DS1302(without battery) is introduced trickle charge the clock chip, containing a real-time clock / calendar and 31 bytes of static RAM, via a simple serial interface
to communicate with the microcontroller. Real-time clock / calendar circuit provides seconds, minutes, hours, days, weeks, months, years of
information, the number of days per month and leap year automatically adjust the number of days. Clock can be done by the AM / PM or 12 
decided to use 24 hour format. Between the DS1302 and the microcontroller can simply use the synchronous serial communication mode, used 
only three port lines: (1) RST Reset (2) I / O data lines (3) SCLK serial clock. Clock / RAM read / write data to a byte or up to 31 bytes of character 
set way communication. DS1302 low-power work to maintain the data and clock information when power is less than 1mW
Real time clock with the year 2100 to calculate the seconds, minutes, hours, days, weeks, months, years, the ability, as well as the ability to leap 
year adjustment
1.31 8 temporary data storage RAM
2.Serial I / O port pin makes the least number of ways
3.Wide range of operating voltage 2.0 5.5V
4.Current 2.0V, less than 300nA
5.Read / write clock or RAM data transmission when there are two single-byte transmit and multi-byte character sets transfer mode
6.8-pin DIP package or optional 8-pin SOIC package assembly according to the surface
7.simple 3-wire interface
8.Vcc = 5V and TTL-compatible
9.Optional industrial temperature range -40 to +85
10.Dual power tube for the main power and backup power supply

Parameters:
1.PCB a single panel, size: 42mm * 24mm * 12mm(max)
Net weight:10g 
Package weight:20g 
Color:green (as the picture shows)
2 with 4 holes, about 3.1mm in diameter
3 genuine spare battery for the celestial sphere CR2032, Voltage 3V, current is 260mAh, non-rechargeable batteries. 
4 Crystal 32.768KHz, matching capacitance 6pF, size 2 * 6mm
5.DS1302 made large 8-pin DIP chip, chip, IC Block below for easy replacement and plug the chip
6 module operating voltage compatible 3.3V/5V, 5V and 3.3V microcontrollers can be connected with
7 Operating temperature: 0℃ --- 70 ℃

NOTE:
Wiring (to provide the program, for example, can take any IO port, the port defined in the program can be modified):
VCC → +5 V/3.3V
GND → GND
CLK → P02
DAT → P01
RST → P00
1.VCC and GND must not be reversed, or it will burn the chip
2.51 MCU P0 port requires a pull-up, if your single-chip pull-up resistor is not connected, you can port the data cable to the other

WE PROMISE YOU CAN GET THE ITEMS YOU PAID OR REFUND.