Hi everyone,

I recently found a helpful article that compares two popular real-time clock (RTC) modules — the DS1302 and DS1307. The guide explains their main differences, wiring methods, and how to use them in microcontroller projects like Arduino.
? Read it here: A Practical Guide to DS1302 and DS1307 RTC Module

Here’s a short overview:

• DS1302 uses a 3-wire serial interface (RST, I/O, SCLK). It’s low-power and has 31 bytes of RAM for small data storage.

• DS1307 uses an I²C interface (SDA, SCL) and includes 56 bytes of non-volatile RAM. It’s easier to connect when you already have other I²C devices on the same bus.

• Both modules can run on a backup battery and keep time accurately for months or years.

• The DS1307 often includes a square-wave output for timing applications, and some breakout boards even have pads for a DS18B20 temperature sensor.

The guide also shows example Arduino code using the RTClib library to display the date and time on an OLED screen and explains how to correct for clock drift caused by temperature changes.

I’m curious to hear from others here:

• Which RTC do you prefer — DS1302 or DS1307 — and why?

• Have you noticed any time drift in long-term use?

• Do you think modules like the DS3231 are now a better choice?

Would love to hear your thoughts or see your circuit setups using these RTCs.