【作者】 罗中华；

【导师】 方安安； 陈志龙；

【作者基本信息】 南昌大学 ， 电子与通信工程， 2008， 硕士

【摘要】 LED显示屏是利用发光二极管点阵模块或像素单元组成的平面式显示屏幕。由于它具有发光率高、使用寿命长、组态灵活、色彩丰富以及对室内外环境适应能力强等优点,在国外得到了广泛的应用。本设计使用增强型单片机+CPLD+大容量存储方案作为主控制模块,。由点阵显示控制板计算出显示图形的点阵码,通过控制data和pulse引脚,输入某行的数据,然后选通该行,利用简单的数字电路外围来驱动128*32的点阵LED显示屏,LED显示屏将得到该行的点阵显示。这样逐行扫描,得到整屏显示效果。为了解决普通的点阵显示板在显示屏略大时,容易出现干扰和延迟,显示会有明显的抖动。我们抛弃原电路中众多芯片,使用基于CPLD的点阵显示板,成功地对系统中的大量外围电路进行了简化和集约,提高了显示板的可靠性和稳定性,也有利于电路的测试和检修。通过改进方案后我们的显示板在实现原有功能的基础上大大提高了性能,成功的解决了抖动的问题。在数据传输方面,我们利用增强型单片机本身强大的功能,通过串口RS232与上位机通讯,根据串口接受的汉字内码查询位于固化在ROM中的汉字显示点阵库,从而形成显示点阵码;在LED显示控制板的RAM中建立一个与LED显示屏相对应的显示缓存区,将显示的汉字的点阵码存在该缓存区中,LED显示控制板不断将显示缓存区中的数据以串行移位方式移进点阵显示屏的显示锁存寄存器,并通过相应的行选开关的选择来实现显示屏动态行扫描。为了减少引脚且便于封装,LED显示点阵模块采用阵列形式排布,即在行列线的交点处接有显示LED。微机通过总线操作控制来完成对每一个LED点阵显示模块内每个L E D显示点的亮、暗控制操作,从而实现L E D显示屏汉字或图象的显示控制操作。可以很方便的实现与PC机和外围存储设备的数据传输,并能利用软件方便的进行显示内容的多样变化,在整个设计过程中从硬件到软件都作了优化,成功实现屏体显示的多样化,使各项指标都基本达到了预先的设计要求。更多还原

【Abstract】 LED display is use light-emitting diode dot matrix module or flat-display screen consisting of pixel modules.Because it has the advantages of a high rate of luminous,long service life,configuration flexibility,rich colors,a strong ability to adapt the environment indoor and outdoor and so on. So it has been widely used in foreign countries.The dot matric display control panel calculates the dot-matrix code of display graphics.By controlling the date and pulse pin,input the data of some line, and then strobethe line. And by using a simple digital circuit peripheral to drive 128*32 dot matrix LED display ,LED display will get the dot-matrix disply of the line. After line-by-line scanning it will obtabe the whone screen disple.In order to solve the cornmon dot-matrix disple interferenced,delayed and obvious jitter when the display screen is slightly latger,we discard many chips in the original circuit and use the dot matris display based on CPLD .It simplfies and integrates many peripheral circuits in system successfully,and improve the reliability and stability of the display board, and is useful for the circuit testing and maintenance . By improving scheme our display board in achieving the original function has greatly improved the performance ,and solve the peoblem of jitter successfully.In data transm ission we use enhanced SCMits own styong function ,through the serial port RS232 communicating with the suprior mochine .According to the chinese characters inner code accepted by the serial port inquire the Chinese characters display dot matrix storehouse solidified in the rom,and form display port inquire the chinese characters display dot matrix storehouse solidified in ROM,and form display dot mabix code.In the RAM of LED diaplay control panel establish a diaplay buffer area related with LED display, and then store the dot matrix code of display Chinese characters in this buffer area. LED diaplay control panel will move the data in diaplay buffer area to the diaplay lock regidter of dot matrix diaplay in the serial moving manner continually,and accomplsh diaplay dynamic line scanning by the choice of relative line selected switch.In order to reduce the number of pins and easy to package,LED dot-matrix diaplay LED.Computer through the bus operational control achieves esch LED diaplay brighe and dark control opersttion in esch LED dot matrix diaplay modules,thus achieve LEDdiaplay Chinese characters or graphics diaplaycontrol operation.It can easily achieve the data transmission witch PC and peripheral strage devices,and facilitate to change variously display contents with the use of software,In the whole design process,it has been optimized from hard ware to software,and achieves the variety of screen diaplay successfully.So all indicators have reschde pre-design requiremens basically.更多还原