The DS3231 is a highly accurate I2C real-time clock (RTC) with a built-in temperature-compensated crystal oscillator (TCXO). Accuracy is ±2ppm, and it maintains time even with power off using a CR2032 backup battery.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | 32KHZ | 32.768kHz square wave output | I/O |
| 2 | VCC | Supply voltage | PWR |
| 3 | INT/SQW | Interrupt or square wave output | I/O |
| 4 | RST | Reset output, open drain | I/O |
| 5 | SCL | I2C clock | BUS |
| 6 | SDA | I2C data | BUS |
| 7 | GND | Ground | GND |
| 8 | VBAT | Backup battery input | PWR |