Chapter 1: INTRODUCTION
Almost all machines in industries are operated using electrical motors. Among them most of the motors are DC motors. DC series motor is specially used for traction, electric locomotive, trolley systems, crane and conveyer belt. All these works require frequent speed control for the preparation of job. We could gear the motor for the proper speed, but this is usually beyond scope of what we can accomplish in the basement workshop or we could measure the current that the motor draws and determine a series resistor value according to ohms law to insert to “drop” the motor supply voltage and slow the motor down. The problem with this approach is that if load on the motor increases, the motors operating current also increases, creating a larger voltage drop across that series resistor and supplying less voltage to the motor terminals when it is needed the most. This “vicious circle” usually results in the motor stalling at high load conditions. So what we need is a controller that will give the motor a kick of supply voltage for a variable amount of time to achieve the proper speed without the series dropping effect. A PWM (Pulse width modulation) wave can be used to control the speed of the motor.

CHAPTER 2 WIRELESS COMMUNICATIONS
Wireless communication is the transfer of information over distance without the use of electrical conductors or “wire”. The distances involved maybe short (a few meters as in television remote control) or long (thousands or millions of kilometers for radio communications). Wireless communication is generally considered to be a branch of telecommunications.

It encompasses various types of fixed mobile and portable two way radios, cellular telephones, personal digital assistants (PDAs) and wireless networking. Other examples of wireless technology include GPS units, garage door openers and or garage doors, wireless computer mice, keyboards and headsets, satellite television and cordless telephones.

Wireless operations permit services such as long range communications that are impossible or impractical to implement with the use of wires. The term is commonly used in telecommunications industry to refer to telecommunication systems (e.g. radio transmitters and receivers, remote controls, computer networks, network terminals, etc) which use some form of energy (e.g. radio frequency, infrared, laser light, visible light, acoustic energy, etc.) to transfer information without the use of wires. Information is transferred in this manner over both short and long distances.

In 1895 Marconi open the way for modern wireless communication by transmitting the three dot morse code for the letter ‘S’ over a distance of three kilometers using electromagnetic waves. From this beginning wireless communication has developed into a key element of modern society. From satellite transmission, radio and television broadcasting to the now ubiquitous mobile phones, wireless communications has revolutionized the way societies functions.

Wireless communication and the economic goods and services that utilize it have some special characteristics that have motivated specialized studies. First wireless communications relies on a scarce resource namely radio spectrum. Second use of spectrum for wireless communication required the development of key complementary technologies: especially those allowed higher frequencies to be utilized more efficiently. Finally because of its special nature the efficient use of spectrum required the coordinated development of standards. Those standard intern played a critical role in the diffusion of technologies that relied on spectrum use.

Wireless networking (i.e. the various types of unlicensed 2.4GHz WiFi devices) is used to meet many needs. Perhaps the most commonly use is to connect laptop users who travel from location to location. Another common use is for mobile networks that connect via satellite. A wireless transmission method is logical choice to network a LAN segment that most frequently change locations. The following situations justify the use of wireless technology: * To span a distance beyond the capabilities of a typical cabling * To provider backup communications link in the case of normal network failure * To link portable or temporary workstations * To overcome situations where normal cabling is difficult or financially impractical or * To remotely connect mobile users or networks.

The term “wireless” came into public use to refer to a radio receiver or transceiver (a dual purpose receiver and transmitter device) establishing it's usage in the field of wireless telegraphy early on. Now the term is used to describe modern wireless connections such as in cellular networks and wireless broadband internet. It is also used in a general sense to refer to any type of operation that is implemented without the use of wires such as “wireless remote control” or “wireless energy transfer” regardless of the specific technology (e.g. radio, infrared, ultrasonic) used.

