DTMF BASED DC MOTOR CONTROL

INTRODUCTION

Our project is based on DC motor control using DTMF technology. In this project, the motor is controlled by a mobile phone that makes a call to the mobile phone attached to the robot. In the course of a call, if any button is pressed, a tone corresponding to the button pressed is heard at the other end of the call. This tone is called "Dual Tone Multiple-Frequency" (DTMF) tone. The robot perceives this DTMF tone with the
help of the phone stacked on the circuit connected to dc motor. The received tone is processed by the microcontroller with the help of DTMF decoder. The microcontroller then transmits the signal to the motor driver ICs to operate the motor. Use of a mobile phone for motor control can overcome limitations which
we faced in rf based technique. It provides the advantage of robust control, working range as large as the coverage area of the service provider, no interference with other controllers and up to twelve controls.
 In this project the motor, is controlled by a mobile phone that makes call to the mobile phone attached to
the circuit in the course of the call, if any button is pressed control corresponding to the button pressed is heard at the other end of the call. This tone is called dual tone multi frequency tome (DTMF) circuit receives this DTMF tone with the help of phone stacked in the robot.

ROOM LIGHT CONTROLLER WITH VISITOR COUNTER

This Project “Automatic Room Light Controller with Visitor Counter using Microcontroller” is a reliable circuit that takes over the task of controlling the room lights as well us counting number of persons/ visitors in the room very accurately. When somebody enters into the room then the counter is incremented by one and the light in the room will be switched ON and when any one leaves the room then the counter is decremented by one. The light will be only switched OFF until all the persons in the room go out. The total number of persons inside the room is also displayed on the seven segment displays. The microcontroller does the above job. It receives the signals from the sensors, and this

signal is operated under the control of software which is stored in ROM. Microcontroller AT89S52 continuously monitor the Infrared Receivers, When any object pass through the IR Receiver's then the IR Rays falling on the receivers are obstructed this obstruction is sensed by the Microcontroller.

BATTERY

An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery  in 1800 by Alessandro Volta, batteries have become a common power source for many household and industrial applications. Miniature cells are used to power devices such as hearing aids and wristwatches; larger batteries provide standby power for telephone exchanges or computer data centers.

A voltaic cell for demonstration purposes. In this example the two half-cells are linked by a salt bridge separator that permits the transfer of ions, but not water molecules.

A battery is a device that converts chemical energy directly to electrical energy. It consists of a number of voltaic cells; each voltaic cell consists of two half cells connected in series by a conductive electrolyte containing anions and cations. One half-cell includes electrolyte and the electrode to which anions  migrate, i.e., the anode or negative electrode; the other half-cell includes electrolyte and the electrode to which cations (positively charged ions) migrate, i.e., the cathode or positive electrode. In the redox reaction that powers the battery, reduction (addition of electrons) occurs to cations at the cathode, while oxidation (removal of electrons) occurs to anions at the anode. The electrodes do not touch each other but are electrically connected by the electrolyte. Many cells use two half-cells with different electrolytes. In that case each half-cell is enclosed in a container, and a separator that is porous to ions, but not the bulk of the electrolytes, prevents mixing.

ULTRA SONIC MOTOR

Ultrasonic motors are a new type of actuator. They are characterized by high torque at low rotational speed, simple mechanical design and good controllability. They also provide a high holding torque even if no power is applied. Compared to electromagnetic actuators the torque per volume ratio of piezoelectric ultrasonic motors can be higher by an order of magnitude. Recently various types of piezoelectric ultrasonic motors have been developed for industrial applications such as camera lens drive or as actuator in the head restraint of automobile seats. This report describes several types of piezoelectric ultrasonic motors. In the first part the working principle of the travelling wave motor is explained. In the second part other types of piezoelectric ultrasonic motors are described and classified with respect to the vibration modes and contact mechanisms used in their design. Finally some open problems in piezoelectric ultrasonic motor research are addressed.

