实现了一种应用于地下水行业的测控终端控制器的触摸屏及模拟量采集方案.阐述了德州仪器Sitara AM335 x微处理器的触摸屏控制器与模数转换子系统的结构和工作流程.采用软件方式同步转换步骤,遵从平台依赖驱动结构实现了四线制电阻触摸屏驱动程序,有效解决了触摸动作误判和触点跳动的问题;遵从流驱动结构实现了模拟量采集驱动程序,能够采集来自于水位计、流量计、压力计的标准4~20 mA电流信号.该方案结构紧凑,稳定性、可靠性强,适合基于AM335 x和 WinCE7.0嵌入式平台的控制器设计.%A touch screen and analog signal acquisition scheme for the measurement and control terminal controller used in underground water industry was implemented.The structure and working process of the touch screen controller and analog-digital converter subsystem of TI Sitara AM335X microprocessor was introduced.By both adopting software-ena bled mode to start each conversion step,a four-wire resistive touch screen driver according to the platform dependent driver structure and an analog acquisition driver according to the flow driven structure were implemented.The former can solve the problem of the touch action misjudgment and the contact bounce effectively and the latter has the ability to collect standard 4-20 mA current signal from water level meter,flow meter and pressure gauge.With the advantages of compact structure,high sta bility and high reliability,the scheme is very suita ble for the controller design based on AM335X and WinCE7.0 platform.
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