High Precision Electronic Scale Design Based on MCU
KUANG Xinghong
1, a
, YAO Zheyi
1, b
, Wang Zhiyu
1, c
,Wang Shiming
1, d
Department of Automation, Shanghai Ocean University, Shanghai, China
a
xhkuang@shou.edu.cn,
b
zyyao@shou.edu.cn,
c
zyyao@shou.edu.cn,
d
,smwang@shou.edu.cn
Keywords: Electronic Scales; Weighing Sensor;LM331;MCU
Abstract. This paper introduces a design of the High Precision Electronic Scale Design Based on
MCU, Hardware circuit reaches data processing by the control unit which based on MCU, and The
MCU gathers data by weighting sensor, then the LM331 makes V/F transform, and the transformed
data then transferred to MCU for display processing. At last, the LCD would show it out steadily
without twinkling. The paper mainly puts forward the scheme and software design idea, hardware
design.
Introduction
Since ancient times, the weighing technology is closely related with people's lives. It is widely
used in various fields of industry, agriculture, transportation, and scientific research, internal and
external trade. So it has also become an indispensable part of people's lives. With the development of
science and technology and the continuous improvement of human productivity, measurement
accuracy requirements are also increasing. Therefore, the electronic scales which takes the vast
majority of weighing tasks, has also got more and more attention. The accuracy of weighing
technology requirements are increasingly high, electronic products, technology level, directly
influences the level of modernization and professions to improve the economic benefits of the
society.
In recent years, the electronic weighing technology achieved rapid development, electronic
weighing in the metrology area also plays more and more important position, and its applications are
constantly expanding. Especially, because of its commercial electronic with high accuracy, sensitive
reaction, simple structure, etc, have been widely applied in industry and commerce trade, light food,
medicine and health, etc. At present, mechanical scales are gradually replaced by electronic, this has
led to the further study of electronic. Electronic scales are one of the electronic weighing
instruments.
This paper describes the design of the High Precision Electronic Scale Design Based on MCU.
The hardware and the software are described in detail in the paper.
The general principle of weighing electronic scale
When the object placed in the weighing scale body, the weight data is transferred to the weighing
sensor through the scale body. The sensor generates force electric effect. And then, weight signal
will be converted into electrical signals such as current or voltage in certain functions, (Usually, they
are assumed to the high proportional relationship).The signal is amplified by the amplifying circuit
and filtered by the filter circuit, and converted by an analog-to-digital (A/D) converter. Digital
signal is then sent to the MCU. MCU constantly scans the keyboard and each function switch, and
analysis the information from the keyboard. The result will be send to the memory and display the
result on the screen. Generally, amplification, filter, A/D conversion and signal processing steps are
completed at the weighing electronic scale.
General design of the High Precision Electronic Scale
According to the requirements function of the design, the system consists of 6 parts: Data
acquisition module, signal processing circuit module, power supply module, MCU module, keyboard
module and the memory module. The structure of system circuit is shown in Fig. 1.
Applied Mechanics and Materials Online: 2013-09-27
ISSN: 1662-7482, Vols. 427-429, pp 616-619
doi:10.4028/www.scientific.net/AMM.427-429.616
© 2013 Trans Tech Publications, Switzerland
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans
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