+ 24C32 32K I2C EEPROM Memory
+ DS1307 based RTC with LIR2032 battery
+ Backup by AT24C32 32Kbit
+ DS1307,AT24C32 can work separated
+ Leads to the DS1307 clock pin, to provide the clock signal for the microcontroller
1. DS (not used)
2. SCL (I2C bus clock)
3. SDA (I2C bus data)
4. VCC (+5V)
+ These units work well with Arduinos, it is as simple as connecting 4 wires, +V, ground, and the two I2C bus wires which gives access to both the real time clock and EEPROM.
+ The real time clock will not run unless initialised (It keeps it's data in RAM which can be cleared by removing the battery which also de initialises it).