I have Arduino Nano and DS3231 RTC module, connected as requested, A4 to SDA, and A5 to SCL, 5V supply and GND.
I have tested every possible RTC library, but it does not work.
I2C scanner finds the EEPROM on 0x57 address, but not the RTC clock on 0x68.
Maybe Nano does not support this chip, but DS1307 only?
Please help anybody.
Thank you in advance.
Maybe Nano does not support this chip, but DS1307 only?
No, you can use a DS3231 with a Nano.
I2C scanner finds the EEPROM on 0x57 address, but not the RTC clock on 0x68.
Until the scanner can find 0x68 you can get no further. The fact that the scanner finds the EEPROM indicates that you have connected the SDA/SCL of the module correctly to the Nano. It's likely you have some kind of hardware problem on the module or a defective/counterfeit DS3231.
Find a schematic for your module.
Determine if there is continuity between the SDA/SCL pins on the chip and the pins connecting the module to the Arduino. Determine if the Power and Gnd pins on the chip are indeed connected to power and ground.
I use the library ds3231.zip that I found with a google search. It works fine, so you can try that one.