CIRCUIT DESIGN COLLECTS ENVIRONMENTAL PARAMETERS LCD DISPLAY

Introducing DHT11 temperature and humidity sensor DHT11 is a very common temperature and humidity sensor today.. Figure 2.3: DHT11 sensor arduinokit.vn  Pin out - VCC: Power Supply 3.

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION

FACULTY FOR HIGH QUALITY TRAINING

Major: ELECTRIC& TELECOMMUNICATION

Student ID: 17141026

Major: ELECTRIC& TELECOMMUNICATION

Advisor: DO DUY TAN, PhD

Ho Chi Minh City, June 2020

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION

FACULTY FOR HIGH QUALITY TRAINING

Major: ELECTRIC& TELECOMMUNICATION

Student ID: 17141026

Major: ELECTRIC& TELECOMMUNICATION

Advisor: DO DUY TAN, PhD

Ho Chi Minh City, June 2020

THE SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom– Happiness

1 Project title: CIRCUIT DESIGN GATHER OF ENVIRONMENTAL

PARAMETERS – LCD DISPLAY _

2 Initial materials provided by the advisor: _

3 Content of the project: _ Research major applications of sensors and circuits Thereby building systems of application of works in life and industry

4 Final product: _The divice to collect and display temperature and humidity

CHAIR OF THE PROGRAM

(Sign with full name)

ADVISOR

(Sign with full name)

THE SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom– Happiness

-Ho Chi Minh City, January 20, 2020 ADVISOR’S EVALUATION SHEET Student name: Student ID:

Student name: Student ID:

Student name: Student ID:

Major:

Project title:

Advisor:

EVALUATION 1 Content of the project:

2 Strengths:

3 Weaknesses:

4 Approval for oral defense? (Approved or denied)

5 Overall evaluation: (Excellent, Good, Fair, Poor)

6 Mark:……….(in words: )

Ho Chi Minh City, month day, year

(Sign with full name)

THE SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom– Happiness

-Ho Chi Minh City, January 20, 2020 PRE-DEFENSE EVALUATION SHEET Student name: Student ID:

Student name: Student ID:

Student name: Student ID:

Major:

Project title:

Name of Reviewer:

EVALUATION 1 Content and workload of the project

2 Strengths:

3 Weaknesses:

4 Approval for oral defense? (Approved or denied)

5 Overall evaluation: (Excellent, Good, Fair, Poor)

6 Mark:……….(in words: )

Ho Chi Minh City, month day, year

REVIEWER

(Sign with full name)

THE SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom– Happiness

-EVALUATION SHEET OF DEFENSE COMMITTEE MEMBER Student name: Student ID:

Student name: Student ID:

Student name: Student ID:

Major:

Project title:

Name of Defense Committee Member:

EVALUATION 1 Content and workload of the project

2 Strengths:

3 Weaknesses:

4 Overall evaluation: (Excellent, Good, Fair, Poor)

Name of project: CIRCUIT DESIGN COLLECTS ENVIRONMENTAL PARAMETERS LCD DISPLAY

Student’s ID: 17141026 Class: 17141CLA2

Email: 17141026@student.hcmute.edu.vn

Student’s ID: 17141032 Class: 17141CLA1

Email: 17141032@student>hcmute.edu.vn

Table of contents

CHAPTER 1 OVERVIEW

1.1 Reason choose the topic

1.2 Target the topic

1.3 Limit the topic

CHAPTER 2 THEORETICAL BASIS

2.1 Introducing arduino UNO R3

2.2 Introducing DHT11 temperature and humidity sensor 2.3 Overview of I2C communication

2.4 Overview of LCD 16×2

CHAPTER 3 CONSTRUCTION AND DESIGN

3.1 Block diagram and function of each block

3.1.1 Block diagram 3.1.2 Function 3.2 Detailed design

3.2.1 Source block 3.2.2 Sensor block 3.2.3 Control block 3.2.4 Communication block 3.2.5 Display block

CHAPTER 4 IMPLEMENTION

4.1 Hardware Design

4.2 Software Design

4.2.1 Algorithm flowchart 4.2.2 Program source code

CHAPTER 5 RESULTS AND CONCLUTIONS

5.1 Result

5.2 Development

5.3 Conclusion

REFERENCES

CHAPTER 1: OVERVIEW 1.1 Reason choose the topic

Nowadays, many factors affect the production process and people, in which temperature and humidity are also mentioned a lot, so the circuit for measuring temperature and humidity was borned With the development of current

technology, the production of simple temperature and humidity measuring circuit with high accuracy is quite simple The practical application is more common when the humidity plays a large role affecting people, goods, machines, etc

Temperature is used mostly in factories, warehouses and goods, maintenance of machinery and operating conditions In medicine, it is widely used in isolation rooms, treatment rooms for patients.

Therefore, we decided to carry out this project with the main function of displaying the temperature and humidity of the areas to be surveyed temperature and humidity With the title of the project " Circuit design gather of environmental parameters - LCD display ".

1.2 Target the topic

 The topic of development will be able to control the room temperature by automatically turning off the fan, air conditioner to open windows,

especially fire alarm and automatic fire extinguishing.

 Application in environmental weather monitoring Based on the change of ambient temperature and humidity over time to make predictions as well as appropriate measures for the experimental survey area.

 Research major applications of sensors and circuits Thereby building systems of application of works in life and industry.

1.3 Limit the topic

The topic only within the scope is Senior Design Project 1 so the actual efficiency as well as the accuracy of the circuit are not high.

