HIGH SENSITIVE ALCOHOL SENSOR WITH AUTO CAR IGNITION DISABLE FUNCTION

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1 HIGH SENSITIVE ALCOHOL SENSOR WITH AUTO CAR IGNITION DISABLE FUNCTION K.S.SAI MANIKANTA SWARNANDHRA INSTITUTE OF ENGINEERING AND TECHNOLOGY,NARSAPUR ABSTRACT The main aim of this embedded application is to detect the alcohol drunken people. We are developing an embedded kit which will be placed in a vehicle. Now, the vehicle will be under the control of the kit.if any drunken person enter in to the vehicle it gives a buzzer sound immediately, and now the car will be under the control of the hardware used. At present drunken drivers have increased enormously and so is the deaths due to drunken drivers. The main reason for driving drunk is that the police are not able to check each and every car and even if they catch any one the police can be easily bribed. So there is a need for an effective system to check drunken drivers. In our alcohol detection system the ignition of the fuel is regulated by a sensor circuit. The sensor circuit is used to detect whether alcohol was consumed by the driver recently. Our design also consists of sensor which is used to check whether alcohol is consumed. The effects of drinking and driving are always risky and can often be lethal. The programming language used for developing the software to the microcontroller is Embedded/Assembly. The KEIL cross compiler is used to edit, compile and debug this program. Micro Flash programmer is used for burning the developed code on Keil in to the microcontroller Chip. Here in our application we are using AT89C52 microcontroller which is Flash Programmable IC. AT represents the Atmel Corporation represents CMOS technology is used for designing the IC. 26

2 Required Skill Set 8051 Architecture and Interfacing. Alcohol Sensor C Programming. DC Motor Hardware required Micro controller Alcohol sensor LCD ADC POWER SUPPLY L293d DC Motor Software tools Keil compiler Embedded C code 27

3 Block Diagram: 28

4 EMBEDDED SYSTEMS Introduction: An embedded system is a system which is going to do a predefined specified task is the embedded system and is even defined as combination of both software and hardware A general-purpose definition of embedded systems is that they are devices used to control, monitor or assist the operation of equipment, machinery or plant. "Embedded" reflects the fact that they are an integral part of the system. In many cases their embeddedness may be such that their presence is far from obvious to the casual observer and even the more technically skilled might need to examine the operation of a piece of equipment for some time before being able to conclude that an embedded control system was involved in its functioning. At the other extreme a general-purpose computer may be used to control the operation of a large complex processing plant, and its presence will be obvious. All embedded systems are including computers or microprocessors. Some of these computers are however very simple systems as compared with a personal computer. The very simplest embedded systems are capable of performing only a single function or set of functions to meet a single predetermined purpose. In more complex systems an application program that enables the embedded system to be used for a particular purpose in a specific application determines the functioning of the embedded system. The ability to have programs means that the same embedded system can be used for a variety of different purposes. In some cases a microprocessor may be designed in such a way that application software for a particular purpose can be added to the basic software in a second process, after which it is not possible to make further changes. The applications software on such processors is sometimes referred to as firmware. The simplest devices consist of a single microprocessor (often called a "chip ), which may itself be packaged with other chips in a hybrid system or Application Specific Integrated Circuit (ASIC). Its input comes from a detector or sensor and its output goes to a switch or activator which (for example) may start or stop the operation of a machine or, by operating a valve, may control the flow of fuel to an engine. 29

5 As the embedded system is the combination of both software and hardware Embedded System Software Hardware o ALP o C o VB Etc., o Processor o Peripherals o memory Block diagram of Embedded System Software deals with the languages like ALP, C, and VB etc., and Hardware deals with Processors, Peripherals, and Memory. Memory: It is used to store data or address. Peripherals: These are the external devices connected Processor: It is an IC which is used to perform some task Processors are classified into four types like: 1. Micro Processor (µp) 2. Micro controller (µc) 3. Digital Signal Processor (DSP) 4. Application Specific Integrated Circuits (ASIC) 30

6 Micro Processor (µp): It is an electronic chip which performs arithmetic and logical operations with assistance of internal memory. ALU CU MEMORY Micro Controller (µc): Block Diagram of Micro Processor (µp) It is a highly integrated micro processor designed for specific use in embedded systems. ALU CU Memory Block Diagram of Micro Controller (µc) 31

7 POWER SUPPLY: The input to the circuit is applied from the regulated power supply. The a.c. input i.e., 230V from the mains supply is step down by the transformer to 12V and is fed to a rectifier. The output obtained from the rectifier is a pulsating d.c voltage. So in order to get a pure d.c voltage, the output voltage from the rectifier is fed to a filter to remove any a.c components present even after rectification. Now, this voltage is given to a voltage regulator to obtain a pure constant dc voltage. 230V AC 50Hz D.C Output Step down transforme r Bridge Rectifi er Regulator Fig: Power supply Transformer:Usually, DC voltages are required to operate various electronic equipment and these voltages are 5V, 9V or 12V. But these voltages cannot be obtained directly. Thus the a.c input available at the mains supply i.e., 230V is to be brought down to the required voltage level. 32

This is done by a transformer. Thus, a step down transformer is employed to decrease the voltage to a required level. Rectifier:The output from the transformer is fed to the rectifier. It converts A.

