DS3231 AT24C32 Real-Time Clock

12/20/18

Last modified on 12/20/18

Categories: Electronics Tags: Modules Arduino

DS3231 is an accurate I2C real-time clock. Arduinos cannot keep good time on their own, so an RTC module or Internet clock is needed for reliable timekeeping. These modules include a coin cell holder for a CR2032; the coin cell allows the unit to keep time when the Arduino is reset or otherwise loses power.

32K (32KHz square wave output)
SQW (Square wave or interrupt output)
SCL - A5
SDA - A4
VCC - 5V
GND - GND

Investigating this IC, the datasheet shows some interesting features:

This is a really cool chip. My module has a 32K AT24C32 memory chip as well as a few analog pads, A0, A1, and A2. According to manufacturuer, the 24C32 addresses can be shorted A0/A1/A2 modify default address is 0x57.

Many libraries available. NeiroNx’s RTCLib provides the usual as well as a getTemp method for the DS3231 RTC object, though this is not documented in the examples.

Resources:
https://thecavepearlproject.org/2014/05/21/using-a-cheap-3-ds3231-rtc-at24c32-eeprom-from-ebay/ https://publiclab.org/notes/cfastie/01-30-2018/real-time-and-temperature