My goal , I want to make time check device and put it in 3 place.
I want the devices are sync time in milisec level.
I design each device have RTC and use ESP read RTC every 1 sec. At The first time 3 RTC in 3 devices must set the same time.
Now I try to sync 3 RTC on i2c I set RTC use same address But it not work, RTC are set time but it's not same time.