1. World University of Bangladesh
Presented By:
Toukir Ahmad
WUB/09/18/67/4291
Nazmus Sakib
WUB/09/18/67/4282
Design and Construction of DC Motor Speed
Controller Using Android
Supervised By:
Md. Istianatur Rahman
Sr.Lecturer
Department of EEE

2. Background
Rapid progress in microelectronics and microcontrollers in recent years has made it possible to apply
modern control technology to control efficient and reliable operation of many applications such as the
engine, anti-lock braking system (ABS), cruise, steering, and vehicle traction. Many of these
operations including DC motor and therefore there is a need for implementing effective control
strategies with digital control of these motors. The speed of DC motor is directly proportional to
armature voltage and inversely proportional to field flux and adjustable speed drives can be operated
over a wide range by controlling armature or field excitation. Development of various solid state
switching devices such as diode, transistor and thyristor along with various analog/digital chips used
in firing/controlling circuits, have made dc drives more handy for control in numerous areas of
applications. For DC motor speed control, closed-loop PWM technique is widely used and well known
. In this technique, the regulation of motor’s speed is realized by changing the voltage of motor which
is adjusted by the duty ratio of PWM. In order to improve the performance of motor’s speed
regulation and to reduce the steady-state error of the rotational speed of motor, a high- performance
microcontroller can be used.In this work, an arduino microcontroller is used for implementation.
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3. Executive Summary
This work presents a simple speed control application for a DC motor . The purpose
of this application is to maintain the desired speed on a generator operating on the same
axis to the motor .Bluetooth is an emerging technology that is making our world smarter.
The idea of connected world cannot be imagined without IoT. An Bluetooth based Motor
Control is one such example. In Bluetooth enabled Motor control environment various
things such as Machines, all are connected to the Internet and allowing user to monitor and
control things regardless of time and location constraint. In our country, most of time
electrical loads are left ON even when they are not needed. To reduce wastage of electrical
energy, it is important to use electricity as per the requirement. In this thesis book, an IoT
based prototype of a Motor Controller is designed and implemented. The proposed
prototype Motor Controller along with its Android App and Node MCU and Arduino
module as its main controller is successfully implemented and the results of the
implementation are presented.
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4.  To design and implement a Bluetooth based control unit to wirelessly control a
Motor using PWM technique.
Objectives
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5. Methodology
• Creating an idea for Design and Construction of Closed Loop DC
Motor Speed Controller Using PWM. And designing a block diagram &
circuit diagram to know which components need to construct it.
• Collecting the all components and programming for the microcontroller
to controlled the system.
• Setting all components in a PCB board & soldering. Then assembling
the all block in a board and finally run the system & checking.
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6. System Block diagram
Figure: Block Diagram Of Bluetooth Based Motor Speed Control & RPM Checker System.
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7. Schematic Diagram
Figure: Schematic Diagram Of Bluetooth Based Motor Speed Control & RPM Checker System.
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8. Working Principle
The system gives the user the ability to control the speed and the movement direction of
four D.C motors that are represented by a small model car through an Android
application that is developed for mobile devices. The user connects to the model car via
a Bluetooth connection and sends commands for controlling the model car. The
application sends a text message to the HC-05 slave module then the text message is
processed by the Arduino Nano that controls the L298N drivers thus controlling the DC
motors The text message “1” is used for RPM 100 movement, the text message “2” is
used for RPM 500 movement, the text message “3 ” is used for RPM 1000 movement,
the text message “4” is used for RPM 1500 movement and the text message “0” is use to
stop the DC motors.
.
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9. Arduino Uno Microcontroller
• Arduino is an open-source electronics prototyping platform.
• Arduino can sense the environment by receiving input from a variety of sensors
and can affect its surroundings by controlling lights, motors, and other
actuators.
Fig: An Arduino Uno
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10. HC-05 Bluetooth Module
HC-06 Bluetooth Module is a Class 2 slave module that is made for wireless serial communications. If
the module is paired with a primary Bluetooth device (e.g. computer, smartphone, tablet) its transmission
becomes transparent to the user. All the data received by the module via the serial input from the
microcontroller is immediately transmitted and when the module receives data, it is sent via the serial
interface. Interfacing the module with a microcontroller doesn’t need a specific software code because of
the serial interface mention above. The HC-06 Bluetooth module operates at voltage between 3.6V and
6V
.
The HC-06 technical specifications are:
- Bluetooth chip: CSR
- Technology: Bluetooth 2.0 + EDR
- Operating voltage: 3.6V-6V
- UART interface with configurable baud rate
- Supports 8 Mb external flash
- Supports 802.11 protoco
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Fig:HC-06 Bluetooth module

