基于单片机的多功能称重系统

摘要

在微电子迅速发展的今天，在市场上用的传统的称重工具已经不能满足人们的要求，为了改变传统称重工具在使用上存在的问题，在本设计中将智能化、自动化、人性化用在了电子称重的控制系统中。本设计主要由单片机来控制，测量物体重量部分由称重传感器及A/D转换器组成，加上显示单元，此电子秤具备了功能多、性能价格比高、功耗低、系统设计简单、使用方便直观、速度快、测量准确、自动化程度高等特点。

本系统以AT89S51单片机为主控芯片，外围附以称重电路、显示电路、报警电路、键盘电路等构成只能称重系统电路板，从而实现自动称重系统的各种控制功能。此设计满足现代人们对科技的要求。

关键词：称重传感器、单片机、A/D转换器、LCD显示

Abstract

With the application of micro-electronics technology, tradition ponderation instrument used in market has been not satisfaction with hunman requirements already. In order to make up for the traditional apparatus shortcoming, we imp rove the apparatus's control system with intelligence and automation. This syste m is mainly controlled by microcontroller, the section of height measurement a ccomplish by supersonic sensor, the section of weight measurement accomplish by weight sensor and A/D transformer, this apparatus have many characteristic such as having more function, consume less energy, small and move easily, l ow price, measure precisely, the speed is quick, automatic work without people and so on.

The system is mainly controlled by the microcontroller AT89S52, the peri phery is consist of the circuit of clock and calendar, the circuit of measure hei ght and weight, the circuit of display and print, all of these comprise the circu it board of the intelligent apparatus of height and weight. It can achieve all fu nction of the apparatus.

KEYWORDS:SP20C-G501，AT89S52，ponderation –sensor，A / D

converter，LCDDisplay

目录

摘要...............................................................I Abstract...........................................................II

1绪论 (1)

1.1多功能称重系统的分类 (1)

1.2多功能称重系统的组成结构 (2)

1.3多功能称重系统的工作原理 (3)

1.4多功能称重系统的设计要求 (3)

2 总体方案设计 (4)

2.1具体方案选择 (4)

2.1.1传感器 (4)

2.1.2 A/D转换器 (5)

2.1.3显示器的选择 (6)

2.1.4键盘的选择 (7)

2.1.5单片机的选择 (8)

2.2 总体方案框架图 (9)

2.3小结 (9)

3 硬件电路设计 (9)

3.1采集电路的设计与实现 (10)

3.1.1传感器电路 (10)

3.1.2 放大电路 (11)

3.1.3 A/D转换电路 (12)

3.1.4 采集电路 (14)

3.2 显示电路 (15)

3.2.1 LCD1602介绍 (15)

3.2.2 LCD1602引脚功能 (16)

3.2.3 LCD1602与89C51的接口 (17)

3.3键盘模块 (17)

3.3.1矩阵键盘 (17)

3.3.2矩阵键盘中的键功能 (18)

3.3.3 键盘与89C51的接口 (18)

3.4 蜂鸣器模块 (19)

3.5 电源电路 (19)

3.6 MAX232通讯接口 (21)

3.6.1 串行通信的原理 (21)

3.6.2 MAX232简介 (22)

3.6.3 MAX232引脚图及功能 (23)

3.7本章小结 (23)

4 软件系统设计 (24)

4.1 编程语言及开发工具 (24)

4.2 LED显示程序模块 (24)

4.3 键盘模块 (24)

4.4 本章小结 (24)

5 仿真与实验调试 (24)

5.1proteus简介 (24)

5.2原理图 (25)

5.3仿真图 (26)

5.4本章小结 (26)

6总论 (27)

参考文献 (28)

致谢 (29)

附录A 程序清单 (30)