Volumn 5



1, 2, 3 Students Electrical and Electronics Engineering,

Audisankara College of Engineering and Technology, Andhra Pradesh, India.

4 Assistant Professor Department of Electrical and Electronics Engineering,

Audisankara College of Engineering and Technology, Andhra Pradesh, India.


Background: This study proposed an efficient technique for eradicating the upsurge in the number of cases of roads accidents caused by excessive intake of alcohol by drivers on the Indian roads. Material and methods: This study developed a prototype alcohol detection and engine locking system by using an Arduino Uno microcontroller interfaced with an alcohol sensor along with an LCD screen and a DC motor to demonstrate the concept. The system uses MQ-3 alcohol sensor to continuously monitor the blood alcohol content (BAC) to detect the existence of liquor in the exhalation of a driver. By placing the sensor on the steering wheel, our system has the capacity to continuously check alcohol level from the driver’s breath. The ignition will fail to start if the sensors detects content of alcohol in the driver’s breath. In case the driver got drunk while driving, the sensor will still detect alcohol in his breath and stop the engine so that the car would not accelerate any further and the driver can park by the roadside. Results: Results from testing the proposed system adequately matched the requirements for starting a car’s engine once the level of alcohol detected in the breath of the driver is higher than the prescribed level permissible by law. Conclusion: Experimental results show that the alcohol sensor was able to respond quickly when alcohol is detected and also have the ability to operate over a period.  Keywords: MQ-3 Alcohol sensor, Arduino Uno ATmega328 microcontroller, Blood Alcohol Content (BAC), LCD.Alcohol driving is the leading cause of road accidents. Alcohol Detection requires the stopping vehicles and it manually scan the drivers breadth analyzers. In the system that allows a alcohol sensor with arduino board along with a GSM module to send message notification and LCD display to show alcohol is detected and it automatically lock the vehicle motor. Then the system first allows configuring the user’s numbers into the program. And the driver is drunk by alcohol above permissible limit sensed the input triggers by providing required voltage. Thus the system provides alcohol detection using engine locking through arduino incidents automatically.

KEYWORDS: Arduino UNO, MQ3 Alcohol Sensor, GSM module, DC motor, LCD Display.


Driving is a complex process that involves several perceptual and motor tasks • All over the world India bangs the top most positon in accidental deaths. Nearly 1.2 lakh of people killed every year on Indian roads • Rollover accidents are now responsible for almost 1/3 of all highway vehicle occupant fatalities • Rollovers tend to be more serious than other types of accidents. For light trucks and SUVs the percentage of occupant fatalities associated with rollovers is about 50%. For heavy trucks the number is about 60%.The common causes for vehicle accidents are driver distraction or negligence, urban location-heavily populated areas or small areas with insufficient transport facilities, vehicle handling problem and weight distribution problem. Accident in road curve mainly occurs when the centrifugal force is more than the direction and momentum force which makes the vehicle to move in a straight line instead of curved path

Fig 1. Indian roads.

Under estimation of speed in curved roadways may be a contributing factor necessitating speed adjustment and thus causing fatal and serious injury accidents in curves especially in heavy vehicles. • As the result of approaching sharp curves without realizing that current speed is dangerous to passing through the curve, when driver fails to decelerate while just realizing that, the driver feels a tense moment and traffic incidents may occur.while taking a curve three types forces are involved they are directional force momentum force and centrifugal force. Centrifugal force comes into play when you’re rounding a curve. It tends to pull your vehicle out away from the inside edge, regardless of which direction you’re traveling. • If a car on the “inside” lane of a curvetries to navigate with too much speed, centrifugal force will pull it away from the center and potentially, into the path of oncoming traffic. Or, if a car is travelling with too much speed from the other direction–in the “outside” lane of a curve–centrifugal force will pull it out to the right and off the roadway. We hear lot of accidents due to drunk driving and it will not be in stable condition. So it rash driving is the in convenience for other road death for the drunk driver and not for others. In this system uses a compact arduino Uno board. Programs are developed in embedded C. The main purpose for this project is “Automatic Engine Locking System Through Alcohol Detection using Arduino”. Most of these days many accidents are happening became of the alcohol detection of the driver or the person who is in the vehicle. Almost all the countries in the world are facing major accidents because of Drunk & Drive. In this project is designed for safety of the people seating the vehicle. Our prototype system, integrates the following hardware components in the design: An LCD, the MQ-3 alcohol sensor, DC motor, Buzzer and two LEDs are integrated to ATmega328 microcontroller. The proposed system was designed and simulated using Proteus VSM simulator. The software code to be burnt into the Arduino board was written in Arduino IDE sketch.  Many research efforts have been directed to the design of efficient systems that will monitor drink-driving. Altaf et al.


