Indian Institute of Technology Hyderabad ROBOTICS LINE FOLLOWER HARI KISHAN TANDEY – ES12B1008 DILIP KONDAPARTHI – ES12B1010 SAI KARTIK – CE12B1015

MODEL

ROBOT  A robot is a mechanical or virtual artificial agent, usually an electro-mechanical machine which performs a variety of tasks that is guided by a computer program or electronic circuitry.  Types- Stationary robot, Mobile robot.  Constitution of robot- locomotive system, power supply, actuators, sensory devices for feedback, control system.  Applications- Manufacturing industry, medical science, robots in space, national defense, transportation, agriculture etc…

WHY ROBOTICS ?  Robotics inspires to make connections across several disciplines rather than learning topics in isolation as it combines mechanical, electronic, electrical and programming skills.  It gives visual grasp of math and science  It builds logical thinking  It brings out innovation and creativity  It enhances problem solving skills.  As technology becomes increasingly important in today's world, it is invaluable to not only learn how to use technology, but also to understand how to create it.

ATMEGA8  It is a low power CMOS(Complementary Metal Oxide Semiconductor) 8 bit microcontroller based on the AVR architecture.  Microcontroller consists of a Microprocessor which is interfaced to RAM and Flash memory.  Features: It has 8 KB of flash memory 512 bytes of EEPROM 1 KB of SRAM 23 general purpose I/O lines 32 general purpose working registers

PROGRAMMING  Program is written in C language.  Code is written to give instructions to computer to perform a particular task in a particular condition.  Code is compiled to generate machine file.  Computer only understand this machine file which is in the language of 0 & 1.  Now this file is been feed in the memory of the microcontroller.

PORT  PORT is usually a collection of 8 pins.  Input Output functions are set by Three Registers for each PORT.  DDRX ----> Sets whether a pin is Input or Output of PORTX.  PORTX ---> Sets the Output Value of PORTX.  PINX -----> Reads the Value of PORTX.  PORTB - Digital - Output  PORTC - Analog + Digital - Input  PORTD - Digital - Output

MOTOR  Two motors have been used to rotate the two wheels clockwise or anticlockwise. This provides motion to the robot.  Motors are arranged in a fashion called H-Bridge.  H-Bridge-It is an electronic circuit which enables a voltage to be applied across a load in either direction.  It allows a circuit full control over a standard electric DC motor. That is, with an H-bridge, a microcontroller, logic chip, or remote control can electronically command the motor to go forward, reverse, brake, and coast.

MOTOR  To power the motor, two switches are turned on that are diagonally opposed in the H-Bridge.  The combination of switches that are on, decide the motion of robot whether it will go forward, backward or take turn.  IR Analog Sensor:- Transmitter- An infrared emitting diode. Receiver- A phototransistor.

WORKING MODEL  The working model of a line follower consists of two motors, one ATmega8 circuit board, two wheels, two IR sensors, LEDs, wires and power supply.  The IR sensors get the input and according to the program the LEDs glow depending on the input. The two motors rotate together in one direction to go forward or backward. For taking a right turn, the motor at right side stops and left side one continues to rotate. This rotation depends on the program which gives instructions to the motor depending on the input that sensor gives.  IR sensors provide the input, motors give the output and the wheels make the robot to follow a line.

WORKING MODEL  Follower robot is a mobile machine that can follow a path. The path can be a visible black line on a white surface.  The IR sensors receive an analog signal that depends on the intensity of light reflected by the black line of emitted beam by the LEDs.  These signals are sent to the ADC comparator which creates digital signals that are sent to Microcontroller.  The microcontroller gives instructions to motor to perform work..

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