The project is designed to control the speed of a DC motor using an ARM series processor. The speed of DC motor is directly proportional to the voltage applied across its terminals. Hence, if voltage across motor terminal is varied, then speed can also be varied. 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). The project uses input button interfaced to the processor, which are used to control the speed of motor. PWM (Pulse Width Modulation) is generated at the output by the microcontroller as per the program. The program is written in Embedded C. The average voltage given or the average current flowing through the motor will change depending on the duty cycle (ON and OFF time of the pulses), so the speed of the motor will change. A motor driver IC is interfaced to the STM32 board for receiving PWM signals and delivering desired output for speed control of a small DC motor. Further the project can be enhanced by using power electronic devices such as IGBTs to achieve speed control higher capacity industrial motors.

1. MANTHAN-15 ISSN: 2321-8134
http: // www.ijfeat.org (C) International Journal For Engineering Applications and Technology
IJFEAT
INTERNATIONAL JOURNAL FOR ENGINEERING APPLICATIONS AND
TECHNOLOGY
Arm Processor Based Speed Control Of BLDC Motor
Gopal Moti1
, Uday Wankar2
, Surendra Butale3
, Vilas Dorle4
, Kunal Patil5
1
Student, EE,GCOE Chandrapur, Maharashtra, India, motigopal3@gmail.com
2
Student, EE,GCOE Chandrapur, Maharashtra, India, udaywankar@gmail.com
3
Student, EE,GCOE Chandrapur, Maharashtra, India, surendrabutale17@gmail.com
4
Student EE,GCOE Chandrapur, Maharashtra, India, vilasdorle3@gmail.com
5
Student, EE,GCOE Chandrapur, Maharashtra, India, kunalrajendrapatil@gmail.com
Abstract
The project is designed to control the speed of a DC motor using an ARM series processor. The speed of DC motor is directly
proportional to the voltage applied across its terminals. Hence, if voltage across motor terminal is varied, then speed can also be
varied. 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). The project uses input button interfaced to the processor, which are used to control the speed of
motor. PWM (Pulse Width Modulation) is generated at the output by the microcontroller as per the program. The program is written in
Embedded C. The average voltage given or the average current flowing through the motor will change depending on the duty cycle
(ON and OFF time of the pulses), so the speed of the motor will change. A motor driver IC is interfaced to the STM32 board for
receiving PWM signals and delivering desired output for speed control of a small DC motor. Further the project can be enhanced by
using power electronic devices such as IGBTs to achieve speed control higher capacity industrial motors.
Index Terms: ARM, LPC2148, Motor controller, BLDC,PWM etc.
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INTRODUCTION
An ARM processor is one of a family of CPUs based on the
RISC (reduced instruction set computer) architecture
developed by Advanced RISC Machines (ARM). ARM makes
32-bit and 64-bit RISC multi-core processors.
RISC processors are designed to perform a smaller number of
types of computer instructions so that they can operate at a
higher speed, performing more millions of instructions per
second (MIPS). By stripping out unneeded instructions and
optimizing pathways, RISC processors provide outstanding
performance at a fraction of the power demand of CISC
(complex instruction set computing) devices.
The ARM microprocessor generates Pulse Width Modulation.
This signal supplied to dc motor terminal to controlled
different speed of bldc motor. The motor is communicate
through PC through UART. Different values are enter by user
for controlling purpose.
1. PROJECT DESCRIPTION
Our project is a speed control of BLDC motor controlled by
LPC 2148 ARM processor by using Pulse Width Modulation
(PWM) technique. PWM pulses are generated by ARM
processor which are then fed to optocoupler. Optocoupler then
control power given to the BLDC motor. With the ON and
OFF period of pulses, the Speed of BLDC motor is controlled.
The speed of BLDC motor is changed using computer by
HyperTerminal technique in Windows XP.

2. MANTHAN-15 ISSN: 2321-8134
http: // www.ijfeat.org (C) International Journal For Engineering Applications and Technology
Fig-1: Block diagram
2. IMPLEMENTATION
2.1 PWM
Pulse-width modulation (PWM), or pulse-duration modulation
(PDM), is a modulation technique that controls the width of
the pulse, formally the pulse duration, based on modulator
signal information. Although this modulation technique can be
used to encode information for transmission, its main use is to
allow the control of the power supplied to electrical devices,
especially to inertial loads such as motors.
The average value of voltage (and current) fed to the load is
controlled by turning the switch between supply and load on
and off at a fast pace. The longer the switch is on compared to
the off periods, the higher the power supplied to the load.
The main advantage of PWM is that power loss in the
switching devices is very low. When a switch is off there is
practically no current, and when it is on and power is being
transferred to the load, there is almost no voltage drop across
the switch. Power loss, being the product of voltage and
current, is thus in both cases close to zero. PWM also works
well with digital controls, which, because of their on/off
nature, can easily set the needed duty cycle.PWM has also
been used in certain communication systems where its duty
cycle has been used to convey information over a
communications channel.
Fig-2.1: PWM signals of varying duty
cycles
Pulse Width Modulated (PWM) power electronic techniques
represent a large and increasing proportion of modern power
electronics. Like any form of power conversion, PWM drives
or associated loads should be designed and tested to meet
specific performance and efficiency criteria but given the
complexity of waveforms associated with PWM applications,
accurate measurement is not a simple task.
2.2 LPC 2148
The LPC2131/2132/2138 microcontrollers are based on a
32/16 bit ARM7TDMI-S™ CPU with real-time emulation and
embedded trace support, that combines the microcontroller
with 32 kB, 64 kB and 512 kB of embedded high speed Flash
memory. A 128- bit wide memory interface and a unique
accelerator architecture enable 32-bit code execution at
maximum clock rate. For critical code size applications, the
alternative 16-bit Thumb® Mode reduces code by more than
30 % with minimal performance penalty. Due to their tiny size
and low power consumption, these microcontrollers are ideal
for applications where miniaturization is a key requirement,
such as access control and point-of-sale. With a wide range of
serial communications interfaces and on-chip SRAM options
of 8/16/32 kB, they are very well suited for communication
gateways and protocol converters, soft modems, voice
recognition and low end imaging, providing both large buffer
size and high processing power. Various 32-bit timers, single
or dual 10-bit 8 channel ADC(s), 10-bit DAC, PWM channels
and 47 GPIO lines with up to nine edge or level sensitive
external interrupt pins make these microcontrollers
particularly suitable for industrial control and medical
systems.

