长春大学基于PIC16F877A智能电子秤的设计目录第1章前言.............................................................11.1选题的背景和意义................................................11.2国内外电子秤发展及成果..........................................21.3研究现状........................................................31.3.1影响因素...................................................31.3.2产品质量...................................................31.3.3发展方向...................................................41.3.4电子秤的智能化.............................................41.4电子秤设计的任务及要求..........................................4第2章系统方案设计与论证...............................................62.1系统方案的设计思路..............................................62.2系统方案设计....................................................62.3系统方案比较与论证..............................................62.3.1单片机的选型...............................................62.3.2称重传感器选型............................................102.3.3放大部分选型..............................................142.3.4A/D转换器选型............................................142.3.5显示模块选型..............................................162.3.6键盘输入选型..............................................182.3.7语音芯片选型..............................................19第3章系统硬件设计....................................................203.1基于PIC16F877A的主控电路......................................203.1.1PIC16F877A简介...........................................203.1.2PIC16F877A引脚介绍.......................................203.1.3主控电路设计..............................................213.2称重部分.......................................................223.2.1GF-7桥型称重器简介.......................................223.2.2工作原理..................................................233.2.3硬件电路..................................................233.3测身高部分.....................................................243.3.1超声波测距原理............................................243.3.2测身高硬件电路设计........................................24i┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊长春大学基于PIC16F877A智能电子秤的设计3.4显示部分.......................................................263.5语音播报部分...................................................273.6键盘部分.......................................................283.7报警电路.......................................................283.8电源电路.......................................................293.9硬件低功耗设计.................................................293.9.1低功耗元器件选择..........................................293.9.2低功耗电路设计............................................30第4章软件设计........................................................314.1称重部分软件设计...............................................314.2测身高部分软件设计.............................................32第5章结论............................................................36致谢.................................................................37参考文献...............................................................38ii┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊第1页共4...
