The DS1302 trickle-charge timekeeping chip contains a real-time clock/calendar and 31 bytes of static RAM. It communicates with a microprocessor via a simple serial interface.
Only three wires are required to communicate with the clock/RAM: CE (chip enable), I/O (data line) and SCLK (serial clock). Data can be transfered to and from the clock/RAM 1 byte at a time, or in a burst of up to 31 bytes. The DS1302 is designed to operate on very low power, and retain the data and clock information on less than 1 µW.
A 32.768 kHz Crystal with a 6 pF load capacitance is needed (sold separately).
Features:
- Counts seconds, minutes, hours, date of the month, month, day of the week, and year
- Leap-Year Compensation Valid Up to 2100
- Supports 24 hour mode or 12 hour mode with AM/PM indicator
- 31 byte of static RAM
- Package Type: 8-pin DIP
Key Specifications:
- Power Requirements: 2 to 5 VDC; less than ~300 nA
- Communication: TTL-compatible 3-wire synchronous serial
- Operating Temperature: -32° to +185° F (-0° to + 70° C)
- Dimensions: 0.4 x .025 in (10 x 6.4 mm)
Downloads & Resources:
Dallas Semiconductor 1302 Datasheet (.pdf)
DS1302 Demo Code
Javelin Stamp Example Code (.zip)