CHAPTER 2: THEORETICAL BASIS 2.1 Introducing arduino UNO R3

Arduino Uno is built with the ATmega328P microcontroller core using quartz with a oscillation period of 16 MHz With this microcontroller, we have a total of 14 pin in / out (including 6 pin PWM) and an additional 6 pin receive analog signals marked from A0 - A5, these 6 pin can also be used as the normal input / output batteries.

Of the batteries mentioned, pin 13 is special because it connects directly to the status LED on the board On the board there is also a reset button, a lane connected to the computer via USB and a power supply port using a 2.1mm jack to get power directly from the AC-DC adapter or via a power battery.

In addition, the Arduino board also provides us with different batteries such

as 3.3V power supply battery, 5V power supply battery, GND battery

Figure 2.1: Arduino Uno R3 ( arduinokit.vn )

Arduino Uno R3 Specifications

Operating Voltage 5 Volts

DC Current per I/O

Figure 2.2: The detailed diagram of Arduino Uno R3 ( tapit.vn )

2.2 Introducing DHT11 temperature and humidity sensor

DHT11 is a very common temperature and humidity sensor today The sensor has a built-in signal preprocessor that helps data get accurate without having

to go through any calculations DHT11 sensor consists of 2 power pins, and 1 signal pin.

Figure 2.3: DHT11 sensor ( arduinokit.vn )

 Pin out

- VCC: Power Supply 3.5V to 5.5V

- GND: Connected to the ground of the circuit

- DATA: Outputs both Temperature and Humidity through serial Data

Operating voltage 3V - 5V (DC) Operating humidity range 20% - 90% RH, error ±5%RH Operating temperature range 0°C ~ 50°C, error ±2°C

Maximum sampling frequency 1 Hz

Maximum transmission distance 20m

Table 2.2: Specification of DHT11 sensor

2.3 Overview of I2C communication

I2C is the abbreviation of the English phrase "Inter-Integrated Circuit" It is

a communication protocol developed by Philips Semiconductors to transfer data between a central processor and multiple ICs on the same circuit board using only two signal paths I2C interface uses 2 wires to connect is SCL (Serial Clock) and SDA (Serial Data) In particular, SCL wire is used to synchronize between devices when transmitting data, while SDA is the data transmission wire.

Because of its simplicity, this type of protocol is widely used for

communication between microcontrollers and sensor arrays, display devices, IoT devices, EEPROMs, etc This is a type of synchronous serial communication protocol It means that data bits are transmitted bit by bit at regular intervals set by

a reference clock signal.

Figure 2.4: I2C communication ( arduinokit.vn )

Figure 2.5 The detailed diagram of Communication I2C ( academia.edu )

2.4 Overview of LCD 16×2

16×2 LCD display device (Liquid Crystal Display) is used in many

microcontroller applications LCD 16×2 has many advantages compared to other types of display such as: the ability to display diverse characters (letters, numbers, graphic characters); Easy to put into the application circuit according to various communication protocols, consuming very little system resources, low cost,

Figure 2.6: LCD 16×2 ( arduinokit.vn )

Stable operation: 2.7-5.5V 2.7-5.5V High output voltage > 2.4V

Power supply current 350uA - 600uA Operating temperature -30 - 75 degrees C

Table 2.3: Specification of LCD 16×2

Figure 2.7: The detailed diagram of LCD 16×2

CHAPTER 3 CONSTRUCTION AND DESIGN 3.1 Block diagram and function of each block

3.1.1 Block diagram

Figure 3.1: Block diagram of system

3.1.2 Function

 Functions of each block

- Source block: Provide power to the system.

- Sensor block: Read the temperature and humidity from the environment and then send the signal to the controller.

- Control Block: Receiving information from sensor and processing, then transmitted to the communication block.

Source Block (Power Supply)

- Communication block: Receive and process information from the control block and convert to LCD display.

- Display block: Displays the information that has been processed to LCD screen.

 The operation principle

For the system to work, the source block needs to provide enough power for the control block, sensor block, display block and communication block First, the sensor block operates based on the change in temperature and humidity of the environment When humidity changes, the substrate conductivity of the substrate in the sensor will change or the resistance between these electrodes will change Thereby receiving information and sending back to the control block via analog pins are connected together, the control block will be based on data from the sensor and process based on the converts digital signals After processing the temperature and humidity information, the communication block will transfer this information to the display block for display on the LCD.

ADC

DHT11 sensor

Peripher

al

factor

I2C

LCD display

I2C Communication

CHAPTER 4: IMPLEMENTION 4.1 Hardware design

Figure 4.1: Hardware design

and humidity

15mm x 12mm x 5.5mm

4.2.1 Algorithm flowchart

Receive data and transfer to

display

Collect temperature, humidity by DHT11

BEGIN

DISPLAY ON LCD

Processing the valuefrom

sensor

4.2.2 Program source code

#include <Wire.h>

#include <ds3231.h>

#include <liquidcrystal_i2c.h>

#include "DHT.h"

const int DHTPIN = 2;

const int DHTTYPE = DHT11;

clock.begin();

clock.setDateTime( DATE , TIME ); }

lcd.write(1);

lcd.print("C");

lcd.setCursor(11,1); lcd.print("H:"); lcd.print(round(h)); lcd.print("%"); }

delay(1000);

}

CHAPTER 5: RESULTS AND CONCLUTIONS 5.1 Result

5.2 Development

5.3 Conclusion

REFERENCES