I try using ds3231 RTC with R2. i2c enabled by “modprobe i2c”. Installed i2c-tools.
i2cdetect not detect any devices at 0x68 on 0,1,2 or 3 buses.
Wich bus used via GPIO header (GPIO 2,3) ? Bus 1 ? at R2 GPIO pinout 2 and 3 pins labeled I2C1_SDA.