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 , with or with a

• 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 .

Technical Details

Revision History:

• As of March 25, 2022, this board now may come with a PCB version that has HVSON or SOIC-8 chip package depending on what chip is available in the market. Both are identical functionality!
• 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!

• Mounting holes are 2.2mm (0.086in) diameter, 25mm (0.98in) apart
• This board/chip uses I2C 7-bit address 0x68

Product Dimensions: 25.5mm x 21.7mm x 4.8mm / 1.0" x 0.9" x 0.2"

Product Weight: 1.2g / 0.0oz

Learn

• - Keep time at all times with a real time clock
• - I2C addresses from 0x00 to 0x7F (inclusive)
• - Tick tock, got a clock?
• - Easy keeb access to your TOTP keys.