微控制器如何使智能，更持久和可靠的接口

　　微控制器如何使智能，更持久和可靠的接口

　　从根本上说，微控制器可以被描述为与日益复杂的外设紧密耦合的逻辑处理单元。通过将这个数字域耦合到现实世界，外设的功能和性能是微控制器功能中的一个定义参数。

　　最近，焦点可能转向了MCU核心，但应用程序仍然很大程度上定义了所需的外围设备集。MCUs继续降低处理成本，更加多样化和专用外设的出现，增强通用I/O（GPIO）的专用接口。

　　在最简单的形式中，专用接口可能只是比较器，而不是ADC，但越来越多的外围设备将激发（电压或电流源）和测量（如ADC或DAC或电流感应输入）结合起来。GPIOs是否应该由特定应用程序接口取代现在是经常的事大小的潜在市场和节约成本，可能会导致大量。一个这样的应用空间是触摸传感器接口。

　　低成本触摸接口的需求正在增长，因为增加交互性的能力不仅在一系列设备中提供更大的控制，而且也越来越受到人们的期望。

　　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.