脉冲测量可以返回某个电平状态持续的时间例如下列程序中当12号管脚状态为高时返回该状态持续的时间状态超时返回0利用脉冲测量可以测量速度，频率等思考如何测量PWM的输出频率Serial115200SerialprintlnHIGH12此块相比与脉冲测量多了一个超时状态，状态持续超过设置时间返回 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