Innovative embedded teaching system for the Internet of Things

introduction

With the development of information technology, embedded system teaching still needs further exploration and improvement. In recent years, the rapid development of Internet of Things technology has provided a wider space for the application and development of embedded systems, and at the same time, it has also injected fresh blood into the teaching and practice content of embedded systems. However, while Internet of Things technology brings new opportunities to embedded systems, it also brings new challenges.

1 Internet of Things and Embedded Systems Course System

The concept of Internet of things (IOT) was proposed in 1999. According to the definition of the International Telecommunication Union (ITU) in 2005, the Internet of Things mainly solves the interconnection between things (Thing to Thing, T2T), people to things (Human to Thing, H2T), and people to people (Human to Human, H2H). This highly cross-cutting emerging frontier field has attracted much attention internationally. IBM of the United States proposed the concept of "Smart Earth" based on the Internet of Things; the Chinese Academy of Sciences started the research on sensor networks as early as the birth of the concept of the Internet of Things. In 2009, Wuxi Internet of Things Industry Research Institute was established, and the concept of "Perceiving China" was proposed during the inspection by President Xi Jinping.

Although there is no exact definition of the Internet of Things from a technical perspective, it is generally accepted that it integrates four key technologies: sensor technology, embedded system technology, modern network and wireless communication technology, and distributed information processing technology. It can be seen that embedded systems play a vital role in Internet of Things technology. Moreover, embedded systems and the Internet of Things have a complementary relationship: embedded system technology provides the necessary technical support for the development of the Internet of Things, promotes the engineering application of the Internet of Things, and enhances the industrial scale of the Internet of Things; while the development of the Internet of Things provides new application fields for the development of embedded system technology and provides a wider space for the application of embedded systems, which will inevitably help embedded system technology achieve a new leap forward.

As an emerging curriculum system, the embedded system course has attracted more and more attention from scholars. However, under the background of the rapid development of Internet of Things technology, the curriculum system of embedded systems should be adjusted to adapt to the development of the times. As shown in Figure 1, the curriculum system not only includes several basic courses such as sensors and single-chip microcomputers, but also includes the practical development of embedded systems, that is, the development and application of embedded systems for the Internet of Things.

Figure 1 Embedded Systems Course System for the Internet of Things

2 Theoretical teaching

The teaching content of embedded system theory mainly focuses on the application and cutting-edge development of ARM embedded microprocessors, embedded operating systems and embedded systems; the teaching purpose is to familiarize yourself with design methods and master embedded system development technology. Theoretical teaching is generally no less than 12 hours and no more than half of the total hours. The author generally controls it to about 16 hours, and the teaching content mainly includes:

a Overview of embedded systems;

b ARM core embedded microprocessor;

c Embedded real-time operating system and its transplantation;

d Embedded system cross development environment;

e Application of Internet of Things and embedded systems;

3 Embedded system experiments for the Internet of Things;

3.1 Hierarchical Experimental Design

Theoretical teaching provides the necessary knowledge foundation for the experimental practice link, while the experimental and practical links not only consolidate the theoretical foundation, but also further improve the hands-on ability and develop creative potential. The author selected the MagicARM2210S embedded experimental development platform of Zhou Ligong Company, which includes not only various mainstream serial interfaces and GPIO ports, but also Ethernet interfaces, GPS (Global Positioning System) module interfaces, CAN bus interfaces, etc. In view of these interfaces and the application background of the Internet of Things, the author designed three levels of experiments to meet the experimental and practical needs of different stages, as listed in Table 1. The experimental levels are from shallow to deep, and different experimental levels correspond to different experimental projects, and the organizational forms are also different. The main purpose of basic experiments is to familiarize yourself with the methods. The comprehensive experiments and innovative experiments are mostly based on the application of the Internet of Things, aiming to improve capabilities. The three levels of experiments are step-by-step and gradually improved, laying a good foundation for further practical development and graduation design.

Table 1 Hierarchical design of embedded experiments for the Internet of Things

3.2 IoT project practice

The importance of exercising and improving hands-on skills through project practice is unquestionable. In 2009, our school launched the "Application of Internet of Things in Forest Environment Monitoring and Protection" project. The author was responsible for the design of the embedded gateway of the middle layer of the Internet of Things. The main functional modules are shown in Figure 2. The GPS module interface mainly collects the longitude and latitude information of the terminal, while the wireless data transceiver module mainly collects environmental information such as temperature, soil moisture, and sunshine sent by each terminal sensor. These terminal information is packaged into UDP data packets through the ARM processor and transmitted to the base station server through the Ethernet network interface.

Figure 2 IoT gateway hardware block diagram

Through the second class, the author organized students with spare time to form interest groups, divided the IoT gateway into several sub-topics, and handed them over to each interest group to practice development in the form of simulated projects. For example, the sub-topic of "GPS data acquisition and processing" first needs to transplant the μC/OS operating system, then transplant the LwIP network protocol stack, and finally read the data from the GPS module interface in the form of multi-tasking and package it into UDP data packets and send it to the network. Among them, the members of the interest group need to divide the work reasonably and learn to cooperate in practice. After nearly a year of joint efforts by the author and the interest group, the embedded IoT gateway successfully transmitted the terminal sensor data deployed in Zijin Mountain to the base station network server. The environmental monitoring information of an IoT terminal is shown in Figure 3.

Figure 3 IoT terminal data

Through the practice model of the Internet of Things project, the learning content has been expanded and put into practice, which has further increased the interest in learning and cultivated the spirit of cooperation. It has also played a "point-to-surface" effect and effectively expanded the knowledge and hands-on ability.

In addition, in the graduation project phase, the author designs 3 to 4 embedded system design projects for the Internet of Things every year. After two years of practice, it has been proved that graduates who choose this type of project have a wider range of knowledge and a wider range of employment opportunities.

4 Conclusion

In the teaching and experimental practice of the ARM embedded system course, based on the rapid development of the Internet of Things, the theoretical teaching content is streamlined, and the knowledge is broadened, focusing on the design content closely related to actual engineering projects, especially the Internet of Things. The experiments are designed in a hierarchical manner, and the content keeps up with the development of the times. In the practical link, students are directly involved in cutting-edge topics and projects.