I installed the RTC DS3231 without EEPROM module, together with the TFT shield mega shield v2.2, but it is not recognized by Ferduino, I have already used the I2C and RTC test codes, and none of them recognize the RTC module. I've tried replacing the Arduino via USB and external 9V and 12V sources, but it's still the same.
When I try to set the date by Ferduino, the date always returns to Sunday 0, 2000, even after saving the current date.
I also tested the DS3231 battery and it is normal voltage, I have already tested all the pins and soldering done and everything is normal.
I used pins 18 and 19 for connection as explained in this link: https://www.ferduino.com/forum/viewtopic.php?f=24&t=488
Note: I do not want to use pins 20 and 21 because I intend to use the PCF8575.
I'm lost, I do not know what else to do.