mpr121资料，很有用的英文资料。

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Freescale Semiconductor Application Note AN3891 Rev 1 032010 MPR121 Baseline System INTRODUCTION Touch acquisition takes a few different parts of the system in order to detect touch The baseline filter and touch detection are tightly coupled The purpose of the baseline filter is to filter out touches resulting in a system that is similar to a long term average but also takes into account that one specific signature A touch must have different properties than noise and environmental change wi......