DS3231 Real Time Clock Module High Precision AT24C32 IIC RTC Sensor for Arduino Nano Mega2560 Leonardo Raspberry Pi (Pack of 5)

No issues with these - 2nd order. I immediately test all low price consumer components, having had issues in the past.These work fine on either 3.3 or 5 V, and they keep time - these are I2C based and work with Arduino, Raspi and Beagle Bones with zero issues.

If you get this module, no matter from who you do, please read the documentation online. There is a resistor just next to the SCL, that requires to be removed ONLY, if you are NOT using a rechargeable battery. If you use the common CR2032 you must remove it.

After a week of use as a persistent RTC for a Pico (RP2040), it has maintained the time and date without any issues. I paired it with some of the Amazon Basics CR2032 batteries, and have had no issues there. I haven't had a chance to play with the alarms yet to wake the micro controller on a schedule, but I suspect it will work well too.The only thing I wish was different with these was the battery case is about twice as high as necessary to hold the battery, but it appears to be connected via 2 through-hole pins that are soldered on, so I think I can desolder the battery holder and replace it with a more flush version.

This is the basic 3231 clock module, it's easy to hook up and sketches can be easily found for it. It also has 2 interrupts which can be accessed through the SQW pin. You can set it to interrupt once a minute, a number of seconds in the future from now(), and I believe once a day. This can be used for many things. Use the Alarm sketch to test this. Uses CR2032 battery.

All five modules worked fine in my project but I only required the 1Hz square wave output. Be aware that of the five modules received, two (2) had DS3231M chips and three (3) had DS3231SN chips. The “M” variety do not allow you to modify the square wave ( SQW) output. If this isn’t an issue for your project, have fun!

I needed a clock chip for an Arduino project to keep the time. I'm not great at programming but there are lots of videos and guides out there to help out. The product works as expected. I would buy it again.

Works as expected. Easy to find documentation online. Need to remove a chip resistor to use a backup battery.

tested chips. Loses 2-4 minutes/day. TERRIBLE.