Adafruit PCF8523 Real Time Clock Assembled Breakout Board
PCF8523 RTC breakout with battery backup for timekeeping when main power is removed. Communicates over I2C; operates at 3.3V or 5V supply and logic. Suitable for datalogging, alarms, and clock applications.
Pinout
- VCC
Power pin for the PCF8523 breakout. Adafruit Learn says to power it at the microcontroller logic level.
Type · PowerVoltage · 3-5VDC input, same as logic level - GND
Common ground for power and logic.
Type · GroundVoltage · 0V - SCL
I2C clock line.
Type · I2CVoltage · logic level follows VCC - SDA
I2C data line.
Type · I2CVoltage · logic level follows VCC - STEMMA QT
STEMMA QT connector on the STEMMA QT version for I2C/power chaining.
Type · UnknownVoltage · carries VCC, GND, SCL, and SDA - SQW
Square-wave output pin when enabled.
Type · Signal
| Pin | Type | Function | Voltage |
|---|---|---|---|
| VCC | Power | Power pin for the PCF8523 breakout. Adafruit Learn says to power it at the microcontroller logic level. | 3-5VDC input, same as logic level |
| GND | Ground | Common ground for power and logic. | 0V |
| SCL | I2C | I2C clock line. | logic level follows VCC |
| SDA | I2C | I2C data line. | logic level follows VCC |
| STEMMA QT | Unknown | STEMMA QT connector on the STEMMA QT version for I2C/power chaining. | carries VCC, GND, SCL, and SDA |
| SQW | Signal | Square-wave output pin when enabled. |
Pin details
6 connections- VCC
Power pin for the PCF8523 breakout. Adafruit Learn says to power it at the microcontroller logic level.
PowerVoltage · 3-5VDC input, same as logic level - GND
Common ground for power and logic.
GroundVoltage · 0V - SCL
I2C clock line.
I2CVoltage · logic level follows VCC - SDA
I2C data line.
I2CVoltage · logic level follows VCC - STEMMA QT
STEMMA QT connector on the STEMMA QT version for I2C/power chaining.
UnknownVoltage · carries VCC, GND, SCL, and SDA - SQW
Square-wave output pin when enabled.
Signal
RTC & timing
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