Introduction: Road Following Robot"Tweety BOT"
Tweety Bot is simply an advanced version of a Line Follower Robot. It consists of two major
(1) Hardware ( includes the sensors and driving mechanisms )
(2) Software ( path following and grid solving algorithm )
The Hardware of Tweety bot:
The hardware of the tweety bot plays a vital role in functionality of the robot. It should be capable of
providing accurate information to the “brain” of the tweety bot and should be efficient in executing
the decisions made by it. The hardware includes:
(a) An array of Sensors
(b) Motors for driving the mouse
(c) The Brain of the mouse
(d) Power Supply to the entire system
(for NRW contest i am 24)
Step 1: Sensors
Sensors are used in a tweety bot for the purpose of line (grid) following and to determine the
obstructions (red cubes) in the course. This can either done using Light Dependent Resistors (LDR) or
Infrared Sensors (IR Sensors).
The LDR when connected series in a circuit varies its resistance depending upon the intensity of
visible light available. So when an LDR coupled with a visible light source (usually a LED) shows better
low resistance on a white surface (high amount of reflection) and much higher resistance on a black
surface (less amount of reflection). The LDR and LED couple is mounted such a way that one is
beside another both facing the surface. Any number of sensors can be used to increase the
efficiency but depending upon the processing speed of the brain – “Microcontroller” of my bot.
A minimum of three sensors are required to get accurate results out of the grid.
An IR sensor uses the same principle but uses Infrared LEDs instead of ordinary LEDs. Both IR and
LDRs can be used for line following, but it would be better to use an IR sensor for determining the
Step 2: Motors
Any geared motor can be used to drive a minimouse. But one should be ensure that the motor is not
too fast that the sensors don’t get sufficient time to sense the grid. Direct connection of motor with
the microcontroller is not possible. So for ordinary geared motors a motor driving IC L293D (an H
bridge) must be used. It has got many other functions such as enabling differential drive (mobility in
all direction) and pulse width modulation for controlling the speed of motor.
Step 3: Brain of the "Tweety Bot"
Micro controllers are programmable ICs in which you can store a program in machine code and
execute it. There are many micro controllers but use of either ATmega 16 or ATmega 32 will be
sufficient for solving the minimouse. Besides the have the advantage that they don’t need a special
programmer circuit to write the machine codes in it. ATmega 16 and ATmega 32 are basically same
in pin diagram and function except the fact that ATmega 32 has more programmable memory.
ATmega 16 has 4 ports and each port having eight pins. A port is place where you can give your input
(sensors) and tap outputs (motors) depending upon the way they are defined in the program (code)
you load into the micro controller.
Step 4: Coding of the "Tweety BOT"
Step 5: Mechanism
As shown in the image the bot is having 4 injections with 4 compass attached to it.These comnpass have 4 pencils with attached sensors at the tip of it.
This mechanism is used to provide flexibility in design and control.
Injection provide linear changes and compass provide angular changes.
These modifications is used to judge the turns of the road easily.
Step 6: Test Arena
In order to test my bot an arena is prepared as shown in image.