design of a solar model for controlling brightness levels of a led system based on a light sensor

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATIONFACULTY FOR HIGH QUALITY TRAININGGRADUATION THESISMAJOR: ELECTRONICS AND COMMUNICATIONENGINEERING TECHNOLOGYDESIGN OF A SOLAR MODEL

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATIONFACULTY FOR HIGH QUALITY TRAINING

GRADUATION THESIS

MAJOR: ELECTRONICS AND COMMUNICATIONENGINEERING TECHNOLOGY

DESIGN OF A SOLAR MODEL FOR CONTROLLING BRIGHTNESS LEVELS OF A LED SYSTEM BASED ON A LIGHT SENSOR

ADVISOR: PhD NGUYEN THANH NHIA

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATIONFACULTY FOR HIGH QUALITY TRAINING

GRADUATION THESIS

MAJOR: ELECTRONICS AND COMMUNICATIONENGINEERING TECHNOLOGY

DESIGN OF A SOLAR MODEL FOR CONTROLLING BRIGHTNESS LEVELS OF A LED SYSTEM BASED ON A LIGHT SENSOR

ADVISOR: PhD NGUYEN THANH NHIA

Foremost, we would like to express our sincere thanks to the lectures in the Faculty of Hight Quality Training During the time of studying at school, teachers were dedicated to teaching and imparting out team knowledge, experience, and motivation in the learning process.

Moreover, we would like to express my gratitude for his continued support and encouragement: Nguyen Thanh Nghia We consider that: His guidance and advice are the best opportunity for us to complete this thesis.

Another, we would like to thank our friends who share knowledge and valuable experiences during the implementation of the thesis

Finally, we would like to thank our families who have put in the time, effort, and support our team during the implementation of this thesis.

Sincerely thank you!

Ho Chi Minh City, Dec 28, 2021

A GUARANTEE

We here with formally declare that this thesis is our research and implementation I have not copied from any published articles without quoting the source If there is any violation, I accept full responsibility.

Author

(Sign with full name)

Today, when technology is increasingly developed, people’s lives and needs are improved, research are more and more interested in technical and technological applications that bring benefits and do not cause harm to the enviroment When it comes to green energy, it is impossible not to mention that the abudanet energy that is avaible and does not cause harm to the earth’s enviroment is the source of solar energy Currently, builduings and commercial areas all the use solar energy as the main fuel source to convert electricity to light complexes, commercial areas, or buildings That’s why our team chose the topic : ”Design of a solar model for controlling brightness levels of a LED system based on a light sensor” to modoernize street light equipment by using solar energy and adjusting it The brightness is suitable for shining in when it is dark compared to the traditional street lights today The system uses the central microcontroller ESP8266, light sensor BH1750, solar panel, storage battery, and LED chip 2835, etc Because of improving the utility of streets light using solar energy, the thesis has designed a webserver using ESP8266 to convert WIFI so that can display information about the percentage of the battery reserve, the brightness level of the lights, and the operating mode that users can use it more conveniently and can monitor when place have WIFI.

The result after the poject is that the LED works stably and automatically like the LEDs solde on the market as the goal of the topic The system has the advantage of being able to support users to monitor thorugh the webserver, have longer lighting capacity thanks to the use of PWM technology However, the system also has the disadvantage that our team is working on a model, so some aesthetic problems are not high, but sill ensure wate resistance when the device is operating outdoors.

