature sensor comes with an accuracy of  ± 3 
• Memory chips: AT24C32 (storage capacity 32K)
• IIC bus interface, the maximum transmission speed  of 400KHz (working voltage of 5V)
• Wiring instructions (with Arduino uno r3 for  example):
  SCL → A5
  SDA → A4
  VCC → 5V
  GND → GND