MICRO AIR VECHILE

There has been recent interest in unmanned air vehicles with a largest linear dimension no greater than 6 inch Micro air vehicles (MAVs) are intended to operate in close proximity to a point of interest without being detected and should provide surveillance teams with critical information in a rapid-deployment urban-environment mission scenario.

Micro Air Vehicle is a small flight vehicle that uses lift-generating mechanism different from the mechanism used for larger aircraft. These machines are used to perform a variety of mission including reconnaissance, surveillance, targeting, tagging etc in hazardous locations and for bio-chemical sensing in defence sector. The design features and the configurations of MAVs are different from that of normal aircrafts. The speed of MAV is very low and the size is less than 38.10 cm length, width or height. MAVs are not the small versions of ordinary aircrafts but are affordable fully functional, military capable, small flight vehicles in a class of their own.The advantage of this special mechanism is that, it is having more lift compared to a fixed wing mechanism. Also it can increase the lift without increasing the vehicle speed. Since the proposed mechanism helps for lift generation and not for the full 3-d movement this model have not been used for more functions. The future work will be for designing for the forward motion and also for reducing the weight by using light materials.

REMOTE CONTROLLED ROBOT

1.  INTRODUCTION

We have seen many projects where a robot is controlled by a remote controller. Here we describe a robot that can be steered in any direction just like you drive your car. Wireless steering senses the motion and transmits corresponding instruction to control the robot through RF communication. The robot also has an obstacle detection and avoidance system implemented.   

1.1  Circuit and working

Fig shown below is the block diagram of the complete project. The movement of the steering is sensed by the accelerometer. The data from the accelerometer is processed by Arduino Uno board and corresponding instructions transmitted through the RF transmitter to control the robot. The robot receives the in-structions and the MCU section drives motors corresponding to in-structions received. Obstacle detectors sense any object in the way and intimate the mi-crocontroller to stop forward motion.

1.2 Wireless steering

It is built around Arduino Uno board (Board1), encoder HT12E (IC1), regulator 7805 (IC2), 433MHz RF transmit-ter module, accelerometer module and a few discrete components. Pins A0, A1, A2, A3, A4 and A5 of Board1 are connected to pins ST,

Z-axis, Y-axis, X-axis, GND and VCC of the accelerometer module, respectively.

1.3 Accelerometer module

An ac-celerometer is an electromechanical device that measures acceleration of anything that it is mounted on. The accelerometer module used here is based on ADXL335 triple-axis accelerometer from Analog Devices. The sensor has a full sensing range of ±3g.

1.4 Arduino Uno board

Arduino is an Open Source electronics prototyping platform based on flexible, easy-to-use hardware and software. It is intended for artists, designers, hobbyists and

anyone interested in creating interac-tive objects or environments. 

1.5 Robot

It comprises an RF receiver module, decoder HT12D (IC3), microcontroller PIC16F877A (IC4), operational amplifier LM324 (IC5), motor driver L293D (IC6), regulator 7805 (IC7) and a few discrete components.

1.6 Software

The wireless steering is built around Arduino Uno board. Arduino Uno is programmed using Arduino IDE software. ATmega328 on Arduino Uno comes pre-burnt with a boot loader that allows you to upload new code to it without the use of an external hard-ware programmer. It communicates using the original STK500 protocol. You can also bypass the boot loader and program the microcontroller through ICSP (in-circuit serial programming) header, but using boot loader programming is quick and easy. Select Arduino Uno from ‘Tools→Board’ menu (according to the microcontroller on your board) in Arduino IDE and burn the program through standard USB port in the computer. The source program for the robot is written in ‘C’ language and compiled using MPLAB IDE for the robot. Burn the hex code into the microcontroller using a suitable programmer. Program execution starts by initialising the input and output ports. The program checks the received data for forward, backward, left and right movements and gives correspond-ing control signals to the motor driver.