8 This is done by a transformer. Thus, a step down transformer is employed to decrease the voltage to a required level. Rectifier:The output from the transformer is fed to the rectifier. It converts A.C. into pulsating D.C. The rectifier may be a half wave or a full wave rectifier. In this project, a bridge rectifier is used because of its merits like good stability and full wave rectification. The Bridge rectifier is a circuit, which converts an ac voltage to dc voltage using both half cycles of the input ac voltage. The Bridge rectifier circuit is shown in the figure. The circuit has four diodes connected to form a bridge. The ac input voltage is applied to the diagonally opposite ends of the bridge. The load resistance is connected between the other two ends of the bridge. For the positive half cycle of the input ac voltage, diodes D1 and D3 conduct, whereas diodes D2 and D4 remain in the OFF state. The conducting diodes will be in series with the load resistance R L and hence the load current flows through R L. For the negative half cycle of the input ac voltage, diodes D2 and D4 conduct whereas, D1 and D3 remain OFF. The conducting diodes D2 and D4 will be in series with the load resistance R L and hence the current flows through R L in the same direction as in the previous half cycle. Thus a bi-directional wave is converted into a unidirectional wave. 33

9 HARDWARE Hardware Modules: The Hardware modules of this project: Microcontroller Power Supply unit Motor Moisture sensor Microcontroller (AT89S52): Description of Microcontroller 89S52: The AT89S52 is a low-power, high-performance CMOS 8-bit micro controller with 8Kbytes of in-system programmable flash memory. The device is manufactured Atmel s highdensity nonvolatile memory technology and is compatible with the industry-standard 80C51 micro controller. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with in-system programmable flash one monolithic http; the Atmel AT89S52 is a powerful micro controller, which provides a highly flexible and cost effective solution to any cost effective solution to any embedded control applications to any embedded control applications. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next interrupt Or hardware reset. 34

10 MOtors DEFINITION Motor is a device that creates motion, not an engine; it usually refers to either an electrical motor or an internal combustion engine. It may also refer to: Electric motor, a machine that converts electricity into a mechanical motion o AC motor, an electric motor that is driven by alternating current Synchronous motor, an alternating current motor distinguished by a rotor spinning with coils passing magnets at the same rate as the alternating current and resulting magnetic field which drives it Induction motor, also called a squirrel-cage motor, a type of asynchronous alternating current motor where power is supplied to the rotating device by means of electromagnetic induction o DC motor, an electric motor that runs on direct current electricity Brushed DC electric motor, an internally commutated electric motor designed to be run from a direct current power source Brushless DC motor, a synchronous electric motor which is powered by direct current electricity and has an electronically controlled commutation system, instead of a mechanical commutation system based on brushes o Electrostatic motor, a type of electric motor based on the attraction and repulsion of electric charge o Servo motor, an electric motor that operates a servo, commonly used in robotics 35

o Internal fan-cooled electric motor, an electric motor that is self-cooled by a fan, typically used for motors with a high energy density WORKING OF DC MOTOR In any electric motor, operation is

11 o Internal fan-cooled electric motor, an electric motor that is self-cooled by a fan, typically used for motors with a high energy density WORKING OF DC MOTOR In any electric motor, operation is based on simple electromagnetism. A current-carrying conductor generates a magnetic field; when this is then placed in an external magnetic field, it will experience a force proportional to the current in the conductor, and to the strength of the external magnetic field. As you are well aware of from playing with magnets as a kid, opposite (North and South) polarities attract, while like polarities (North and North, South and South) repel. The internal configuration of a DC motor is designed to harness the magnetic interaction between a current-carrying conductor and an external magnetic field to generate rotational motion. Principle When a rectangular coil carrying current is placed in a magnetic field, a torque acts on the coil which rotates it continuously. When the coil rotates, the shaft attached to it also rotates and thus it is able to do mechanical work. 36

12 Every DC motor has six basic parts -- axle, rotor (a.k.a., armature), stator, commutator, field magnet(s), and brushes. In most common DC motors (and all that BEAMers will see), the external magnetic field is produced by high-strength permanent magnets 1. The stator is the stationary part of the motor -- this includes the motor casing, as well as two or more permanent magnet pole pieces. The rotor (together with the axle and attached commutator) rotate with respect to the stator. The rotor consists of windings (generally on a core), the windings being Electrically connected to the commutator. The above diagram shows a common motor layout -- with the rotor inside the stator (field) magnets. The geometry of the brushes, commentator contacts, and rotor windings are such that when power is applied, the polarities of the energized winding and the stator magnet(s) are misaligned, and the rotor will rotate until it is almost aligned with the stator's field magnets. As the rotor reaches alignment, the brushes move to the next commentator contacts, and energize the next winding. Given our example two-pole motor, the rotation reverses the direction of current through the rotor winding, leading to a "flip" of the rotor's magnetic field, driving it to continue rotating. In real life, though, DC motors will always have more than two poles (three is a very common number). In particular, this avoids "dead spots" in the commutator. You can imagine how with our example two-pole motor, if the rotor is exactly at the middle of its rotation (perfectly aligned with the field magnets), it will get "stuck" there. Meanwhile, with a two-pole motor, there is a moment where the commutator shorts out the power supply (i.e., both brushes touch both commutator contacts simultaneously). This would be bad for the power supply, waste energy, and damage motor components as well. Yet another disadvantage of such a simple motor is that it would exhibit a high amount of torque "ripple" (the amount of torque it could produce is cyclic with the position of the rotor). 37

