代码功能/代码适用于V1.1版本

在屏幕上显示电池电压值
值得注意，精度不高，只能大致测量电池电压，电池使用二极管做防倒灌，因此需要在代码中修改补偿变量的值
可以通过对测量的值和万用表测量到万用表的差值就行比较后补偿
您可以通过电压值是否为 0 判断电池是否接入  电压值是否大于4.4V来判断是否接入了USB充电




Code Function/Code Applicable to V1.1 Version

Display the battery voltage value on the screen
It is worth noting that the accuracy is not high and can only roughly measure the battery voltage. 
The battery uses diodes to prevent backflow, so it is necessary to modify the value of the compensation variable in the code
Compensation can be made by comparing the difference between the measured value and the multimeter measured by the multimeter
You can determine whether the battery is connected to USB charging by whether the voltage value is 0 or not, and whether the voltage value is greater than 4.4V