CHAPTER 2 LITERATURE REVIEW 4

2.1 SOLAR ENERGY EXPLOITATION AND PRODUCTS 4

2.1.2 Application of solar panel 4

2.2 ENERGY-OPTIMIZING SYSTEMS 5

2.2.1 LEDs replace other lamps in application 5

2.2.2 Pulse width modulation (PWM) 6

3.1 INTRODUCTION 10

3.2 HARDWARE CALCULATION AND DESIGN 10

3.2.1 Block diagram 10

3.2.2 Calculate and design circuit diagrams 11

a Central processing block (ESP8266) 11

b Design of PWM circuit 12

c Design of switch circuit 14

d Design of divider circuit 17

e Design of source circuit 18

f Principle of operation 22

g Principle of diagram 23

3.3 SOFTWARE DESIGN 23

3.3.1 Flowchart of main program 23

3.3.2 Flowchart of battery saver 25

3.3.3 Flowchart of operating mode 25

3.3.4 Flowchart of voltage check 26

3.3.5 Flowchart of update webserver data 27

CHAPTER 4 CONSTRUCTION OF THE SYSTEM 29

CHAPTER 5 RESULT AND DISCUSSION 35

5.1 RESULT OF MODEL EXECUTION 35

5.1.2 The system’s console 36

a Main screen interface 36

b Auto mode interface 37

c Manual mode interface 38

5.2 COMMENTS AND REVIEWS 40

5.3 INSTRUCTION DOCUMENT 40

5.4 ESTIMATING CONSTRUCTION COSTS 41

CHAPTER 6 CONCLUSION AND FUTURE WORK 43

6.1 CONCLUSION 43

6.2 FUTURE WORK 43

REFERENCE 44

APPENDIX 46

ABBREVIATIONS

SDIO Secure Digital Input Output

UART Universal asynchronous Receiver Transmitter

LIST OF TA

Table 2 1 Comparision of PWH Techniques 6

YTable 4 1 List of components used in the system 29

Table 4 2 List of components used for simulati 32

YTable 5 1 Experimental data of LED in auto mode 40

Table 5 2 Experimental data of LED in manual mode 40

Table 5 3 Cost for components, materials used in the model 4 Y

LIST OF F

Figure 2 1 The front of system model after completion 4

Figure 2 2 Module of the system 5

Figure 2 3 A LED chip 2835 7

Figure 2 4 Light intensity sensor BH1750 9

YFigure 3 1 Block diagram of system 10

Figure 3 2 Circuit of central processing 11

Figure 3 3 PWM circuit 13

Figure 3 4 Switch circuit 14

Figure 3 5 Schematic of divider circuit 17

Figure 3 6 Schematic of charging circuit 18

Figure 3 7 Schematic of power supply circuit 20

Figure 3 8 Schematic diagram of the whole system 23

Figure 3 9 Flowchart of main program 24

Figure 3 10 Flowchart of battery saver 25

Figure 3 11 Flowchart of operating mode 26

Figure 3 12 Flowchart of the voltage check 27

Figure 3 13 Flowchart of update webserver data 28

YFigure 4 1 Front of PCB circuit 30

Figure 4 2 Backside of PCB control circuit 31

Figure 4 3 Front of board circuit 31

Figure 4 4 Backside of board circuit 32

Figure 4 5 Model of the system 33

Figure 4 6 Webserver interface on IPad 33

Figure 4 7 Webserver interface on computer 34

YFigure 5 1 Module of LED 35

Figure 5 2 Inside of the LED module 36

Figure 5 3 Webserver interface after logging browser 36

Figure 5 4 Webserver interface with auto button ON 37

Figure 5 5 Auto mode with LED on 37

Figure 5 6 Auto mode with LED off 38

Figure 5 7 Webserver interface with manual button ON 38

Figure 5 8 Manual mode with LED off 39

Figure 5 9 Manual mode with LED on 39

CHAPTER 1: INTRODUCTION 1.1 OVERVIEW

The development of science and technology has significantly contributed to the change in our life Science and technology are drastically developing, which increases energy consumption leading to the depletion of energy resources Therefore, we need to find a solution to save energy while ensuring the efficiency of our equipment.

Nowadays, in addition to exploiting energy from heat and water to produce electricity, we are gradually familiar with phrases such as: “solar electricity” The fact that we exploit and use solar energy is one the “green solutions'' to find new energy sources without causing negative impacts on the environment However, so that we can waste these sources of energy In the scientific paper: “Solar energy for electricity and fuels” by Olle Ingana s, Villy Sundstro m, research on energy conversion and solar energy applications [1] Their research the benefits of using solar energy, and solar energy receiving materials In particularly, they further researched artificial photosynthesis, methods to produce direct solar fuels It can also be shown that the impact of finding new energy and saving it is an important issue In addition, the topic “Thiết kế chế tạo bộ điều khiển đèn chiếu sáng công cộng sử dụng năng lượng mặt trời” of Vu Tien Dat, Nguyen Minh Vuong, on manufacturing an optimal charge controller for batteries in the energy lamp system are based on a chip using ATmega128 connected to the Sim900 module for users to control the lights through the phone [2] The account also shows the importance of energy storage and environmental protection.

In conclusion, our team decided to carry out the thesis “Design of a solar model for controlling brightness levels of a LED system based on a light sensor” to create an automatic controller capable of optimizing the duration to use of solar lights.

1.2 RESEARCH OBJECTIVE

Design and construction of a controller for solar LED lights is using ESP8266 microcontroller as an electrical energy control processor to control the brightness of LED bulbs At the same time, it allows users to monitor parameters and the remaining voltage level in the reserve battery.

1.3 LIMITATION

The thesis has some limitations as follows:

The thesis uses conventional energy lamps sold in the market, so the circuit has not been standardized for diverse uses.

The system applies to rural areas, where solar lights are often used for lighting The system is not used in place where no internet connection.

1.4 RESEARCH CONTENT

This thesis of implementation includes the following contents:

Content 1: Refer to document, read and summarize to find the development

direction of the thesis.

Content 2: Block diagram design and description them.

Content 3: Design, calculate and connect module such as ESP8266, BH1750.Content 4: Hardware design and construction, actual circuit construction.Content 5: Write a program for the controller.

