摘要从20世纪60年代开始，电子称重技术作为一门新兴技术快速发展起来，它是集传感器技术、测量与控制技术、计算机技术、微电子技术、物料输送技术和管理技术等为一体的综合技术，具有广泛的应用领域，中药的自动称重和包装就是典型的应用之一。68317

本课题主要是针对小企业所使用的中药自动称重系统的硬件电路设计。根据小型中药自动称重的要求，对其核心的称重控制器进行设计，具体包括传感器的选型、信号的放大、A/D转换、串行通信等内容，称重误差可控制在1%以内。

硬件电路采用量程范围为0-5kg的电阻应变式传感器获得采集物体重量信息，然后通过称重专用芯片HX711对采集到的模拟量进行放大及完成AD转换，最后由单片机STC89C52进行数据处理及控制。考虑到对物体单价的输入及最基本的去皮等功能的需求，电路中通过4×4的小键盘向单片机输入相关指令。经过处理后的信息通过LCD1602进行显示。

本设计不仅完成了硬件电路的设计，还编写了相关软件，完成了实物的焊接与调试，证明了系统的可行性。

毕业论文关键字：电子秤 压力传感器 STC89C52单片机 HX711

毕业设计说明书（论文）外文摘要

Title  Miniaturized automatic weighting system of Chinese                                                                                                                                                                        Medicine

Abstract

Electronic weighing technology appeared in the 1960s,and it has been developing rapidly.It includes sensor technology, measurement and control technology, microelectronic technology, computer technology, material handling technology and management technology.It has extensive applications.Automatic weighing and packaging systerm of Chinese medicine is one of the typical applications.

This subject is mainly to complete the design of hardware circuit  of miniaturized weighing system of Chinese medicine .According to the requirement of this weighting systerm,I design the core of the weighting controller,including the selection of sensors, signal amplification, A/D conversion, serial communication etc.Requirements for weighing error is controlled within 1%.

The resistance strain sensor ranging from 0kg to 5kg measured object weight information.Then Chip HX711 will deal with the information by amplification and AD conversion.At last Single chip microcomputer STC89C52 processes the data and control the systerm.Considering the price of the input and the most basic peeled functions,I add a small keyboard to input commands to the microcontroller.The processed information is displayed through the LCD1602.

This design not only completed the hardware circuit design, but also completed the relevant software and the welding and debugging of the real, proving the feasibility of the system.

Key words Electronic scale  Load sensor  STC89S52  HX711

目  次

1 绪论 1

1.1课题研究背景及意义 1

1.2 国内外研究现状 1

1.3 发展方向展望 2

1.4 电子称重系统关键技术 3

2 系统硬件方案设计