A Real Time Clock module (RTC) is an RTC is an RTC. Right? Wrong!
Whilst these two very common, Arduino-compatible RTCs appear very similar, and are connected via the I2C (pronounced Eye Squared See, or Eye Eye See) communications bus they perform quite differently, yet cost about the same.
The video shows how to use the modules and where to buy them but also highlights why the DS3231 should be the device of choice for all serious Arduino (and other microcontroller) developers - not least is the much improved, temperature-compensated accuracy and the on-board temperature sensor! Let's face it, the last thing you want to have to do is to connect the module back to your PC or laptop because the time has drifted by a couple of minutes. Especially when that Arduino project is buried inside that bee-hive at the bottom of the garden.
The next step in a future video will be to develop a code library to set the date and time using just two buttons (so using just two valuable pins on the Arduino) and which compensates for leap years, daylight saving time (UK-based but can be altered via the code for your part of the world). No more trips with your laptop precariously balance on the top of that bee-hive. (Spoiler: the code is written, it just needs turning into a library).
Have a peek at the video and do leave (constructive!) comments on how you think it might be improved in a future version, give it a thumbs up, share and if you have not already please subscribe to this Instructables channel - as well as my YouTube Channel (that way you don't miss any new videos, published weekly). Enjoy!