ABSTRACT
An alcohol detector: - is a electronic device that detect alcohol in the breath of a person that has consumed the liquire. In this project, the design involved the hardware module and software module. The hardware module consist of sensor circuit (MQ – 3), the pic (Microcontroller circuit), the L.C.D. Circuit and the alarm circuit. The software module include, the programming on plc microcontroller that sends the information to the encoder using C – programming, the sensor detects the alcohol and then signal to the micro controller and display the result on the L.C.D upon the assembly. Then the buzzer alarm will start ringing, the alcohol detector is able to detect alcohol in the breath of the person.
TABLE OF CONTENT
Title page - - - - - - - - - - i
Certification page - - - - - - - - - ii
Dedication - - - - - - - - - - iii
Acknowledgement - - - - - - - - - iv
Abstract - - - - - - - - - - v
Table of content - - - - - - - - vi
CHAPTER ONE
1.0 Introduction - - - - - - - - - 1
1.1 Aim and objective - - - - - - - - 1
1.2 Scope of the study - - - - - - - - 1
1.3 Justification and significant of the study - - - - - 2
1.4 Mode of operation - - - - - - - - 2
1.5 Mode of design - - - - - - - - 2
CHAPTER TWO: LITERATURE REVIEW
2.1 Alcohol detector background - - - - - - - 8
2.2 Brief History on Alcohol detector - - - - - - 8
2.3 Infrared spectroscopy (intoxilyer) model - - - - - 9
2.4 The talking breathalzer mark - - - - - - - 10
2.5 MQ – 3 Gas Sensor - - - - - - - - 10
2.6 Alcohol in breath - - - - - - - - 13
2.7 Blood Alcohol concentration (BAC) - - - - - - 13
CHAPTER THREE
DESIGN AND CONSTRUCTION - - - - - - - 15
Sensor circuit - - - - - - - - - 18
Microcontroller - - - - - - - - - 18
Architecture of PIC 16f877 - - - - - - - - 18
LCD unit - - - - - - - - - - 23
LCD mode - - - - - - - - - - 23
LCD operating voltage - - - - - - - - 23
Regulated power supply - - - - - - - - 23
CHAPTER FOUR
Result and discussion - - - - - - - - 24
Result and testing - -- - - - - - - - 24
Software testing - - - - - - - - - 24
Hardware testing - - - - - - - - - 24
Pre implementation testing - - - - - - - - 25
Post – implementation testing - - - - - - - 25
Conclusion - - - - - - - - - - 25
Recommendation - - - - - - - - - 25
Reference - - - - - - - - - - 26
CHAPTER ONE
1.0 INTRODUCTION
This report presents the progress in using a alcohol detector, a device that senses a change in the alcoholic gas content of the surrounding air. The sensor will then analyse the amount of alcoholic vapors and offer the user some indication of the amount of alcohol present. Nowadays alcohol sensor plays a significant role in our society and it has vast application. This project detect the content of alcohol in the breath and thus it attempt to clap down alcoholic. This project use PIC16F877A, LCD display, MQ-3 alcohol sensor and buzzer. The output of the sensor is directly proportional to the content of alcohol consumed. We try to develop this project to make it available for everyone. This project won’t cost much, but it will bring much for it concentrate to humans safety. This project has a preventative effect which can stop accident from the beginning. In this project, initially we check whether the person id drunk or not by using the MQ-3 alcohol sensor. In this project sensor circuit is used to determine if a person has consumed alcohol or not. To this end, we have designed such a system that when alcohol is detect alarm is raised.
1.2 AIMS AND OBJECTIVES
The aims of this report is to design and construct an alcohol detector that sound alarm with the aid of buzzer.
- To design the power supply circuit
- To design and construct an alcohol detector which will detect alcohol in the breath through the MQ-3 sensor and pass the information to the micro controller and display the output through the L.C.D (Ayala, 8051).
1.3 SCOPE OF THE PROJECT
The Scope of study is to detects the content of alcohol in the breath and thus it attempts to clamp down alcoholics. This project include the following criteria: -
i. The study and application of MQ-3 sensor
ii. Architecture of PIC16F877A
iii. The PIC micro controller using C language programming
iv. The LCD display the buzzer alarm
v. The knowledge of soldering and soldering of electronics.
1.4 JUSTIFICATION AND SIGNIFICANT OF THE PROJECT
By completing this project: -
i. We can contribute to the world health improvement by using this alcohol detector to curb addicted drinking in people
ii. We can reduce road accident cause by drunk driver by testing the driver before during.
