WaveShare RTC WatchDog HAT (B) DS3231SN 40PIN 2 in 1 accessory

Real-Time Clock and Watchdog HAT

The WaveShare RTC WatchDog HAT (B) combines a high-precision DS3231SN real-time clock with a hardware watchdog in a single compact module. It is designed for Raspberry Pi series boards and Jetson Nano projects that require accurate timekeeping and automatic system recovery. The board connects through the standard 40PIN GPIO header.

Compatibility and Power Check

Verify that your single-board computer exposes a standard 40PIN GPIO header with I2C lines available for the DS3231SN chip. The module requires a backup battery for the real-time clock to maintain time during power loss; the holder is onboard but the battery itself is not supplied. Ensure your software stack can drive the I2C monitoring circuit for the auto-reset watchdog function.

Build and Daily Use

The compact PCB fits directly onto the GPIO header without additional cables, leaving adjacent pins accessible for other HATs. Gold-plated header pins provide reliable contact through repeated insertions. The onboard battery holder accepts a standard coin cell, allowing the clock to run for extended periods without main power. No moving parts or active cooling are present, so the module operates silently in embedded environments.