2.1 Principles of wireless communication
Wireless communication begin with a message that is converted into an electronic signals by a device called transmitter. There are two types of transmitters analog and digital. An analog transmitter sends electronic signals as modulated radio waves. The analog transmitter modulates the radio waves to carry the electronic signals and sends the modified radio signals through space. A digital transmitter encodes electrical signals by converting messages into a binary code, the series of zeroes and ones that are the basics of all computer programming. The encoded electronic signal is sent as a radio wave. Devices known as receivers decode or demodulate the radio waves and reproduce the original message over a speaker.
Wireless communication system involve either one way transmission in which a person merely receives notice of message, or two way transmissions such as a telephone conversation between two people. An example of a device that only receives one way transmission is a pager which is a high frequency radio receiver. When a person dials a page number the pager company sends a radio single to the desired pager. The encoded signals triggers the pager circuitry and notifies the customer caring the pager of the incoming call with a tone or vibration.
Two way transmission requires both a transmitter and a receiver for sending and receiving the signals. A device that functions as both receiver and transmitter is called transceiver. 2.2 Types of Wireless Communication
Types of Wireless Communications are; * Infrared Wireless Transmission * Broadcast Radio * Microwave Radio * Communication Satellites * Microwave Radio 2.3 Applications : 1. Broadcasting services 2. Mobile communications of voice and data 3. Fixed Services 4. Satellite 5. Professional LMR 6. Consumer Two way Radio including FRS (Family Radio Service), GMRS (General Mobile Radio Service) and CB(Citizens Band) radios. 7. Consumer and professional marine VF radios 8. Cellular telephones and pagers 9. Global Positioning System (GPS) 10. Cordless computer peripherals 11. Cordless telephone sets 12. Satellite Television 13. Wireless Gaming 14. Security Systems 15. Television Remote control 16. Cellular telephony 17. Wi-Fi 18. Wireless Energy Transfer 2.4 Advantages of Wireless Communication * Anywhere, Anytime Work. * Through wireless communication, working professionals and mobile workers can work and access internet just about anywhere, anytime without the hassles of wires and network cables. * Enhanced productivity. * Workers ,students, professional and other need not to constrained by wired internet connections or dial up connectivity .Wireless internet connectivity options ensures that work and assignments can we completed anywhere and enhance overall productivity of all concerned. * Remote area connectivity, * Workers doctors and other professionals working in remote location hospitals and medical centers can keep in touch with anyone through wireless communication. Nonprofit organization volunteers working in remote and underserved areas can stay connected to the outside world with the help of wireless communication. * On demand entertainment bonanza. * For those unable to keep away from their daily soap operas, reality programs, online tv shows and internet surfing or download activities, wireless communications ensures an entertainment bonanza on demand and anytime. * Emergency alerts. * Through wireless communication, many emergency situations and crisis situations can be addressed quickly. Help and other assistance can reach affected areas quickly through early alerts and warnings provided with the help of wireless communication.

2.5 Disadvantages if wireless Communication * Wireless communications limited by range of transmitters.

* Cost of wireless communication system and components are high.

* When transmitting data, users must sometimes send smaller bits of data so the information moves more quickly. The size of devices that accessing the information is also still an issue.

* Many applications need to be a reconfigured if they are going to be used through wireless connections.

* Most client/server applications rely on persistent connections which is not the case with wireless.

* Since radio waves travels through atmosphere they can be disturbed by electrical interference is (such as lightning) that causes static.

CHAPTER 3 RF TECHNOLOGY
3.1 INTRODUCTION
Radio frequency (RF) transmitters are widely used in radio frequency communications system. With the increasing availability of efficient, low cost electronic modules, mobile communication system are becoming more and more widespread. A terminal apparatus used in the radio communications system receives a radio frequency signal transmitted from a base station, by an antenna, inputs the signal to a receiving radio-frequency unit via an antenna duplexer, high frequency amplifies the signal, removes unnecessary waves outside the receiving band from the signal, converts the signal to an intermediate frequency signal, demodulates the intermediate frequency signal by a demodulator, and converts the signal into a base band signal. Generally, a radio transmitter is used for performing a radio transmission operation, whereby a high frequency signal outputted from a modulator is transmitted to an antenna of the radio transmitter and is transmitted there from to a remote radio transmitter thereby a signal is transmitted. The transmitting base band signal is subjected to a predetermined signal process, input to a modulator, which modulates a carrier wave signal. The modulated carrier wave signal is converted into a radio frequency by a transmitting radio-frequency circuit and amplified to a predetermined transmitting power, and transmitted to the base station from the antenna via the duplexer. Communication systems are known to support wireless and wire lined communications between wireless and /or wire lined communication devices.
The function of a radio frequency (RF) transmitter is to modulate, up convert, and amplify signals for transmission into free space. An RF transmitter generally includes a modulator that modulates an input signal and a radio frequency power amplifier that is coupled to the modulator to amplify the modulated input signal. The radio frequency power amplifier is coupled to an antenna that transmits the amplified modulated input signal. Power amplifiers are required in radio telecommunication system to amplify signals before transmitting, because a radio signal attenuates on the radio path.