11. .
DC Motor
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A DC motor is any of a class of rotary electrical motors that converts direct current (DC)
electrical energy into mechanical energy. The most common types rely on the forces produced
by magnetic fields. Nearly all types of DC motors have some internal mechanism, either
electromechanical or electronic, to periodically change the direction of current in part of the
motor.DC motors were the first form of motor widely used, as they could be powered from
existing direct-current lighting power distribution systems. A DC motor's speed can be
controlled over a wide range, using either a variable supply voltage or by changing the strength
of current in its field windings. Small DC motors are used in tools, toys, and appliances.
The universal motor can operate on direct current but is a lightweight brushed motor used for
portable power tools and appliances. Larger DC motors are currently used in propulsion of
electric vehicles, elevator and hoists, and in drives for steel rolling mills

12. L293D H-Bridge Motor Driver
 L293D Dual H-Bridge Driver.
 Motor direction can be controlled.
 IN1 and IN2 fed from PWM.
 Max Motor output 36v
 Supply Range 4.5-36V
 Max current output 1.2 A,
Max temperature 70 degrees Fahrenheit.
 Low Power Sleep mode and internal shutdown functions for over temperature
protection.
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13. List Of Components With Price
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Sl.no Particulars Specification Qty. Unit Price (Taka) Total Price
(Taka)
1 Arduino Nano Atmega 328p 1 800 800
2 LCD display 16*2 1 250 250
3 Brashless Motor 1 100 100
4 HC-06 Bluetooth
module
1 350 350
5 IR Sensor 1 350 350
6 L293D Motor Driver
IC
3 150 150
7 Buzzer 1 10 10
8 12 volt step Down
Transformer
1A 1 120 120
9 Diode 1 15 15
10 7805 Voltage
Regulator ic
2 7 14
11 Capacitor 2 10 20
12 Others 500 500
Total 2660/=

14. Resulting RPM, Voltage ,Current graph

15. Advantages
 Direction control from a remote place
 It is easy to operate.
 The system has high sensitivity and not much sensitive to the environmental
changes
 The system is reliable and inexpensive. The control unit can control a BLDC
Motor over a long distance, also the hardware and software components required
in the system implementation are locally and readily available.
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16. Applications
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Motor possess excellent torque speed characteristics and offer a wide
range of speed control, and due to this the demand for motors will be
undiminished.
Robotics
Remote control car.
Quad copter/Drone.
Industrial Uses.
Household Uses.

17. This system accurately controls the speed of the motor using PWM Technique. The system
uses an Arduino Nano & Node MCU to achieve this purpose. We here constantly monitor
the motor speed using an IR sensor. The sensor is used to keep track of the fan motor
rotation and measure its RPM .The sensor is interfaced with the microcontroller and
provides input to the microcontroller. The microcontroller then calculates motor speeds
based on signals provided by the sensor. The microcontroller is also interfaced with an
LCD display to display the status of the system along with motor speed. The project uses
fuzzy logic to increase and decrease PWM supply based on the fan speed monitored to
keep it spinning very close to the desired speed. Thus microcontroller constantly supplies
PWM pulses to keep the motor running around the desired speed as per the PWM
Technique.
Discussion
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18. This paper is an introduction to the world of control systems using Bluetooth technology and
smart mobile devices based on the Android operating system. The Android smartphone
operating system is a suitable environment for developing an efficient and easy to customize
program, which allows the user to control via a Bluetooth connection the created system. The
controlled system uses the Atmega328 microcontroller, this microcontroller was intended for
the realization of various technical solutions in the field of electronics, mechatronics and
automation. Most wireless control systems use RF modules, but the paper demonstrates
thatthe use of Bluetooth technology is a similar or better solution to effectively and securely
control certain systems that use a wireless connection. The L298N module that controls the
D.C motors is easy to implement together with a development board like the one used to
create this system and the D.C motors with a small size / power still present a viable solution
for various practical applications
Conclusion
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19. Future Scope
 In future this system can developed for Industrial purpose.
 In future it will be more developed which is completely online control.
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20. Thank You