Content 6: Write the program to display a website.Content 7: Assemble and complete the module.

Content 8: Running and testing the system for completing.Content 9: Write a report.

Content 10: Prepare slides for defense.1.5 THESIS SUMMARY

Chapter 1: Introduction

This part introduces the reasons for choosing the topic, the objectives, and limitations of the research, the research contents and presents the layout of the research thesis.

Chapter 2: Background

This section presents the basic theory, the parameters of the components as a premise to implement the thesis, using the researched topics as the basis for reference.

Chapter 3: Calculation and design

This chapter presents the calculation of the system construction and website design to display information based on the theory

This chapter presents the results, images of models, and data collected during the implementation of the thesis, comments on the thesis and future development direction of the thesis

Chapter 6: Conclusion and future work

In this section, we present the conclusions and directions of this thesis.

CHAPTER 2 LITERATURE REVIEW 2.1 SOLAR ENERGY EXPLOITATION AND PRODUCTS

When the solar panel system is widely used, the model of automatic rotation of solar panels is more applied The model can increase the efficiency of photovoltaic income for maximum and best power conversion.

Figure 2 1 The front of system model after completion

The model can help the solar panels to charge maximum energy, but it has disadvantages because of angular deviation due to Servo noise and low energy input to the model size [3]

2.1.2 Application of solar panel

In [4], the solar panel is used as a component to absorb light directly from the sun and convert it into electricity to help the public lighting system At the same time, the

device has the advantage of stable and durable operation.

Figure 2 2 Module of the system.

2.2 ENERGY-OPTIMIZING SYSTEMS 2.2.1 LEDs replace other lamps in application

There are a wide range of lights which are increasingly being used for different lightning purposes both indoors and outdoors In lighting systems, Light Emitting Diode (LED) is a new technology and is being developed continuously.

2.2.2 Pulse width modulation (PWM)

In the research [6], using PWM control at each cycle will reduce the load current-included distortion in the phase control circuit Also, at high switching frequencies, the maximum harmonics can be reduced by using a simple capacitance Total harmonic distortion can be minimized by using PWM Thus, authors have concluded that the PWM technique helps to improve power quality Moreover, out of all the PWM technique, SWPM is the best modifier.

Table 2 1 Comparision of PWH Techniques.

2.3 HARDWARE INTRODUCTION 2.3.1 A LED Chip 2835

Chip LEDs have a compact design of 2.8 x 3.5 x 0.7mm, have a typical forward voltage of 5V, maximum current of 240mA LEDs operate at 0.5W power, and test current at 150mA, have a temperature test of 25 degrees Celsius [8].

Figure 2 3 A LED chip 2835

2.3.2 Solar Panel

Currently, the using of solar batteries for green energy conversion is in high demand In topics [2], the author used solar batteries However, depending on the purpose of using, the panels have different sizes and parameters Therefore, solar panels are expensive compared to conventional rechargeable batteries, the using of solar panel can work in area where it is difficult to build electric power line or complex terrain.

2.3.3 Microcontroller ESP8266

In the thesis request, the team will use the ESP8266 module to be able to exchange information with the light sensor and send data to the database via WIFI The ESP8266 module is developed based on the ESP8266EX chip to meet the technical requirements in the Internet of things industry

2.3.4 Light intensity sensor BH1750

In the thesis [2], sensor BH1750 was used to collect data and information in light sensing Therefore, in this topic, my group chose to use the BH1750 sensor to collect data and information about sunlight intensity to calculate the ability to optimize the operating time of solar lights.

Calculation of the resistance when applying Ohm’s law is as follows:

Choose as 220Ω as appropriate.

For the LED panel output to work stably, we design the FET at the GND terminal to avoid the voltage drop on the FET from affecting the LED board Since the number of LEDs that used is 180 LEDs of 2835 SMD has an average current consumption of 60mA at 3V (according to the datasheet), so the total current through the FET is calculated:

c Design of switch circuit

The circuit is designed based on the digital signal by GPIO12 pin outputs (HIGH level is 3.3V, LOW level is 0V) The switch block has two measurement mode: measuring the voltage of the reserve battery and measuring the voltage of the PWM output.

Figure 3 4 Switch circuit

d Design of divider circuit

To measure the voltage of 3.3V with the ESP8266 microcontroller, we need to scale the value to 1V because the allowable scale of the ESP8266 is only from 0V to 1V So, the voltage divider bridge circuit need to be set up to use for measurement.

Figure 3 5 Schematic of divider circuit

e Design of source circuit

The main source of power is from batteries and solar panel In the thesis, a battery is used to supply power to LED and microcontroller that will be charge by solar panel.

f Principle of operation

The system designed in thesis works entirely with energy from the sun The power source for the systems is designed to include: a solar panel and a battery pack Specifically, the charging source includes charging with a solar panel 6V and power