论文总字数：41740字

摘 要

从在人民生活水平日益提高的今日，自动售货机已是随处可见，从自动售货机诞生到今日，过程中其本身已有了长足的进步。最初时只可投硬币, 到后来支持扫描纸币, 到再后来支持刷卡支付,随着中国通信基建的大力发展，4g通信和移动支付大大改变了中国人民的生活，与此同时自动售货机在我国人民生活中也越来越不可或缺。而如今鲜有人携带现金出门，因此投币售货机逐渐消失，通过成熟的4g网络实现自动售货机的移动支付已成为必然的趋势。

本课题基于在通信方面有众多优势的ModBus协议，和4g网络通信技术进行stm32软硬件设计。工业自动化通信协议中Modbus因为免费，兼容性强，开发成本低，操作灵活可以实现不同公司不同产品之间的数据通信而被广为使用。而4g则是现在主流的移动通信网络，传输速率快，成本低是其主要优点。

本文将重点介绍Modbus通信协议和4g通信技术。本课题基于4G和ModBus通信协议设计制作了自动售货机的控制系统。该系统硬件部分使用STM32系列微控制器和4g模块进行开发，能模拟自动售货机的选择商品，发出付款请求，付款完成购买的过程。

关键词： Modbus通信协议 4g通信技术 4g模块 STM32 自动售货机

Abstract

Nowadays, with the improvement of people's living standard, vending machine is everywhere. From the birth of vending machine to today, it has made great progress.From coin only at the beginning, to scanning paper money later, to credit card payment later, with the vigorous development of China's communication infrastructure, 4G communication and mobile payment have greatly changed the lives of the Chinese people, and at the same time, vending machines are increasingly indispensable in the lives of the Chinese people. Nowadays, few people go out with cash, so vending machines disappear gradually. It is an inevitable trend to realize the mobile payment of vending machines through the mature 4G network.

This paper is based on Modbus protocol, which has many advantages in communication, and 4G network communication technology to design STM32 software and hardware. In the industrial automation communication protocol, Modbus is widely used because it is free, with strong compatibility, low development cost, and flexible operation, which can realize data communication between different products of different companies. 4G is now the mainstream mobile communication network, its main advantages are fast transmission rate and low cost.

This article will focus on Modbus communication protocol and 4g communication technology.Based on 4G and Modbus communication protocol, the control system of vending machine is designed and manufactured. The hardware part of the system is developed by STM32 series micro controller and 4G module. It can simulate the whole process of vending machine to select goods, send out payment request and complete purchase.

Key words: Modbus communication protocol; 4G communication technology; 4G module; STM32；vending machine

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1 课题背景 1

1.2 现状 1

1.3 本课题所做工作 3

1.4 章节安排 3

第二章 自动售货机控制系统的主要技术 5

2.1 通信协议 5

2.1.1 通信协议介绍 5

2.1.2 RTU传输模式和ASCII传输模式的优劣分析 5

2.1.3通信过程中波特率的选择 6

2.2 6

2.2.1 的介绍 6

2.3 通信协议的介绍 6

2.4 RS485通信协议和ModBus通信协议的区别与联系 8

第三章 总体设计以及硬件设计 9

3.1 总体设计 9

3.2主机 10

3.2.1主机整体 10

3.2.2 4G模块 11

3.3 从机 11

3.4 STM32F103C8T6最小系统开发板 12

3.5 ML302 CAT1核心板模块 13

第四章 程序设计 14

4.1主机的main函数 14

4.1.1流程图 16

4.2ModBus协议RTU模式传输函数 16

4.3 用于发送数据的ML302程序模块 21

4.3.1 物联网卡激活相关部分 21

4.3.2 发送数据部分 23

4.4 RS485通信程序模块 25

第五章 实验结果 27

5.1 4G部分—OneNET云平台的调试结果 27

5.2 从机LED部分实验调试结果 28

5.3串口调试实验结果 29

5.3.1主机串口调试实验结果 29

5.3.2从机串口调试实验结果 31

第六章 论文总结及展望 32

6.1 论文总结 32

6.2 课题不足 32

6.3 课题展望 33

参考文献 34

附录 36

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