構(gòu)建移動多傳感器系統(tǒng)由觸摸屏為主

　　移動設(shè)備似乎都有觸摸屏顯示器，也經(jīng)常有許多其他傳感器。理解底層技術(shù)可以幫助您評估這些設(shè)計中不可避免的權(quán)衡。

　　現(xiàn)代游戲、醫(yī)療和移動設(shè)備主要由集中顯示為主要用戶界面的觸摸顯示器所主導(dǎo)。然而，這些產(chǎn)品大多是可以從多種類型的傳感器中受益的系統(tǒng)，用于確定位置、運動和其他環(huán)境條件。使用模型和反應(yīng)決定的觸摸界面，可以使用的類型?？衫玫膫鞲衅黝愋?、開發(fā)和應(yīng)用支持、產(chǎn)品實現(xiàn)問題以及分級可用性將得到解決。

　　觸摸傳感器

　　有多個觸摸傳感器的接口和技術(shù)可。幾個有針對性的大面積應(yīng)用或需要線式電力執(zhí)行。移動空間是這些接口的新的“量”的地區(qū)。移動空間的指南包括17英寸以下的顯示器、電池操作、斷電模式、毫秒響應(yīng)時間和設(shè)備上的單個用戶。這些要求將主流觸摸技術(shù)縮小到三種類型：電阻式、投射式電容式和表面電容式。這三個技術(shù)概述如表1所示。

　　Resistive touch is one of the oldest and simplest technologies. The touch screen is based on a flexible conductive layer （generally coated with Indium-Tin-Oxide ［ITO］） that is spaced above another ITO conductive layer. When the top layer is flexed or depressed， it makes contact with the bottom layer and then creates a localized voltage change. The location of the voltage change is sensed， and that determines the position of the touch， as shown in Figure 1. This is a high accuracy technology， as the flex of the top layer can be from a large area object such as a gloved finger， or a very small area such as the end of a stylus. The technology also allows for weather and dust/foreign material resistance by allowing the edges of the top layer to be sealed. Digi-Key carries resistive touch control ICs from ten suppliers - Analog Devices， Inc.， Atmel， Integrated Device Technology （IDT）， Maxim， Microchip Technology， National Semiconductor， ROHM Semiconductor， Semtech， STMicroelectronics， and Texas Instruments （TI）。 The resistive touch ICs for the display systems， including those used by cell phones， are all supported by development systems featuring access to all stages of the data pipeline. Development systems such as the EVAL-AD7877EBZ-ND from Analog Devices， Inc. include software， cables， a touch sensor， control electronics， and a display. These systems allow for the application development and real-time test of the sensors. The high speed of resistive touch systems， in addition to the ability to have sealed displays， continued operation when moisture or fluid is on the screen， and a firm non-accidental touch， makes resistive touch the preferred technology for industrial control and medical electronics.