Now a day’s road accident is a major problem all over the world. After reviewing the literature survey in the previous section it was clear that the more number of accidents was mainly because of drunk drivers, driving under the influence of alcohol, which is responsible for about one-third of all road accidents. Every year people are injured or killed on the road because another driver was driving under the influence of alcohol & the alcohol impairs human beings ability to determine distance, reaction time, judgment and vision. None of the advance technique in vehicles detects alcohol consumption in drivers.   In this proposed system uses MQ3 alcohol sensor with arduino along with GSM module to send message notification for users numbers and LCD Display to identify the alcohol is detected or not and DC motor to sensed by the alcohol and it automatically stop the motor. And the system check the permissible limit then the sensor will be triggered the processor about the respective voltage. Thus the system will automatically stop the motor and it send message to the users.

The block diagram of the proposed system is shown in figure 1. It consists of power supply section, MQ-3 alcohol sensor, DC motor, LCD, microcontroller, alarm and LEDs. The various units were designed and tested separately.

Fig. 2: Block diagram of Alcohol detection of drunk drivers with automatic car engine locking system


 Power Supply Unit                                         

Our system is powered with a 9V battery. A 5V DC supply as required by the microcontroller, sensor and display unit. While other components like DC motor require 1.5V and the LEDs need 2V. The Arduino Uno board has already been designed to operate without the use of transformer, the system can be powered via the USB connection from computer or with an external power supply of 7 to 12V. The External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. Any voltage that is above 12V will make the control device to burn thereby destroying the board. It is advisable to use voltage between 7 – 12V. 

MQ-3 Alcohol Sensor Unit

The sensor is made of Tin Dioxide (SnO2) sensitive layer. The sensor is configured with a high sensitivity to alcohol and small sensitivity to Benzene. It has a simple drive circuit with fast response, stability, and long life. It has an analog interface type. On the sensor, port pins 1, 2 and 3 represents the output, GND and VCC respectively.

Fig 3: Alcohol sensor

LCD Display

Unit LCD display is used for displaying the message sent from the remote location. The LCD module (Fig. 5) displays alphanumeric, kana (Japanese characters) and symbols. It consists of 16 pins (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 display power rating is as stated below

Current (𝐼𝐷𝐷) (𝑉𝐷𝐷=5.0𝑣)………….1.0𝑚𝐴 − 3.0𝑚𝐴 𝑚𝑎𝑥 Range of 𝑉𝐷𝐷−𝑉0……………….1.5~5.25𝑉 𝑜𝑟 5.0±0.25

Fig. 4: 16×2 LCD display unit   

Alarm and Indicating Unit The alarm unit used is a buzzer which indicates when alcohol is detected. The buzzer used belongs to the PS series. The PS series are high-performance buzzers that employ Uni-morph piezoelectric elements and are designed for easy incorporation into various circuits. They have very low power consumption in comparison to electromagnetic units. It has a voltage requirement of 2V and is connected to pin 10 of the microcontroller. The standard resistor value of 220 Ω commercially available is closest to the computed value of 250 Ω, so a 220 Ω resistor was used to limit the current going through the LEDs.

ATmega328 Microcontroller Unit

The proposed system is built around ATmega328 Arduino Uno microcontroller board.  The unit consists of 14 pins which allows inflow and outflow of feeding (it is possible to use 6 of those pins as Pulse Width Modulation signal outputs), 6 continuous signal with time changing quantity, 16 megahertz electronic oscillator, a Universal Serial Bus port, a power connector, an on-board voltage regulator, ICSP header, and a reset button. The Atmega328 has 32 KB flash memory, 2 KB SRAM and 1 KB EEPROM. 

Fig. 4: Arduino Uno ATmega328 microcontroller unit

DC Motor

The DC motor is an electric DC motor used to demonstrate the concept of engine locking. Here in this work, the DC motor will be connected to pin 9 on the microcontroller, when alcohol is detected the DC motor stops in other to indicate that alcohol is detected and continue running when there is no alcohol detected.

