Arduino library for the DS1302 Real Time Clock chip
C++ Arduino

DS1302 RTC library for Arduino

This project is a library for the Arduino platform. It provides a simple interface to the Maxim DS1302 timekeeping chip. It allows Arduino projects to keep accurate time easily.


Of the features on the DS1302, this library provides support for:

  • Setting and retrieving the time, using the burst modes.
  • Setting and clearing the Write Protect (WP) flag.
  • Setting and clearing the Clock Halt (CH) flag.
  • Setting and accessing the 31 bytes of static RAM. Single-byte and multi-byte (burst) modes are supported.
  • Low-level register access.

Trickle charging support is the only major feature of the DS1302 not directly supported by this library. However, trickle charging can be enabled using the low-level register access functions if desired.

Examples and documentation

The header file is well-commented, and the examples directory contains example sketches for immediate use.


Place the DS1302 directory in the libraries subdirectory of your Arduino sketch directory. On OS X, for example, your sketch directory might be:


In that case, you should put the DS1302 directory at: