软件触发改为用ADC看门狗中断的方式来寻找触发的位置，
边沿触发包含上升沿和下降沿触发，
修改水平位置左边为最近的AD值，
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Change software trigger to the way of ADC watchdog interrupt to find the
trigger position ,
Edge trigger contains the rising and falling,
Modify the horizontal position left for the recent AD values,