3.2 Advantages of RF technology * No line of sight is required. * Not blocked by common materials. It can penetrate most solids and pass through walls. * Longer range. * It is not sensitive to light. * It is not much sensitive to the environmental changes and weather conditions. 3.3 Disadvantage of RF technology * Interference: communication devices using smaller frequencies –wireless phones, scanners, wrist radios and personal locaters can interfere with transmission. * Lack of security: easier to “eavesdrop” on transmission since signals are spread out in space rather than confined to a wire. * Higher cost than infrared. * Federal communications (FCC) licenses required by some products. * Lower speed: data rate transmission is lower than wired and infrared transmission.

CHAPTER 4 COMPONENTS AND BLOCK DIAGRAMS
Table 4.1 List of Components S. No. | Equipment | Range/Type | Quantity | 1 | Transformer | 230/9V Center tapped Transformer | 1 | 2 | Diodes | IN4007 | 8 | 3 | Capacitor | 1000µF,35 V | 1 | 4 | Voltage Regulator | LM 7805 | 2 | 5 | Push Button | | 4 | 6 | Motor Driver | LM293D | 1 | 7 | Encoder | HT12E | 1 | 8 | Decoder | HT12D | 1 | 9 | LEDs | | 9 | 10 | Resistors | 15k/2w33k/2w | 113 | 11 | DC Motor | | 1 | 12 | Transmitter-Receiver | STT433MHz | 1Pair | 13 | Antenna | | 1 | 14 | Bread board | | 2 |

4.1 Proposed Block Diagram

Fig. 4.1 Block Diagram of Power Supply

Fig. 4.2 Circuit diagram of power supplies

This section consists of rectifier filter and voltage regulator. Center tapped transformer is used which step down 230 volts into 9 volts. This output of transformer is fed to bridge rectifier which converts it into pulsating DC. Bridge rectifier is used because of its merits like good stability and full wave rectification. Capacitive filter used here smoothen the DC by removing ripples. Regulator IC 7805 is used here at output stage to maintain constant voltage of 5 volts.

Fig. 4.3 Block Diagram of Transmitter Unit
This section consists of encoder HT12E. Rf transmitter STT 433MHz, 9V battery voltage regulator switches and antenna. The switches are placed at encoder side. Encoder works as DAC and this analog signal is given to transmitter. Transmitter sends this information through EM waves (RF) to receiver station. Switches used here are manually operated. The analog signal is transmitted serially.
The following table shows some example of motor operation with different switch combinations. Switch 1 | Switch 2 | Switch 3 | Switch 4 | Motor Operation | 1 | 0 | X | X | Forward Direction | 0 | 1 | X | X | Reverse Direction | 0 | 0 | X | X | OFF | 1 | 1 | X | X | OFF | X | X | 1 | 0 | Medium Speed | X | X | 0 | 1 | High speed |

Fig. 4.4 Block Diagram of Receiver Unit And Driver
Receiver section consists of receiver STT 433MHz, 5V.
HT12D decoder decodes the analog signal to digital signal and this data is collected for the microcontroller. Microcontroller gives command to H-bridge which is connected to motor.
Fig. 4.5 Flow of control signals from switches to MCU.

CHAPTER 5 MICROCONTROLLER
5.1 The Arduino UnO
The Arduino Uno is a microcontroller board based on the ATmega328. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to get started.
The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB-to-serial converter.

5.2 Summery Microcontroller | ATmega328 | Operating Voltage | 5V | Input Voltage (recommended) | 7-12V | Input Voltage (limits) | 6-20V | Digital I/O Pins | 14 (of which 6 provide PWM output) | Analog Input Pins | 6 | DC Current per I/O Pin | 40 mA | DC Current for 3.3V Pin | 50 mA | Flash Memory | 32 KB (ATmega328) of which 0.5 KB used by bootloader | SRAM | 2 KB (ATmega328) | EEPROM | 1 KB (ATmega328) | Clock Speed | 16 MHz |

