Adafruit PCF8523 Real Time Clock Assembled Breakout Board
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.
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