薄膜按键寿命测试装置设计

薄膜按键寿命测试装置设计(论文12500字)
摘要
薄膜按键是一块带触点的PET薄片按键开关，以其结构严谨外型美观，防潮湿，寿命长，价格低廉等优点常用于电子仪器和数控机床。薄膜按键使用寿命大约是在100万次以上，但因不同材料、使用环境、用户操作等因素寿命往往不到额定寿命，同类产品之间寿命差别也巨大。故本论文想要开发一种精确的薄膜按键寿命测试装置，代替人工进行快速有效的测试。
本装置选用宏晶公司STC15F408AD单片机作为整个系统的核心处理控制器，采用TB6560芯片驱动微型步进电机，利用步进电机正反转带动滑块上下按压薄膜按键，实现了模拟人手自动按压薄膜按键。同时单片机能够采集按键导通电压信号并对其进行处理，计算出导通电阻，通过测量薄膜按键导通电阻大小判定薄膜按键是否损坏，并用单片机内部EEPROM对按压次数和错误次数进行保存记录，显示在液晶屏上，从而直接显示出使用寿命。整个装置主要由机械装置和单片机，步进电机驱动电路及按键导通电阻测量相关外围电路组成
经过测试本薄膜按键测试系统能够实现步进电机驱动自动按键，检测速度大大提升，计数准确，导通电阻测量精度高，显示更新速度快，装置简单，成本低，应用前景广阔。
关键词：薄膜按键；单片机；寿命测试；步进电机
 
Abstract
Thin film key is a piece of PET chip key switch with contact. It is often used in electronic instruments and CNC machine tools because of its rigorous structure, beautiful appearance, anti-moisture, long life, low price and other advantages.The service life of the membrane key is about more than 1 million times, but due to different materials, service environment, user operation and other factors life is often less than the rated life, the life difference between similar products is also huge.Therefore, this paper wants to develop an accurate thin-film key life test device, which can replace manual test quickly and effectively.
This device select STC15F408AD Hong Jing company single chip microcomputer as the core controller of the whole system, driven by TB6560 chip micro step motor, using the stepper motor and reversing drives the sliding block press membrane keyboards, implements the mimics the automatic film buttons to push. And single chip microcomputer to collect keys conduction voltage signal and processing, calculate the conduction resistance, by measuring the film key on resistance size determine thin film is damaged, block and single chip microcomputer internal EEPROM to keep record, press the number and the number of errors is displayed in the LCD screen, thereby directly show the service life. The whole device is mainly composed of mechanical device and single chip microcomputer, stepper motor driving circuit and peripheral circuit related to the measurement of key on-resistance.
After testing, this film key testing system can realize the stepper motor driving automatic keys, the detection speed is greatly improved, the count is accurate, the on resistance measurement accuracy is high, the display update speed is fast, the device is simple, the cost is low,the application prospect is broad.
Key words: Thin film key;MCU;Life test; Stepper motor
 

目录
引言    1
第一章绪论    2
1.1研究目的及意义    2
1.2国内外现状    3
1.3论文主要内容    4
第二章系统相关器件    5
2.1 STC15F408AD单片机    5
2.2 微型步进电机    5
2.3工业串口屏    6
第三章按键寿命测试系统硬件设计    9
3.1系统结构设计    9
3.2系统组成    10
3.3按键导通电阻测量电路    11
3.3.1 测量原理    11
3.3.2恒流源电路    11
3.3.3电压信号处理电路    12
3.4步进电机驱动电路    14
3.5电源电路    16
第四章按键寿命测试系统软件设计    17
4.1 编译语言与编译环境    17
4.2 程序流程设计    17
4.3 人机交互界面    19
4.4 实验结果    20
结论    21
参考文献    22
谢辞    23