用按键加减操作一个数字，数字变化后写入24c02，当关机重新再开机，调用上次最后使用的数值这种方式用于存储用户的自用数据和上次使用状态-Key subtraction operation with a number written after the digital change 24c02, re-boot when off, call the last number used in this way is used to store the value of the user s own d