WIRELESS DC MOTOR SPEED AND DIRECTION CONTROL USING RF COMMUNICATION Project Title WIRELESS DC MOTOR SPEED AND DIRECTION CONTROL USING RF COMMUNICATION Under the Guidance of Submitted by

ABSTRACT The main scope of project is to control the DC motor remotely using primarily the RF mode. The remote control besides being Omni directional has the advantage of adequate range (up to 200 meters with proper antenna). However, the microcontroller being used for the project has latched outputs and as such one does not have to keep the buttons on remote control pressed for more than a few milliseconds, this helps prolonging the battery life for remote.  This project uses the above principle to control the speed of the motor by varying the duty cycle of the pulse applied to it (popularly known as PWM control).

PROJECT BLOCK DIAGRAM Transmitter section

Receiver Section

MICROCONTROLLER (AT89S52/AT89C51) RF Transmitter and RF Receiver HARDWARE REQUIREMENTS POWER SUPPLY BLOCK MICROCONTROLLER (AT89S52/AT89C51) RF Transmitter and RF Receiver HT12E/HT12D L293D DC MOTOR PUSH BUTTONS BC547 LED 1N4007 RESISTOR CAPACITOR

POWER SUPPLY Bridge rectifier 5v Regulator 230 V AC 50 Hz 5V DC Filter(470µf) 12V step down transformer

It is a smaller computer Has on-chip RAM, ROM, I/O ports... MICROCONTROLLER It is a smaller computer Has on-chip RAM, ROM, I/O ports... RAM ROM I/O Port Timer Serial COM Port Microcontroller CPU A single chip

INTERNAL STRUCTURE OF A MICRO CONTROLLER-AT89S52/51 CPU On-chip RAM On-chip ROM for program code 4 I/O Ports Timer 0 Serial Port OSC Interrupt Control External interrupts Timer 1 Timer/Counter Bus Control TxD RxD P0 P1 P2 P3 Address/Data Counter Inputs

Features of AT89S51/52 Compatible with MCS®-51 Products 8K Bytes of In-System Programmable (ISP) Flash Memory Endurance: 10,000 Write/Erase Cycles 4.0V to 5.5V Operating Range Fully Static Operation: 0 Hz to 33 MHz 256 x 8-bit Internal RAM 32 Programmable I/O Lines Three 16-bit Timer/Counters Eight Interrupt Sources Full Duplex UART Serial Channel Interrupt Recovery from Power-down Mode Watchdog Timer Dual Data Pointer

Pin Description

RF Transmitter and Receiver RF modules are normally divided into three groups, RF transmitter module, RF receiver module and RF transceiver module 433MHz ASK transmitter and receiver is used for the remote control. Fig : RF Transmitter

Features of RF Range in open space(Standard Conditions) : 100 Meters RX Receiver Frequency : 433 MHz RX Typical Sensitivity : 105 Dbm RX Supply Current : 3.5 mA RX IF Frequency : 1MHz Low Power Consumption Easy For Application RX Operating Voltage : 5V TX Frequency Range : 433.92 MHz TX Supply Voltage : 3V ~ 6V TX Out Put Power : 4 ~ 12 Dbm Fig RF Receiver

HT 12 ENCODER Operating voltage is 2.4V~12V for the HT12E. Features Operating voltage is 2.4V~12V for the HT12E. Low power and high noise immunity CMOS technology Low standby current: 0.1_A (typ.) at VDD=5V HT12A with a 38kHz carrier for infrared transmission medium Minimum transmission words are Four words for the HT12E Built-in oscillator needs only 5% resistor Data code has positive polarity Minimal external components HT12A/E: 18-pin DIP/20-pin SOP package

HT12 DECODER Features Operating voltage: 2.4V~12V. Low power and high noise immunity CMOS technology. Low standby current. Capable of decoding 12 bits of information. Binary address setting. Address/Data number combination for HT12D: 8 address bits and 4 data bits. Valid transmission indicator Minimal external components 18-pin DIP, 20-pin SOP package

MOTOR DRIVER (L293D) Wide supply-voltage range: 4.5V to 36V Features: Wide supply-voltage range: 4.5V to 36V Separate input- logic supply Internal ESD protection Thermal shutdown High-Noise-Immunity input Functional Replacements for SGS L293 and SGS L293D Output current 1A per channel (600 mA for L293D) Peak output current 2 A per channel (1.2 A for L293D) Output clamp diodes for Inductive Transient suppression(L293D)

DESCRIPTION L293D is a dual H-bridge motor driver integrated circuit (IC). In its common mode of operation, two DC motors can be driven simultaneously, both in forward and reverse direction. The motor operations of two motors can be controlled by input logic at pins 2 & 7 and 10 & 15. Input logic 00 or 11 will stop the corresponding motor. Logic 01 and 10 will rotate it in clockwise and anticlockwise directions, respectively. Enable pins 1 and 9 (corresponding to the two motors) must be high for motors to start operating. When an enable input is high, the associated driver gets enabled

DC- MOTOR A DC motor is an electric motor that runs on direct current (DC) electricity. In any electric motor, operation is based on simple electromagnetism. A simple 2-pole DC electric motor (here red represents a magnet or winding with a "North" polarization, while green represents a magnet or winding with a "South" polarization). Every DC motor has six basic parts -- axle, rotor (a.k.a., armature), stator, commutator, field magnet(s), and brushes.

BC547 (NPN –Transistor) The BC547 transistor is an NPN Epitaxial Silicon Transistor. It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors. The ratio of two currents (Ic/Ib) is called the DC Current Gain of the device and is given the symbol of hfe or nowadays Beta, (β).

The current gain from the emitter to the collector terminal, Ic/Ie, is called Alpha, (α), and is a function of the transistor itself

WORKING OF PROJECT The DC motor can be remotely controlled by one transmitting unit and a receiving unit using motors for its moment. Push buttons are arranged and fed to MC which in turn help the DC motor to move in a direction. HT12E Encoder which convert’s 4 bit data to serial output fed to the RF transmitter, the same to be received by the RF receiver module the output of which is fed to HT12D the serial decoder IC, the output of which is fed to MC The data so received at the receiver end operates the motor through motor driver IC L293D as required being interfaced from the Microcontroller  

Software Requirements Keil an ARM Company makes C compilers, macro assemblers, real-time kernels, debuggers, simulators, integrated environments, evaluation boards, and emulators for ARM7/ARM9/Cortex-M3, XC16x/C16x/ST10, 251, and 8051 MCU families. Compilers are programs used to convert a High Level Language to object code. Desktop compilers produce an output object code for the underlying microprocessor, but not for other microprocessors.

i.e the programs written in one of the HLL like ‘C’ will compile the code to run on the system for a particular processor like x86 (underlying microprocessor in the computer). For example compilers for Dos platform is different from the Compilers for Unix platform  So if one wants to define a compiler then compiler is a program that translates source code into object code.

BIBILOGRAPHY “The 8051 Microcontroller and Embedded systems” by Muhammad Ali Mazidi and Janice Gillispie Mazidi , Pearson Education. ATMEL 89S52 Data Sheets. www.atmel.com www.beyondlogic.org www.wikipedia.org www.howstuffworks.com www.alldatasheets.com

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