DS3231 saying no I2C device found

Projects Programming
1

I have a simple setup to show time and date in serial monitor using DS3231 & Arduino UNO. but the constantly getting messages like NO I2C DEVICE FOUND OR SOME RANDOM SIMBOLS.

CURRENT SETUP

  • Arduino UNO
  • DS3231
  • ARDUINO POWERED BY USB

CONNECTION SETUP

  • 5V TO 5V
  • GND TO GND
  • SDA TO A4
  • SCL TO A5

WHAT ALL TRIED

  • Tried changing DS3231 with new module.

  • Tried with different jumper cables.

  • Tried program given by ChatGPT, Youtube, Gemini

  • LED in the module is turning on in both OLD & new RTC module.

  • Tried uploading I2C scanner program it is showing.
    No I2C devices found :cross_mark:
    Scanning...

  • One time i got a program from google it worked once i was getting all the data then i removed RTC and connect it back one more time after that it is not communicating.

2

Upper case is considered shouting, and no it does not help.

Have you tried a library written by experts?
As I do not see the code it is hard to say where things has gone wrong.

3

What was the result? Did it return the I2C address of the DS3231 module?

Have you tried any of the examples in the IDE from File -> Examples -> DS3231?

There are a number of DS3231 breakout boards around. Which one are you using? (Could you post a link or a photo?) Do you know whether it has pull-up resistors on the I2C (SDA/SCL) pins?

8

Hi @ABHISHEK_P ,

feel free to read and follow this website

https://wolles-elektronikkiste.de/en/ds3231-real-time-clock

to receive comprehensive information and assistance how to handle a DS3231.

9

Show us a picture of the supposed DS3231. Many are actually ZS-042 which has some issues. Get a Chronodot which is a proper DS3231.

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10
  • Scanner program didn't return the I2c address.
  • I used the inbuilt sketch also but unable to find the device
  • when i tries the scanner program it is showing
    "No I2C devices found:
    Scanning..."
  • there are pull up resistors in my module
12

Verify connections and scanner with another I2C module.

13

photo_2025-07-21_23-00-13
photo_2025-07-21_23-00-13721×1280 103 KB

Arduino
Arduino721×1280 141 KB

this is the connection details

14

Looks like this --

It may not appreciate a 5V environment --

image
image600×386 62.8 KB

15

  • If you have a different I2C module is it detected with I2C scanner ?

  • Have you tried different wires ?

  • Check all the PCB component soldering.

16

Connect the Ds3231's Vcc pin to UNO's 3.3V pin and try it, if it's a 3V only module it may already be ruined by connecting 5V.

17

Those pictures are not useful. Draw by hand then post a picture of your drawing.

18

In your picture, I can see 5VDC on the UNO going to the 3.3VDC on the RTC board. That is wrong. Move the wire to the left four positions to where it is labelled 3.3V

19

Adafruit figures it is, or at least theirs is, ok with 5V.

20

I don't have a solution for you, but I think you can studiously ignore posts 16, 17, and most particularly 18. The red LED on the DS 3231 module alone suggests you have wired it like everybody else does, and the photos confirm that. But read post #15 again!
Also, ZS-042 is merely the breakout board and there has never been a suggestion that there is anything other than a kosher ds3231 on it, but you might scrutinise it for slack soldering. I understand there are solder bridges to determine the address, so that might be the place to look.

21

photo_2025-07-21_23-00-13
photo_2025-07-21_23-00-13721×1280 103 KB

Arduino
Arduino721×1280 141 KB

this is the connection

22

For the second and LAST time. Hand-draw a wiring diagram, then take a photo of it and post it as a reply to this post.

23

Actually the ZS-042 has a lot of issues. At least some if not all have a recharge circuit for the battery but it is mostly shipped with a NON rechargeable battery. The LED is not a good idea for an RTC that needs to minimize the battery draw.
And while I don't understand the details, prople who's opinion I respect tell me the I2C pull down resistors need to be removed as they are the wrong value and I think the EEPROM pulldowns need to be removed if the EEPROM isn't being used.

24

I dont see an obvious issue with the wiring so I would try connecting to 3.3V instead like suggested. If that doesnt work, try switching SCL and SDA, could be mislabelled on module

1 Like
25

Ah, the word clock.

1 Like