Adafruit
Adafruit PCF8523 Real Time Clock Assembled Breakout Board
Keep track of time even when your project loses power or gets reprogrammed. The PCF8523 Real Time Clock breakout is a battery-backed RTC that communicates ov...
Keep track of time even when your project loses power or gets reprogrammed. The PCF8523 Real Time Clock breakout is a battery-backed RTC that communicates over I2C and works with both 3.3 V and 5 V power and logic. Perfect for datalogging, clock building, time stamping, timers, and alarms.
Works with Arduino (using the Adafruit RTC library), CircuitPython, and Raspberry Pi or other single-board Linux computers. For higher precision (temperature-compensated), see the DS3231 Precision RTC. For DS1307 compatibility, see the DS1307 RTC Breakout.
Key Features
- PCF8523 RTC Chip – Battery-backed real-time clock with I2C interface
- 3.3 V and 5 V Compatible – Works with both power and logic levels
- CR1220 Battery Backup – Keeps time for 5+ years on a coin cell (battery not included)
- Breadboard Friendly – PCB and header included, plugs straight into a breadboard
- Two Mounting Holes – For permanent installation
Compatibility
- Arduino (Adafruit RTClib library)
- CircuitPython / Python
- Raspberry Pi and other Linux SBCs
- Any microcontroller with I2C support
Ideal For
- Datalogging with accurate timestamps
- Clock and alarm projects
- Scheduled task execution
- Time-stamped sensor readings
Package Contents
- 1× Adafruit PCF8523 Real Time Clock Breakout, assembled with header
Resources
- PCF8523 RTC Learn Guide – Code, libraries, schematics, and wiring diagrams
Jargon buster
Plain-language definitions for the technical terms used above.
- breakout
- A breakout is a small circuit board that makes a tiny or hard-to-solder component easier to connect to with standard pins. It matters because this OLED module can be wired into a microcontroller project without needing to solder directly to the display’s fine contacts.
- CircuitPython
- A beginner-friendly version of Python designed to run directly on microcontroller boards. If a product supports CircuitPython, you can often program it by copying code files onto the board rather than setting up a more complex toolchain.
- I2C
- I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.
- microcontroller
- A microcontroller is a small computer on a chip that runs your program and controls connected inputs and outputs. For this product, it is the part that reads buttons and sensors, drives the display and speaker, and communicates over Bluetooth.
- PCB
- A printed circuit board is a rigid board with copper tracks that connect electronic parts without loose wires. For this kit, the PCBs also form the airplane shape, so they are both the circuit base and part of the finished model.
- RTC
- A Real-Time Clock keeps track of time even when the main processor is asleep or powered down, usually with a small backup battery. It matters for data logging and tracking projects that need accurate timestamps.
Find this product in
Brands
Sensors & Input
Related Tutorials
Free guides on learn.littlebird.com.au
