RTC Plug

The RTC Plug is a small board containing a DS1340 real-time clock with battery backup, so that it continues to track the time when the power is switched off.

Note: this plug was initially called a “Clock Plug”. The text on the above boards hasn’t been adjusted yet.

An I2C bus running at 3.3V is used for I/O, with all the power and signal lines brought out to to both sides of the board to allow daisy-chaining with other I2C-conformant boards.

For additional details, see


There is nothing to configure. The RTC chip on this plug responds to I2C address 0x68.

Header Pinouts

Design Info

Dimensions: 21.1 x 31.8 mm
CadSoft EAGLE design files: see below.
This plug can be operated at 5V as well as 3.3V.

This board uses the conventions of a JeePlug and can be used with the ports on a JeeNode. It can also be used with other boards and MCU’s, if you hook it up properly and adapt the interface code for it.

How to Get It

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