How to use DS3231 RTC

[vintm]

TinkerOS_Android V13.13.0.74

Release Notes
4. Support DS3231 RTC module.

The  DS3231 module is connected to the port I2C_1, when I write in terminal :
"1|root@rk3288:/ # hwclock -r -f /dev/rtc1"
I see the time and date
"Tue Jan  4 23:54:11 2000  0.000000 seconds"

When I write in terminal :
"1|root@rk3288:/ # hwclock -w -f /dev/rtc1"
hwclock: failed: No such file or directory

How to useDS3231 RTC as hardware clock instead rtc0?