DS3231 Real Time Clock Module for Raspberry Pi (Without Battery)
The DS3231 Real-Time Clock (RTC) Module keeps accurate time for your Raspberry Pi and also works with Arduino. It tracks seconds, minutes, hours, day, date, month, and year, accurate up to the year 2100. The module adjusts to work with 3.3V or 5V, so it’s safe to use with Raspberry Pi. It has two alarms, a 1Hz and 32.768kHz output, and uses a fast I2C connection for easy setup. This low-power module also has a battery backup option (battery not included) to keep time when the main power is off.