排序方式: 共有87条查询结果,搜索用时 15 毫秒
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单片微型计算机键盘接口设计 总被引:1,自引:0,他引:1
介绍了单片机系统中矩阵式键盘的特点和工作原理,以及大规模集成电路8255A。给出了8255A和MCS-51单片机的接口电路,以及实际应用中的软件设计框图等。 相似文献
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串行接口LED数码管及键盘管理器件ZLG7289A的原理与应用 总被引:2,自引:0,他引:2
介绍了LED数码管及键盘管理器ZLG7289A的原理与应用。该芯片具有SPI串行接口,可同时驱动8位共阴式数码管(或64只独立LED),还可连接多达64键的键盘矩阵,单块芯片即可完成LED显示、键盘接口等全部功能。文章给出了ZLG7289A的特点、引脚功能、指令说明和经典电路.并以单片机AT89C51为例,给出了其接口电路及相应源程序。 相似文献
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介绍了一种键控式的采用单片机对高频函数发生电路进行程序控制的高频信号发生器的设计方案。此方案能产生方波、正弦波和三角波等信号;采用数字频率合成器,使输出信号频稳度和晶体振荡器的相当;并用键盘设置波形和频率,由LED显示。输出信号的频率分成1 MHz~16 MHz和8 kHz~999 kHz两挡。 相似文献
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Daniel Xu Andreas Tairych Iain A. Anderson 《Journal of Polymer Science.Polymer Physics》2016,54(4):465-472
Practice makes perfect to some extent. Research has shown that musicians who practice the piano for long periods of time can suffer a range of hand problems from loss of control to diminished speed. Now imagine a rubber keyboard that is springy, soft, and elastic. This is the new type of input device that dielectric elastomers (DE) can create. However their usage in large sensing systems is limited by a scalability challenge. Each DE sensor is married to a pair of connection cables and electronics, adding to the complexity of the background overheads. A new efficient multi‐frequency method is presented that is capable of detecting internal pressure changes from a difference in the DE's capacitance without the need for any additional wires or connections. This effectively segments the DE into smaller sections, achieving information from a single sensor equivalent to multiple sensors. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 465–472 相似文献
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A robust system for backlit keyboard inspection is revealed. The backlit keyboard not only has changeable diverse colors but also has the laser marking keys. The keys on the keyboard can be divided into regions of function keys, normal keys, and number keys. However, there might have some types of defects:incorrect illuminating area, non-uniform illumination of specified inspection region (IR), and incorrect luminance and intensity of individual key. Since the illumination features of backlit keyboard are too complex to inspect for human inspector in the production line, an auto-mated inspection system for the backlit keyboard is proposed in this paper. The system was designed into the operation module and inspection module. A set of image processing methods were developed for these defects inspection. Some experimental results demonstrate the robustness and effectiveness of the proposed system. 相似文献
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为了实时获取生产线上大量按键并发动作状态,提出一种基于FPGA的多按键状态识别系统设计。该系统设计采用VHDL语言描述,有效地解决远距离、分散、多键并发状态识别问题,并减小电路板面积和单片机的信号连接,易于对大量按键并发输入操作。给出了该系统设计方案的硬件电路设计和仿真结果。该设计已成功应用于某项目中。 相似文献
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键盘经常作为嵌入式开发和应用的外设。使用Windows CE作为嵌入式操作系统,IntelR○公司的PXA255作为主控芯片进行嵌入式平台的开发时,由于Windows CE上提供了对PS/2键盘输入的支持,而PXA255本身不带PS/2控制器,所以不能直接使用PS/2键盘作为输入外设;如果对键盘的物理层传输端口进行变通,而传输的内容仍符合PS/2协议,则可以利用Windows CE自带的键盘驱动程序,实现高效的键盘输入;PXA255上集成有同步串口控制器(SSPC),所以使用基于8051核的通用单片机模拟同步串口作为键盘的物理层传输端口,来实现PS/2键盘输入。 相似文献
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