1.5 MODE OF OPERATION
The MQ-3 alcohol sensor is interfaced with micro controller which serves as the digital input signal to the controller. There is a LCD attached to output of the microcontroller that will function as a display. The MQ-3 sensor will analyse its content and consequently the sensor output voltage will go HIGH h5v).when output voltage is HIGH, input pains on the microcontroller will receive the information ad display the final result in a L.C.D display consequently the buzzer is sound, also when the input voltage of the alcohol sensor is LOW hov) the sensor will not detect alcohol and no alarm will raise (Mazidi, 2006).
The block diagram is show below.
1.6 MODE OF DESIGN
The design of this project can be outlined in four categories the sensor circuit, the microcontroller, the interfacing circuit and the power supply (Mazidi, 2006).
The sensor circuit is made up of MQ-3 sensor which consist, of four terminals. To connect the sensor, there are 4 leads. 2 of them are four power. The Sv terminal of the sensor connects into the positive terminal of the regulated power supply. The GND terminal of the sensor connects into the GND terminal of the regulated power supply and also PIC16F877A microcontroller. This establishes power for the sensor. The other 2 connections are the analogue input of the micro controller (Mazidi, 2006).
MICRO CONTROLLER
A microcontroller is used for controlling entire circuits and to maintain timing. There a microcontroller named PIC16F877A from microchip corporation is used for this purpose. It is a 16 bit microcontroller and has 40 pins arranged in five ports (Port A-E), the port B is used here for connecting LCD module and port A is used to interface with the input from the MQ-3 sensor.
As show in the above figure microcontroller is wired with a crystal for clock and each pin of crystal is connected to ground through capacitors to avoid noise pulse in the clock. Here a 4Mh2 Crystal is used that give 4Mh2 clock for microcontroller. A microcontroller internally consists of all features required for a computing system and functions as a computer without adding any external digital parts in it (Mazidi, 2006).
Liquid crystal display (L.C.D) is an electronic display module and is used for displaying the information sent by the microcontroller. The L.C.D module is a dot-matrix liquid crystal display that displays alphanumeric, and symbols. A 16 x2 LCD display is very commonly used in various devices and circuits. Most L.C.Ds with 1 controller has typins and LCDs with 2 controller has 16 pins h two pins are extra in both for backlight LED connections). Above is the quire simple schematic. It consists of 16pins (8 data lines, 3 control lines, 2 power lines, 1 contrast line and 2 pins for back light LED connection). Data line and control line are connected to the microcontroller. The LCD panels enable and resister select is connected to the control post the control port is an open collector/open drain output. When connecting LCD module to a parallel input devices, the burden of ensuring proper operation fallen the software. While most parallel ports have internal pull-up resistors there is a few which don’t. therefore by incorporating the two 10k external pull up register, the circuit is more portable for a wider range of computers, some of which may have no internal pull up resistors. At the interface of LCD module, there are three power supply terminal V-dd, GND, Vo. The LCD is driven by a voltage which is determine Vdd – vo. (Mazidi, 2006).
CIRCUIT DIAGRAM OF L.C.D
REGULATED POWER SUPPLY
Circuit diagram of regulated power supply
The circuit diagram of the regulated power supply unit is shown above. It mainly consist of a voltage regular (7805), capacitors, transformer, four diodes.
The voltage regular plays an important role in a power supply unit. Output of the power supply unit is always D.C which is given to the controller. The primary purpose of purpose of the regular is to provide a constant 5v regulated D.C voltage to the device.
BLOCK DIAGRAM OF ALCOHOL SENSOR USING MQ-3 SENSOR
DEFINITION OF SOME TERMS
Register: it represent a given amount of resistance in a circuit. Resistance is a measure of how the flow of electric current is opposed or resisted. It is define by ohm’s law which says the resistance equals the voltage divided by current.
Capacitor: it represent the amount of capacitance in a circuit. The capacitance in a circuit. The capacitance is the ability of a component to store an electrical charge.
Inductors: It represents the amount of inductance in a circuit. The inductance is the ability of a component to generate electromotive force due to a charge in the flow of current.
Transistor: is a there terminal device in which a voltage applied to one of the terminals (called the base) can control current that flows across the other two terminal called (the collector and the emitter)
Voltage regulator: the purpose of the voltage is to provide a constant output that is practically independent on the variation of: input voltage, output load current and temperature.
Strip board: These are used in the design and development of circuits. This method allows design alternation to be incorporated readility.
Conductor: is an component that allow the flow of an electrical current i one or more directions,.