2. LITERATURE SURVEY

We have seen many projects where a robot is controlled by a remote controller. Here we describe a robot that can be steered in any direction just like you drive your car. Wireless steering senses the motion and transmits corresponding instruction to control the robot through RF communication. The robot also has an obstacle detection and avoidance system implemented.

The idea to this project initially was gathered from an article given in Electronics For You magazine February 2013 issue titled “Cars : Packed With Electronics from Boot to Botnet”. The article published on page 113 of the above mentioned magazine was titled “Robocar With Wireless Steering”.

Also the project includes various discrete components which required deep study of some components involved like arduino board, rf module, accelerometer and PIC microcontroller.

The arduino uno is an open-source prototyping platform which has various sources of study involving its official website “www.arduino.cc” and several forums associated with it. Also there are books being written by its founders that are “Beginning Arduino” by Michael McRoberts and “Getting Started With Arduino” by Massimo Benzi.

Detailed information about PIC microcontroller was gathered from its manufactureres’ site that is “ww1.microchip.com” in the form of datasheet.

Accelerometer is a latest device being used in most of the smartphones today. The accelerometer being used in the project is ADXL 335 manufactured by analog devices and its datasheet is also provided by analog devices ,

Various web articles were referenced which are being given in the refrences column at the end of this synopsis.

3 APPLICATIONS

3.1 In Military:

Wireless steering for military tanks and jeeps could serve as a great tool which could save life of military persons as they could be operated from a distance.

3.2 Automated Vehicles:

As one of the most successful applications of wireless steering, driverless vehicles have recently received significant attention, especially during the past several years. At least two reasons account for this trend: the first is the wide range of commercial applications, and the second is the availability of feasible technologies after 30 years of research.

3.3 Security and Monitoring Purposes:

Robocars with cameras can be developed for security and monitoring purposes by security agencies as well as home users.

3.4 In Children’s Toys :

Wireless Steering is easy to operate hence children will find it more easy and useful.

“TERAHERTZ WAVES AND ITS APPLICATION”

THESE DAYS, it is not possible to do justice to an entire field or give sufficient credit to all its deserving technical innovators in one short paper, even in a relatively narrow area of development like terahertz technology. If this were the case, we would not have such a plethora of journals to submit to, nor conferences to attend. One thing is certain, the IEEE  Microwave Theory and Techniques Society (IEEE MTT-S), through its journals and sponsored conferences, has played a major role in defining, distributing information on, and advancing the field of terahertz technology since the society’s inception a half-century ago. During the course of this paper, we look back to the infancy of modern terahertz technology, beginning where Wiltse so ably left off in1984.Terahertz Technology refers to the research and development of devices operating at terahertz (THz) frequencies, generally defined as 100GHz - 10THz. This essentially unexplored region of the electromagnetic spectrum has received much interest in recent years from both the scientific and corporate world because of the unique properties of THz waves. These unique properties are proving to be very beneficial for many scientific fields and very profitable for companies developing the technology for commercial use. The ’THz gap’ has been studied extensively since the 1980’s and many applications have been proposed particularly in recent years due to the rapid development of semiconductor materials, laser technology and photonics. This report will cover the current state of THz technology based on available literature. Additionally, analysis of the behaviour of the radiation and the technical aspects of the devices will be used to examine limitations on proposed applications and areas of potential research.

THz is very promising technology for many applications. This technology is now moving forward to commercialisation. Backward wave oscillator (BWO) is most successful tube for generating Tera Hertz. The only disadvantages of BWOs include the need for a large external magnetic field required for a highly stable high-voltage power supply. Pyrometer is the most successful detector used for detection of the objects. The cost of the THz imaging system is very high. Because of this reason, most developing countries cannot afford this. This motivates the researchers to carry out work in this field to bring down the cost of the equipment. In conclusion, present THz system has long distance to go before it can be commercially used all over the world.