3. MANTHAN-15 ISSN: 2321-8134
http: // www.ijfeat.org (C) International Journal For Engineering Applications and Technology
2.2.1 Features
• 16/32-bit ARM7TDMI-S microcontroller in a tiny LQFP64
package.
• 8/16/32 kB of on-chip static RAM and 32/64/512 kB of on-
chip Flash program memory. 128 bit wide
interface/accelerator enables high speed 60 MHz operation.
• In-System/In-Application Programming (ISP/IAP) via on-
chip boot-loader software. Single Flash sector or full chip
erase in 400 ms and programming of 256 bytes in 1 ms.
• EmbeddedICE® RT and Embedded Trace interfaces offer
real-time debugging with the on-chip RealMonitor™ software
and high speed tracing of instruction execution.
• One (LPC2131/2132) or two (LPC2138) 8 channel 10-bit
A/D converters provide a total of up to 16 analog inputs, with
conversion times as low as 2.44 s per channel.
• Single 10-bit D/A converter provides variable analog output.
(LPC2132/2138 only)
• Two 32-bit timers/counters (with four capture and four
compare channels each), PWM unit (six outputs) and
watchdog.
• Real-time clock equipped with independent power and clock
supply permitting extremely low power consumption in power
save modes.
• Multiple serial interfaces including two UARTs (16C550),
two Fast I2C (400 kbit/s), SPI™ and SSP with buffering and
variable data length capabilities.
• Vectored interrupt controller with configurable priorities and
vector addresses.
• Up to 47 of 5 V tolerant general purpose I/O pins in tiny
LQFP64 package.
• Up to nine edge or level sensitive external interrupt pins
available.
• 60 MHz maximum CPU clock available from programmable
on-chip Phase-Locked Loop (PLL) with settling time of 100
microseconds.
• On-chip crystal oscillator with an operating range of 1 MHz
to 30 MHz.
• Power saving modes include Idle and Power-down.
• Individual enable/disable of peripheral functions as well as
peripheral clock scaling down for additional power
optimization.
• Processor wake-up from Power-down mode via external
interrupt.
• Single power supply chip with Power-On Reset (POR) and
Brown-Out Detection (BOD) circuits:
- CPU operating voltage range of 3.0 V to 3.6 V (3.3 V 10 %)
with 5 V tolerant I/O pads.
2.3 Optocoupler
In electronics, an opto-isolator, also called an optocoupler,
photocoupler, or optical isolator, is a component that transfers
electrical signals between two isolated circuits by using light.
Opto-isolators prevent high voltages from affecting the system
receiving the signal. Commercially available opto-isolators
withstand input-to-output voltages up to 10 Kvand voltage
transients with speeds up to 10 kV/μs.
A common type of opto-isolator consists of an LED and a
phototransistor in the same opaque package. Other types of
source-sensor combinations include LED-photodiode, LED-
LASCR, and lamp-photoresistor pairs. Usually opto-isolators
transfer digital (on-off) signals, but some techniques allow
them to be used with analog signals.
Fig-2.3: Optocoupler
3. RESULT
We have sussesfully implemented this paper and getting desire
result in the simulation. Different duty cycle generated
through LPC2148 microcontroller and result is analyzed on
CRO which are fed to BLDC motor via optocoupler to
controlled speed.
Fig-3:PWM waveforms of variable duty cycle
4. CONCLUSION
LPC2148 has given 100% accuracy for PWM, the delay angle
has Reduced and controlled desired speed with 100%
accuracy.LPC 2148 Has required less power consumption so
the power is reduced in this paper
REFERENCES
[1]. Arm User Manual, Phillips, August 2005.

4. MANTHAN-15 ISSN: 2321-8134
http: // www.ijfeat.org (C) International Journal For Engineering Applications and Technology
[2]. SteveFurber , ARM SYSTEM-ON-CHIP
ARCHITECTURE, SECOND EDITION, Pearson Education
Limited,2000.
[3]. R. M. Pindoriya, S. Rajendran, P. J. Chauhan “Speed
Control of BLDC Motor using Sinusoidal PWM
Technique”,National Conference On Emerging Trends In
Computer & Electrical Engineering ETCEE-2014, Page 151-
156
[4]. Website: http://en.wikipedia.org/wiki/Duty_cycle.