Fig 5 : DC Motor

System Operation

The detected analog voltage values are read by the microcontroller; the Arduino Uno board contains 8 channels, 10-bit device that changes an analog voltage on a pin to a digital number. The system will link input voltages from 0-5V with values from 0-1023V to generate 5Vs for every 1024 units. The system will process the analog signal and convert it to digital value of 0 or 1.  Also, the analog values from the alcohol sensor will be scaled to percentage, and this percentage is equivalent to the analog voltage values in ppm (part per million). The first condition is the intoxication stage; the second condition is the slightly drunk stage and the last stage is drunkenness stage. Each stage will be a condition to perform a task based on the level of alcohol. In the intoxication stage, the LED indicator will be activated only, the alarm will be OFF and the car engine will be ON. In stage two, the alarm and the green LED indicator will be ON, as well as the car engine. Finally, the driver is mentally and physically inactive in stage three, so the engine will be OFF while the alarm and red LED will be ON. Therefore, once the system detect alcohol in stage three the car will be stopped and the driver can park by the roadside

System Flow chart

The flow chart of the system is shown in figure 6. The system algorithm comprises of three main steps. First is to boot up the system, next is the measuring state, this stage measure the amount of alcohol level from the drivers. A prescribed set limit will be given as input to the microcontroller, once the alcohol level exceeds the limit the car will not start. 

STEP 1: Power on the system

STEP 2: checks for alcohol concentration

STEP 3: if alcohol is detected

STEP 3.1: turn off car engine

STEP 4: Else

STEP 5: Car engine running

STEP 6: Go to step 1

Fig. 6: Flowchart of the entire system


The software design consists of a free running program which manipulates input from the Alcohol sensor and programming of the indicating unit, LCD display, DC motor, alarm unit. The program code is written on Arduino sketch and uploaded to ATMEGA328 microcontroller program memory using Arduino Uno development board. The hex file is generated using the Arduino sketch IDE environment. Figure 7 shows the device programming used for this research

Fig. 7: Device Programming

System Design and Simulation

After generating the hex file from the Arduino sketch environment, the hex file was copied from the Arduino file directory and linked to the Proteus for simulation. Each unit was also tested to ensure continuity and efficiency in the components before soldering. Figure 8 shows the full simulation design of our proposed system. Also, the location of hex file is depicted in figure 13. • Indicating unit Two LEDs with different colors are used. The green LED indicate when the engine is running and also notify the driver that his alcohol level is below the limit, and the other red LED indicate when there is alcohol detected and also when the engine is not running.              

Alarm unit

The alarm unit used a buzzer to produce sound whenever alcohol is detected. The purpose of the buzzer was to create awareness to passengers whenever alcohol is detected. The alarm unit

Engine locking unit

The engine locking unit was built by the concept of using a DC motor to demonstrate as the car engine. The DC motor operate based on preset conditions; once the alcohol level goes above 40% the engine motor stops. The engine motor continues to run when the alcohol level goes below 39%. The DC motor is connected to pin 9 on the microcontroller and it operate from 1.5V TO 6V.

Fig. 8: Engine locking unit

Alcohol checking stage

In this stage, when the car is switched on the system measures the level of alcohol from the driver breath to check whether the driver is intoxicated, slightly drunk and whether if he is extremely drunk. Based on this, the microcontroller only locks the engine when the level exceeds 40% in which case car engine stops so that the driver can manage to stare the car to the road side. The unit for measuring alcohol level is depicted

Alcohol detection unit

The alcohol sensor unit has four pins; test pin, vcc, dout and ground. The test pin is used to accept logic signals of 0 or 1 by using logic state pin as shown in figure 9. The LED is used to show when the sensor detect alcohol. in the simulation, when the logic state is 1 the led goes on to indicate that alcohol is present and off to show the absence of alcohol.

The circuit diagram of our proposed alcohol detection system is in figure 9 below.

Fig. 9: Complete Alcohol detection and engine locking design

Results The results of our experiments are presented in figures 10, 11 and 12 Tables 1, 2 and 3.

Table 1: Alcohol sensor reading

Table 2: Sensitivity level characteristics

Table 3: Level of drunkenness

The graph in figure 10 shows the output voltages for alcohol detection in ppm obtained with the help of the above readings for different alcohol content samples. The response of the different samples is in parts per million (PPM) vs Alcohol Sensor Operating voltages in Volt.

Fig. 10: Response of ppm (In Percentage) via alcohol sensor output voltages value

Figure 11 shows the graph of the voltage level at which the detection point takes effect. At 2V the car engine stops running and continues running once the alcohol level falls below 2V.

