Module Design of Multi-functional Intelligent Monitoring System for Solar Agricultural Greenhouse Based on GSM

I. Project Overview

1.1 Introduction

Today's greenhouse greenhouse industry is expanding, people's health requirements are getting higher and higher, and greenhouse greenhouses must have a suitable growth environment to improve the quality of agricultural products. This paper introduces the GSM-based solar agricultural greenhouse multi-functional intelligent monitoring system, which supplies power to the single-chip microcomputer through solar energy, sets the most suitable growth environment parameters required by different greenhouse plants, and the system detects the environmental value in real time and displays it on the liquid crystal module. If the setting parameters are different, the alarm device will be activated, and the information will be sent to the greenhouse manager through the GSM module, and the corresponding operation will be automatically taken. We believe that it will play an important role in future life, especially in greenhouses.

1.2 Project Background / Motivation

In the past two decades, China has attached great importance to the development of agriculture and made a lot of investment in agricultural facilities. Greenhouses are one of the most important projects. As a new type of agricultural crop planting technology, it has broken through the limitation of traditional crop cultivation due to many factors such as region, natural environment and climate, which is of great significance to agricultural production. The output has increased, but with the improvement of people's living standards, health has also been more concerned by people. The quality of agricultural products in greenhouses is also the focus of people's concern. However, how can green agricultural products in greenhouses grow best? At present, China's greenhouses rely on manual experience for management, or single-parameter control of single-chip, single-loop, people can not, through their own experience can accurately control the plant and other plants, the best suitable growth parameters. Greenhouse greenhouses are not highly automated and have low efficiency. In terms of the growing environment of crops, light, temperature and humidity are the most basic elements, and the intelligent monitoring system of greenhouses is the most important and most important link to achieve automation and high efficiency of production. As an intelligent monitoring system, it is necessary to collect, analyze, and process the data of the above factors, and carry out corresponding alarms and intelligent control, so that the crops in the greenhouse can grow in an optimal and suitable growth environment.

Second, the demand analysis

2.1 Functional requirements

The power required by the single-chip microcomputer is provided by solar energy, and the illuminance, temperature and humidity values ​​required for various plant growth can be set, and the system collects the environmental value in real time and displays it on the liquid crystal. If it exceeds the standard or is insufficient, the system will automatically alarm and automatically take the switch light, switch door, irrigation, roller blind and other operations. The system will send an alarm message to the greenhouse manager through the GSM module. The system can be used for large-area greenhouse cultivation, and can also be used for small-area cultivation of special plants. The system architecture is shown in Figure 2.1:

Figure 2.1 System Architecture

2.2 Performance requirements

Powered by solar energy, humidity measurement range: 20% ~ 90% RH, temperature measurement range: 0 ~ +50 ° C, signal transmission distance can reach more than 20 meters, the collected data information is displayed on the liquid crystal. The MCU controls the GSM module and sends the parameter information to the manager.

Third, the program design

3.1 System function realization principle

As shown in the following figure: The system is mainly composed of the following major modules: solar power supply module, sensor module (illuminance sensor, temperature and humidity sensor), GSM module, intelligent control module (switch door, switch light, irrigation, roller blind), Keyboard module, liquid crystal display module. The system hardware block diagram is shown in Figure 3.1:

Figure 3.1 System hardware block diagram

3.1.1 Solar Power Supply Module

Solar energy is a clean and renewable new energy source, which is more and more popular among people. It has a wide range of functions in people's lives and work. One of them is to convert solar energy into electrical energy, and solar cells use solar energy.

The solar power supply module uses 5 W polycrystalline silicon solar cells produced by Shenzhen Wanjiahao Solar Energy Co., Ltd., with a maximum voltage of 18V, and the photoelectric conversion efficiency of polycrystalline silicon solar cells is about 12%. In terms of production cost, it is cheaper than monocrystalline silicon solar cells, the material is simple to manufacture, saves power consumption, and the total production cost is low, so it has been greatly developed.

3.1.2 Sensor Module

Illuminance sensor: Illuminance is one of the important parameters of crop growth. In the facility agriculture, the detection of illuminance has been paid more and more attention by scientists. At present, most of the sensitive components used in the illumination detection circuit for environmental control of agricultural greenhouses in facilities are silicon photovoltaic cells. In fact, photodiodes have many advantages over silicon photocells, have high bandwidth, are inexpensive, and in particular have a good linear relationship between photocurrent and illuminance, so they are in optically coupled isolators, optical data transmission devices and test techniques. Widely used in applications. Therefore, the system is designed according to the photosensitive characteristics of the photodiode, and a simple and practical illumination detection circuit is designed.

Temperature and Humidity Sensor: Temperature and humidity are also very important for the growth of crops. This system uses DHT11 digital temperature and humidity sensor, which is a temperature and humidity composite sensor with calibrated digital signal output. It uses dedicated digital module acquisition technology and temperature and humidity sensing technology to ensure high reliability and excellent long-term stability. The sensor consists of a resistive wet sensor and an NTC temperature sensor connected to a high performance 8-bit microcontroller. Therefore, the product has the advantages of excellent quality, ultra-fast response, strong anti-interference ability and high cost performance. Each DHT11 sensor is calibrated in an extremely accurate humidity calibration chamber. The calibration coefficients are stored in the OTP memory as a program, and these calibration coefficients are called internally during the processing of the detection signal. The single-wire serial interface makes system integration easy and fast. Ultra-small size, extremely low power consumption, and signal transmission distances of up to 20 meters make it the best choice for even the most demanding applications.

3.1.3 GSM module