This document describes how to build a robot that can be controlled via Bluetooth from a mobile phone or PC. An HC-05 Bluetooth module connects to a microcontroller on the robot to receive commands from a Bluetooth-enabled device. The microcontroller then uses a motor driver IC to control the robot's motors to move forward, reverse, or turn based on the received commands.

1. Using HC-05 Bluetooth Module

2.  Aim of the project is to design a robot which
can be controlled by Bluetooth of your mobile
phone or PC.
 An application program running in PC or
android phone is used to send commands that
are received by Bluetooth module attached
with the robot.

3.  Microcontroller (ATMega8) development
board
 PC or Mobile with customizable Bluetooth
module
 HC-05 Bluetooth module
 DC motor
 Motor driver IC (L293D)
 Wheels
 Power adopter

5.  It is required to supply sufficient
current to motors as microcontrollers
can’t supply that much current.
 It is a dual H-Bridge motor
means it can drive two DC
motors simultaneously in both
clockwise and anticlockwise
direction.
 Its input terminals are controlled
by the microcontroller.
It also includes the protection
circuit against back EMF.

6.  This module is capable of
communicating with PC,
mobile phone or any other
Bluetooth enabled device.
 It is interfaced with the
microcontroller over the
serial UART port of micro-controller.

8.  For this firstly the application program is
developed or a readymade program is made
available to run on the PC or the mobile phone.
 The application program send the commands
in form of ASCII characters which are received
by HC-05 Bluetooth module and passed to
microcontroller through UART port of
microcontroller.

9.  The microcontroller is programmed to take
desired actions according to the command
(ASCII character) received to move forward,
reverse or to take a turn.
 The microcontroller sends logic 1 or 0 at the
specified pin to control motors of robot which
are attached using motor driver IC (L293D).