PCF8523 Real Time Clock for Raspberry Pi - Adafruit PiRTC
NXP's PCF8523 is a CMOS Real-Time Clock (RTC) and calendar optimized for low power consumption.
Some quick specs
- This is a great battery-backed real time clock (RTC) that allows your Raspberry Pi project to keep track of time if the power is lost. Perfect for data-logging, clock-building, time-stamping, timers and alarms, etc. Equipped with PCF8523 RTC, it works great with the Raspberry Pi and has native kernel support
- Works perfectly with any Raspberry Pi (or similar single board linux computer) including the Pi 1, Pi 2, Pi 3, Pi Zero, A+, B+ etc
- Fully assembled & tested PCB plugs directly into your Pi's GPIO pins - No soldering required!
- The PCF8523 is simple and inexpensive but not a high precision device. It may lose or gain a second or two per day
- Provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal
- Resolution: seconds to years
- Clock operating voltage: 1.0 V to 5.5 V
- Low backup current: typical 150 nA at VDD = 3.0 V and Tamb = 25 °C
- Needs a CR1220 coin cell battery for backup
- Datasheet
Direct connect board pinout
The six pin header connects directly onto pin 1 to 6 of the Paspberry Pi GPIO.
I²C Addressing
The PFC8523 has a default I²C address of 0x68 and cannot be changed!