基于单片机的体重秤设计（电子称的设计）.doc

XXXX大学
毕业设计说明书
基于SN8P19系列单片机Auto-Run功能体重秤的设计
The Design of Weighing Scale Based on SN8P19 Series MCU Auto-Run Features
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20**年12月5日
摘要
现代社会随着人们生活水平的提高,人们对自己的身体健康越来越关注,而体重又是衡量身体健康与否的一个重要标准,因此用一台体重计定期测量自己的体重是很必要的。传统的体重秤是仪表形式的,不仅测量的误差比较大,而且读数很不方便,体积上会占用更多的空间。因此一款便携,易操作,测量精度高的体重秤就很能满足人们的需求。
本文以松翰SN8P1937单片机为核心,基于Auto-Run功能,当待测重量达到体重秤的开机重量时便开始称重,不像以前的体重秤要用脚踩脚踏开关才能开始称重。该单片机内部集成了16位的AD转换功能,可编程增益放大器,液晶驱动等丰富的片内资源。该系统只有在称重的时候在正常模式工作,此时会打开硬件资源,其他时间都工作在绿色模式,绿色模式芯片的电流只有几个微安,因此,该款体重秤非常省电,有很好的实用性和环保性。
该设计分为硬件设计和软件设计两大部分。硬件设计部分分为:LCD显示部分,压力信号采集与转变, EEPROM,低电压检测模块和部分按键。由于压力传感器的输出信号是非线性的,所以如果利用线性的处理方法有很大误差,使测量结果不准。因此采用分段线性的方法完成AD转换部分和放大电路部分的设计。软件部分先完成各个模块的底层驱动,然后完成应用层的设计,最终使系统达到预期的结果。
关键词:体重秤,SN8P1937,Auto-Run功能,压力传感器
Abstract
Modern society, as people's living standards improved, people e increasingly concerned about their health, as weight is an important factor whether healthy or not .It is important for people to use a scales to measure their traditional form of instrument scales are not only relatively large measurement errors, but also not easy reading,and volume of the scales will take up more a portable, easy operating, high precision scales, clearly meet the needs of the people.
In this paper, Sonix SN8P1937 MCU core, based on Auto-Run feature, it works when weight tested reaches the minimum of the weighing scales,unlike the previous of weighing scales use foot pedal to begin counting. The MCU integrates a 16-bit AD conversion, programmable gain amplifiers, LCD driver rich on-chip resources and so on. The system only weighing when in normal mode, open the hardware resources, the other time working in the green mode, green mode only cost a few microamps of current,so this kind of weighing scales is very power savings and have a good practical and environmental protection.
The design is divided into two parts, hardware design and software design. The part of hardware design is divided into: LCD dis