This is a great battery-backed real time clock (RTC) that allows your microcontroller project to keep track of time even if it is reprogrammed, or if the power is lost. Perfect for datalogging, clock-building, time stamping, timers and alarms, etc. Equipped with PCF8523 RTC - it can run from 3.3V or 5V power & logic!

Works great with an Arduino using our RTC library, with CircuitPython or with a Raspberry Pi (or similar single board linux computer)

• PCB & header are included
• Plugs into any breadboard, or you can use wires
• Two mounting holes
• Will keep time for 5 years or more

Note: This product does not come with a CR1220 coin cell battery. We recommend you purchase a coin cell battery to use with this product.

The PCF8523 is simple and inexpensive but not a high precision device. It may lose or gain up to 2 seconds a day. For a high-precision, temperature compensated alternative, please check out the DS3231 precision RTC. 

Revision history:

• As of Aug 30, 2017 we have updated the design to have an RC filter on the power supply to reduce accidental resetting if power drops too fast!

Dimensions:

• Length: 25.8mm/1.02in
• Width: 21.8mm/0.86in
• Height: 5mm/0.2in
• Weight: 2.3g/0.09oz
• Mounting holes are 2.2mm(0.086in) diameter, 25mm(0.98in) apart
• This board/chip uses I2C 7-bit address 0x68