Construction and Working Parts of a DC Motor Armature A D.C. motor consists of a rectangular coil made of insulated copper wire wound on a soft iron core.

13 Construction and Working Parts of a DC Motor Armature A D.C. motor consists of a rectangular coil made of insulated copper wire wound on a soft iron core. This coil wound on the soft iron core forms the armature. The coil is mounted on an axle and is placed between the cylindrical concave poles of a magnet. Commutator A commutator is used to reverse the direction of flow of current. Commutator is a copper ring split into two parts C 1 and C 2. The split rings are insulated form each other and mounted on the axle of the motor. The two ends of the coil are soldered to these rings. They rotate along with the coil. Commutator rings are connected to a battery. The wires from the battery are not connected to the rings but to the brushes which are in contact with the rings. 38

Brushes Two small strips of carbon, known as brushes press slightly against the two split rings, and the split rings rotate between the brushes. The carbon brushes are connected to a D.C. source.

14 Brushes Two small strips of carbon, known as brushes press slightly against the two split rings, and the split rings rotate between the brushes. The carbon brushes are connected to a D.C. source. Working of a DC Motor When the coil is powered, a magnetic field is generated around the armature. The left side of the armature is pushed away from the left magnet and drawn towards the right, causing rotation. 39

When the coil turns through 90 0, the brushes lose contact with the commutator and the current stops flowing through the coil. However the coil keeps turning because of its own momentum.

15 When the coil turns through 90 0, the brushes lose contact with the commutator and the current stops flowing through the coil. However the coil keeps turning because of its own momentum. Now when the coil turns through 180 0, the sides get interchanged. As a result the commutator ring C 1 is now in contact with brush B 2 and commutator ring C 2 is in contact with brush B 1. Therefore, the current continues to flow in the same direction. 40

16 41

17 PARAMETRS OF THE DC MOTRS 1. Direction of rotation 2. Motor Speed 3. Motor Torque 4. Motor Start and Stop Direction of Rotation A DC Motor has two wires. We can call them the positive terminal and the negative terminal, although these are pretty much arbitrary names (unlike a battery where these polarities are vital and not to be mixed!). On a motor, we say that when the + wire is connected to + terminal on a power source, and the - wire is connected to the - terminal source on the same power source, the motor rotates clockwise (if you are looking towards the motor shaft). If you reverse the wire polarities so that each wire is connected to the opposing power supply terminal, then the motor rotates counter clockwise. Notice this is just an arbitrary selection and that some motor manufacturers could easily choose the opposing convention. As long as you know what rotation you get with one polarity, you can always connect in such a fashion that you get the direction that you want on a per polarity basis. DC Motor Rotation vs Polarity 42

18 Applications and Advantages: Applications of Alcohol Detector in Car: 1) Alcohol Detector project can be used in the various vehicles for detecting whether the driver has consumed alcohol or not. 2) This project can also be used in various companies or organization to detect alcohol consumption of employees. Advantages of Alcohol Detector project: 3) Alcohol Detection System in Cars provides an automatic safety system for cars and other vehicles as well. Future Development: 1) We can implement GSM technology to inform the relatives or owners of the vehicle about the alcohol consumption. 2) We can implement GPS technology to find out the location of the vehicle. BIBLOGRAPGHY The 8051 Micro controller and embedded systems Muhammad Ali Mazidi Janice Gillispie Mazidi The 8051 Micro controller Architecture, Programming & Applications Kenneth J. Ayala Fundamentals of Micro processors and Micro computers B. Ram Micro processor Architecture, Programming & Applications Ramesh S. Gaonkar Electronic Components D.V. Prasad 43

19 References on the Web:

MANTECH ELECTRONICS. Stepper Motors. Basics on Stepper Motors I. STEPPER MOTOR SYSTEMS OVERVIEW 2. STEPPING MOTORS

MANTECH ELECTRONICS. Stepper Motors. Basics on Stepper Motors I. STEPPER MOTOR SYSTEMS OVERVIEW 2. STEPPING MOTORS MANTECH ELECTRONICS Stepper Motors Basics on Stepper Motors I. STEPPER MOTOR SYSTEMS OVERVIEW 2. STEPPING MOTORS TYPES OF STEPPING MOTORS 1. VARIABLE RELUCTANCE 2. PERMANENT MAGNET 3. HYBRID MOTOR WINDINGS