DS3231，精度超高，STM32F103控制的模拟I2C总线，本人在项目里经常使用这个芯片，驱动也经过长时间验证，应该是刚健的(DS3231, ultra high precision, I2C bus simulation of STM32F103 control, I often use this chip in the project, driving after a long time of verification, should be vigorous)