5.3 Features:
• High Performance, Low Power AVR® 8-Bit Microcontroller
• Advanced RISC Architecture
– 131 Powerful Instructions – Most Single Clock Cycle Execution
– 32 x 8 General Purpose Working Registers
– Fully Static Operation
– Up to 20 MIPS Throughput at 20 MHz
– On-chip 2-cycle Multiplier
• High Endurance Non-volatile Memory Segments
– 4/8/16/32K Bytes of In-System Self-Programmable Flash progam memory
(ATmega48PA/88PA/168PA/328P)
– 256/512/512/1K Bytes EEPROM (ATmega48PA/88PA/168PA/328P)
– 512/1K/1K/2K Bytes Internal SRAM (ATmega48PA/88PA/168PA/328P)
– Write/Erase Cycles: 10,000 Flash/100,000 EEPROM
– Data retention: 20 years at 85°C/100 years at 25°C
– Optional Boot Code Section with Independent Lock Bits
In-System Programming by On-chip Boot Program
True Read-While-Write Operation
– Programming Lock for Software Security
• Peripheral Features
– Two 8-bit Timer/Counters with Separate Prescaler and Compare Mode
– One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture
Mode
– Real Time Counter with Separate Oscillator
– Six PWM Channels
– 8-channel 10-bit ADC in TQFP and QFN/MLF package
Temperature Measurement
– 6-channel 10-bit ADC in PDIP Package
Temperature Measurement
– Programmable Serial USART
– Master/Slave SPI Serial Interface
– Byte-oriented 2-wire Serial Interface (Philips I2C compatible)
– Programmable Watchdog Timer with Separate On-chip Oscillator
– On-chip Analog Comparator
– Interrupt and Wake-up on Pin Change
• Special Microcontroller Features
– Power-on Reset and Programmable Brown-out Detection
– Internal Calibrated Oscillator
– External and Internal Interrupt Sources
– Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby, and Extended Standby
• I/O and Packages
– 23 Programmable I/O Lines
– 28-pin PDIP, 32-lead TQFP, 28-pad QFN/MLF and 32-pad QFN/MLF
• Operating Voltage:
– 1.8 - 5.5V for ATmega48PA/88PA/168PA/328P
• Temperature Range:
– -40°C to 85°C
• Speed Grade:
– 0 - 20 MHz @ 1.8 - 5.5V
•Low Power Consumption at 1 MHz, 1.8V, 25°C for ATmega48PA/88PA/168PA/328P:
– Active Mode: 0.2 mA
– Power-down Mode: 0.1 μA
– Power-save Mode: 0.75 μA (Including 32 kHz RTC)
5.4 Power
The ARDUINO UNO can be powered via the usb connection or with an external power supply. The power source is selected automatically.
External (non-usb) power can come either from an ac-to-dc adapter (wall-wart) or battery. The adapter can be connected by plugging a 2.1mm center-positive plug into the board's power jack. Leads from a battery can be inserted in the gnd and vin pin headers of the power connector.
The board can operate on an external supply of 6 to 20 volts. If supplied with less than 7v, however, the 5v pin may supply less than five volts and the board may be unstable. If using more than 12v, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts.
The power pins are as follows: * VIN. The input voltage to the Arduino board when it's using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin. * 5V.This pin outputs a regulated 5V from the regulator on the board. The board can be supplied with power either from the DC power jack (7 - 12V), the USB connector (5V), or the VIN pin of the board (7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and can damage your board. We don't advise it. * 3V. A 3.3 volt supply generated by the on-board regulator. Maximum current draw is 50 mA. * GND. Ground pins.
5.5 Memory
The ATmega328 has 32 KB (with 0.5 KB used for the bootloader). It also has 2 KB of SRAM and 1 KB of EEPROM (which can be read and written with the EEPROM library).
5.6 Input and Output
Each of the 14 digital pins on the Uno can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have specialized functions: * Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the corresponding pins of the ATmega8U2 USB-to-TTL Serial chip. * External Interrupts: 2 and 3. These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details. * PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output with the analogWrite() function. * SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication using the SPI library. * LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off.
The Uno has 6 analog inputs, labeled A0 through A5, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and the analogReference() function. Additionally, some pins have specialized functionality: * TWI: A4 or SDA pin and A5 or SCL pin. Support TWI communication using the Wire library.
There are a couple of other pins on the board: * AREF. Reference voltage for the analog inputs. Used with analogReference(). * Reset. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.

CHAPTER 6 FUTURE SCOPE
The wireless control of DC motor has a very wide scope. As the wires are removed, it can be used to operate the motor at longer distances, also it looks better. This system is more reliable as problems due to braking and short circuit of fault is eliminated up to a great extent. The effect of noise is removed as control signal is transmitted in form of RF Waves which are not affected by obstructions and noise. Because of all these advantages it can be implemented for controlling of multiple motors at remote locations from single remote control. It can be used to control the motor which is installed in locations which are more prone to hazards. This system can be implemented for door actuators, security purpose, robotics, defense applications. It can be extended to control of large motors in future.

REFERENCES
Radio frequency applications by Morris Hamington www.radiotronix.com http://arduino.cc/en/Main/arduinoBoardUno http://arduino.cc/en/Tutorial/HomePage http://www.atmel.com/Images/doc8161.pdf http://www.holtek.com/pdf/consumer/2_12ev120.pdf http://www.farnell.com/datasheets/1525377.pdf http://www.datasheetarchive.com/STT+433-datasheet.html Go wireless magazine