3PCS DS3231 Real Time Clock Module RTC Sensor High Precision AT24C32 IIC Timer Alarm Clock for Arduino Raspberry Pi

I got this module because I was getting constant errors about my time not being synchronized. I tried everything I could from setting NTP to installing various distros such as Ubuntu, Ubuntu Server, RaspiOS and Dietpi but nothing worked until I got this module.So, look no further and grab this if you need to have your time in sync.As a side note, if you are using a Raspberry Pi, please connect the module like this:VCC --> 5VSDA --> Pin3SCL --> Pin5GND --> Pin6Also, you need to use a rechargeable battery such as the LIR2032.I hope this helps.

These RTC work great on my Pico Microcontroller project. Easy to set up.

These modules do work ok. They do not come with batteries but use the common CR2036 battery. They work fine however they don't keep the time totally accurate. Seem to run a little fast. I have used other models that kept better time. However for the price really not too bad.

The description of this item is deceiving. It states you will receive the SN chip, describes all of the capabilities and workings of an SN, and then in little text down at the bottom says they ship the SN, N and M at random - text I did not see until opening all 3 packages. Inconveniently I received all Ms, the cheapest and least reliable of the 3, it looses the most time and does not use a crystal oscillator. Additionally the M requires regular batteries, not rechargeable like the others, so I had to cancel an order for the LIR2032s. Theres no way to guarantee which model you get, so order at your own risk if you specifically need the SN. My project will be fine with an M, but I am not excited about it. Otherwise, the product is at least an RTC module, just not one that meets the exact specifications on 90% of this listing. Please be aware, that despite the picture this does not come with batteries. Which batteries you need will depend on which model you randomly receive.

Although photos clearly show batteries, package did not come with batteries.

Work great and I like that these have a replaceable coin cell battery. My first one years ago had a permanently fixed battery.

This is a bargain priced piece of electronics. I got the project box from Amazon:https://www.amazon.com/dp/B07RTYYHK7?ref=ppx_yo2ov_dt_b_product_details&th=1It is extremally accurate so there is no need for adjustments.One reviewer wrote the Vcc pin is not active, totally wrong. When Vcc applied the LED on the clock comes on.Getting the firmware was a bit time consuming since I hadn't used the IDE and had to update it, there were some conflicts with libraries (LCD libraries).I recommend it.

These RTC units worked fine. However, the picture of the item showed 3 clock modules WITH batteries, while mine came without batteries. It's not a huge deal, but sending along the batteries did sway me to buy from this vendor. Whatever happened to truthful product descriptions?