The Adafruit PCF8523 Real-Time Clock Breakout keeps track of time even when your microcontroller loses power, with battery backup, 3.3V/5V compatibility and support for Arduino, CircuitPython and Raspberry Pi. CR1220 battery not included.
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!
Please 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. If you need a DS1307 for compatibility reasons, check out our DS1307 RTC breakout.
Features
Battery-backed real time clock (RTC) with PCF8523 chip
Maintains time during power loss or microcontroller reprogramming
Compatible with 3.3V or 5V power and logic
Works with Arduino, CircuitPython, Raspberry Pi and Linux single board computers
Ideal for datalogging, clocks, time stamping, timers and alarms
PCB and header included
Breadboard compatible or connect via wires
Two mounting holes for secure installation
Provides timekeeping for 5+ years with coin cell battery
Accuracy: may lose or gain up to 2 seconds per day
Coin cell battery (CR1220) sold separately
Specifications
Mounting holes are 2.2mm (0.086in) diameter, 25mm (0.98in) apart
This board/chip uses I2C 7-bit address 0x68
Dimensions: 25.5mm x 21.7mm x 4.8mm
Weight: 1.2g
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!
