Design of 3D environment monitoring system based on AVR microcontroller and wireless sensor network

1 Overview

1.1 Documentation

This design document is the plan for "3D environmental monitoring and evaluation system based on AVR32 and Labview", which is the basis for the project and also serves as the description of the project.

1.2 Project Background

This project hopes to use AVR microcontrollers as the basis and cooperate with the Zigbee protocol stack disclosed by Atmel to conduct comprehensive data collection on existing green spaces, abandoning the original outdated and irrational green coverage area standards, and instead using 3D coordinates to measure the specific values ​​of each environmental parameter in each small area, draw a 3D image, and use the three-dimensional environmental improvement status as an effective indicator for analyzing the use value of green spaces. The data obtained from the test will guide the establishment of the most appropriate and positive greening facilities based on the environmental characteristics of different areas.

This project will also be able to achieve unified data collection for various complex environmental data, such as real-time measurement of temperature and humidity, inhalable particulate matter, ozone content and other indicators, and ultimately establish a three-dimensional coordinate model to stereoscopically reflect various environmental indicators in the green space, and then combine it with the plant model to establish a three-dimensional greening efficiency model, so as to reasonably and effectively monitor the specific role of different plants in urban green spaces in improving human living conditions and optimize the efficiency of urban green space construction.

From the two pictures above, we can see that the oxygen content of the same green space may vary greatly due to different plants planted in different places. Therefore, it is unreasonable to blindly pursue the area of ​​green space. Only by looking at the benefits of green space from a three-dimensional perspective can we effectively evaluate green space.

1.3 Overall Project Plan

1. Familiar with the application environment and programming language of AVR and Zigbee wireless sensor network.

2. Further explore the subject, analyze and summarize the relevant data that needs to be collected and extrapolated to achieve the subject objectives.

3. Based on the clear purpose and general method, further plan the system structure and derive a detailed and feasible system block diagram in theory.

4. First, we will tackle the programming problem of Zigbee wireless sensor network, that is, design a wireless sensor network program that theoretically has the ability to collect data, and obtain reasonable sensor distribution points through calculation.

5. Cooperate with the development of Zigbee and then start the program development of AVR processor, which serves as the terminal for aggregating Zigbee data and improves the function of AVR processor.

6. Practical application: the data received through the Zigbee wireless sensor network is summarized and displayed by the AVR microprocessor, and the system modulation is carried out based on this.

7. Further improve the data processing function of the microprocessor so that it has high-level capabilities for data-based drawing and analysis.

1.4 Project Features

In the past, the environmental protection level of a city was often measured by such an indicator - "green coverage rate". As a result, we have seen the rapid rise of green parks and artificial lakes around us. However, is such a simple accumulation of "green" really environmentally friendly and healthy? The answer is obviously no. As we all know, the original intention of planting a large number of green plants is to absorb carbon dioxide in the air through the light and effect of green plants to purify the air quality. However, the question that follows is - do all green plants have the same environmental protection function? Obviously not. Therefore, instead of blindly building green spaces, it is better to reasonably and effectively match plant species according to the environmental conditions of different regions. Therefore, how to perceive and collect data on environmental parameters in different areas of the green environment is particularly important. This is the background of this project.

1.5 Project Innovations

The biggest innovation of this project is that it overturns people's long-standing outdated understanding of the efficiency of green space construction, that is, the "coverage rate only" theory, wrongly and blindly building green space, simply aiming for high coverage rate. Now, with this project, we hope to convert the original two-dimensional data distribution map into three-dimensional data, that is, to take into account the environmental characteristics of different regions, and comprehensively evaluate the greening effects of different greening types, which will also include the collection and evaluation of various data such as air quality and inhalable particulate matter. In short, the indicator of "green coverage rate" will be converted into "environmental improvement rate per unit area" to test various environmental indicators in three dimensions.

Another major innovation of this project is to use wireless network sensing technology to complete the collection and sampling of data within a certain range. Different from the traditional data collection through manual observation, this project aims to realize the environmental data monitoring of green space through a wireless sensor network based on Zigbee and AVR. By reasonably placing monitoring nodes in the area and coordinating relevant node interconnection programs, the environmental conditions are monitored and detailed and comprehensive monitoring data over a period of time is completely counted. This is the first time in this field that environmental protection exploration and innovation are carried out through such means.

2. Tools

2.1AVR32

The AVR32 UC3 Flash microcontroller has a built-in DSP instruction set and uses a three-stage pipelined Harvard architecture. The architecture is specifically designed to optimize the instruction fetch process from on-chip Flash memory. The microcontroller is the industry's first core to integrate single-cycle read/write SRAM with a direct CPU interface that skips the system bus for faster execution, cycle resolution, and lower power consumption.

The UC3 series of microcontrollers have up to 512KB flash memory and 64KB on-chip RAM, and can provide 80 Dhrystone MIPS (DMIPS) of processing performance with the industry's best performance/power ratio. For example, the new AVR32 UC3B device can provide 72 Dhrystone MIPS (DMIPS) of performance at a rate of 60MHz, including true single-cycle MAC and DSP algorithms, and at a voltage of 3.3V, the current is only 40 mA. The power consumption of the UC3B series MCU is only as low as 1mW/DMIPS, which is 3 times lower than other architectures with the same functions. When using a single 3.3V power supply, the standby current is only 30uA; when using dual power supplies (1.8V/3.3V), the standby current is less than 15uA.

Available peripherals include Ethernet MAC, full-speed USB device and On-the-Go (OTG), as well as a peripheral DMA controller, multi-layer high-speed bus architecture, 10-bit ADC, SPI, SSC, two-wire interface (I2C compatible), UART, general-purpose timers, pulse width modulator (PWM), and a complete set of supervisory functions.

2.2Labview

LabVIEW (Laboratory Virtual instrument Engineering Workbench) is a graphical programming language development environment. It is widely accepted by industry, academia and research laboratories as a standard data acquisition and instrument control software. LabVIEW integrates all functions for communicating with hardware and data acquisition cards that meet GPIB, VXI, RS-232 and RS-485 protocols. It also has built-in library functions that facilitate the application of software standards such as TCP/IP and ActiveX. This is a powerful and flexible software. It can be used to easily build your own virtual instrument, and its graphical interface makes the programming and use process lively and interesting.

A graphical programming language, also known as the "G" language. When programming with this language, you basically do not write program code, but instead write a flow chart or block diagram. It makes use of terms, icons, and concepts familiar to technicians, scientists, and engineers as much as possible. Therefore, LabVIEW is a tool for end users. It can enhance your ability to build your own scientific and engineering systems and provide a convenient way to implement instrument programming and data acquisition systems. Using it for principle research, design, testing, and implementation of instrument systems can greatly improve work efficiency.

3. System and software block diagram