微控制器如何使智能，更持久和可靠的接口

　　從根本上說，微控制器可以被描述為與日益復雜的外設緊密耦合的邏輯處理單元。通過將這個數字域耦合到現實世界，外設的功能和性能是微控制器功能中的一個定義參數。

　　最近，焦點可能轉向了MCU核心，但應用程序仍然很大程度上定義了所需的外圍設備集。MCUs繼續降低處理成本，更加多樣化和專用外設的出現，增強通用I/O（GPIO）的專用接口。

　　在最簡單的形式中，專用接口可能只是比較器，而不是ADC，但越來越多的外圍設備將激發（電壓或電流源）和測量（如ADC或DAC或電流感應輸入）結合起來。GPIOs是否應該由特定應用程序接口取代現在是經常的事大小的潛在市場和節約成本，可能會導致大量。一個這樣的應用空間是觸摸傳感器接口。

　　低成本觸摸接口的需求正在增長，因為增加交互性的能力不僅在一系列設備中提供更大的控制，而且也越來越受到人們的期望。

　　Touch technology

　　Historically， the most prevalent form of touch sensing has been resistive-based， where the sensing surface may overlay a screen or printed panel. The benefits of this approach are its simplicity and low cost; requiring few resources， it also has a relatively low-processing overhead， but may also be implemented using dedicated function blocks.

　　Typically， a resistive-screen interface operates by detecting small resistive changes across a planar surface formed by two conductive materials separated by an insulator. When pressure is applied to one surface， the resistance measured reduces. However， the key to this technology is in detecting where on the surface the pressure is applied in X and Y coordinates， which is ultimately dictated by the resolution. The smallest detectable location of an analog-resistive interface would typically be defined by the size of the surface， the absolute excursions of the resistance measurable， and the resolution of the ADC used to measure the resistance， and translate into a digital value.