OCTOPUS Real-time Clock is a clock module which can achieve counting for year month day hour by using the DS1307 clock chip.This chip has lots of merits low power supply with 56 bytes of non-volatile RAM clock calendar full BCD code real-time clock chip the address and data via a two-wire bidirectional serial bus transmission providing seconds minutes hours and other information automatically adjusting the number of days in each month. And more surprisingly the chip also equip with the function of leap year compensation. Chip has a built-in power-sense circuit brownout detection and battery switching function - Available for counting the seconds hours minutes days of month months days of week - With the function of leap year compensation. - Year recording to the limit of 2100. - 56 bytes of non-volatile RAM - Two-wire serial interface (IIC communication) - Programmable square-wave output - Automatic power-off detection and switching circuit - In battery backup mode power consumption is less than 500nA - Industrial operating temperature: -40 to 80 - Power supply needs: 5V and 3.3V - Interface type: Digital - Pin Definition: 1-GND 2-VCC 3-SCK 4-SDA 5-RST