智能充电器实例功能：通过定时器定时从AD上读取数据，根据不同的电压选择不同的控制充电方案，使用PWM控制输出脉宽来控制电流-Intelligent charger instance function: Timer timer to read data from the AD, depending on the charging voltage to select a different control scheme, using the PWM control output pulse width to control the current