Fig. 11: Alcohol detection point

The detection limit at which the sensor detects Alcohol from the driver is depicted in figure 11. Discussion We tested the sensor’s accuracy using a deodorant perfume to simulate its response to alcohol concentration level. To verify the functionality of our system, we employed breadboard, digital Multimeter, LEDs, Arduino sketch IDE, and Proteus VSM software. The final bread boarding of the entire system is shown in figure 12. Alcohol Sensor Accuracy Accuracy is the measurement of an instrument to give equivalent value to the true value or the quantity being measured. The accuracy can be related to the percentage error as Error = Actual reading – Experimental reading Percentage error =Error Actual reading × 100% ⁄ from the experimental results obtained as shown in table 5, Total percentage error for the whole table = 45%. Therefore, Overall percentage error = Total percentage /total sample reading = 45/20 = 2.25%. The average accuracy of the alcohol sensor used is obtained as Ave % accuracy = 100−2.25% = 97.75 %. Thus, our calculation above shows that the alcohol sensor is 97.75% accurate. Sensitivity Level Characteristics Table 3 shows the alcohol levels in ppm, voltage and percentage. The values in ppm correspond to the voltage and percentage

Fig. 12: serial plot of the detection limit

Our system displays the percentage alcohol level to the driver. The ppm values are the concentration level, that is, BAC level. The voltage values increase or decreases based on the resistance of the alcohol sensor. Using this table, the locking concept was achieved by programming instruction to the microcontroller to lock the car engine when the alcohol sensor reading is above 40%. The microcontroller uses the analog voltage values coming from the sensor to determine whether the sensor reading is above the set limit. In essence, once the microcontroller receives analog value above 2V, it automatically compares it with the preset limit, if it is not the same the engine will stop. Level of Drunkenness Experimental results were obtained based on the three pre-designated conditions for drunk driving. In intoxication stage, the car engine will be running as the driver can still control himself. Also in the slightly drunk state, the system will still allow the engine to run. Finally, in the drunken state, the driver will lose stability and cannot make decisions. In that case, the engine automatically locks off. Table 4 shows the level of drunkenness.

In the presence of alcohol from the breath of drivers and curtail the catastrophic effects it can have on peoples’ lives. The system was designed and implemented successfully via the use of Arduino Uno ATMEGA328 microcontroller and MQ-3 sensor. Experimental evaluation of the system showed that the alcohol sensor was able to deliver fast response when alcohol is detected. Also, the ability of the alcohol sensor to operate over a long time is a feature of the proposed system. 

Prevention System

Roll over prevention meter has a engine control unit in which all above sensors and camera (load sensor, speed sensor, displacement sensor & night vision cameras) are interfaced.

The function of the sensors are controlled by the engine control unit. This device gets activated when displacement sensor find a road curve ahead the vehicle and the information from the three sensors are processed by the engine control unit.

While taking curve the speed of the vehicle is more than the speed required for taking curve the engine control unit will automatically reduce the speed by decreasing the fuel flow rate supplied from the tank to the engine.

It also alerts the driver in form of LED lights and buzzers


We can implement heart rate pulse variability to find accurately identify the driving behavior of driver and to assist them we can implement GPS technology to find out the location of the vehicle

In future, this system can be extended to more applications. Driver’s drowsiness can result to lack of control of the vehicle and leads to accidents. If driver feels drowsy driver can’t control the vehicle, when the driver wakes. We can prevent this kind of accidents by using the braking system. The accidents can happened due to asleep state the driver is prevented using automatic breaking system by using eye blink sensor. The asleep can be sensed by the eye blink sensor and the blinking frequency is measured. If the driver is drowsy, then the system will give buzzer alert to driver and the speed of the vehicle is reduced.

To improve the rescue assistance in the accident spot, image processing can be used more effectively in order to determine the environmental factor with the exact location using GPS. This provides the latitude and longitude information about vehicle location through GSM. Vibration sensors are also fixed to measure the damage of the vehicle. Based on the frequency values, the damage condition of the vehicle is measured. If a vehicle has met accident, vibration sensor gives signal to the system and image is sent to the hospital server. Based on this ambulance rescue will be sent to defined location


An effective solution is provided to develop the intelligent System for vehicle which will monitor various parameters of vehicle in between constant time period and will sent data to the concerned persons. This is done by using platforms like Arduino, Sensor, DC motor, LCD display. The whole system has the advantage of small volume and high reliability .This system brings innovation to the existing technology in the vehicles and also improves the safety features hence providing to be an effective development in the automobile industry. In this paper, we proposed a method to sense the presence of alcohol from the breath of drivers and curtail the catastrophic effects it can have on peoples’ lives. The system was designed and implemented successfully via the use of Arduino Uno ATMEGA328 microcontroller and MQ-3 sensor. Experimental evaluation of the system showed that the alcohol sensor was able to deliver fast response when alcohol is detected. Also, the Ability of the alcohol sensor operate over a long time is a feature of the proposal system


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