Introduction - If you have any usage issues, please Google them yourself
Using digital tube and AT24C02 implementation:
1, the digital tube displays from 0 to 99. After overflow, it displays from 0 cycles, with a time interval of one second.
2, display a number of time to turn off the power suddenly, AT24C02 will save the current number.
3, after reboot, the number will continue to display.