Training report on embedded sys_AVR

A

Practical Training Report On

Embedded System Taken at

RaycoreIndia PVT. LTD., Greater NOIDA

Submitted in Partial Fulfilment of

Bachelor of Technology ECE IV Year VII Semester

Galgotias College of Engineering and Technology

Session (2016-2017)

Submitted by:-

Saket Mishra

Roll No.-1309731082

Submitted To:-

Mr. Depaak Gangwar

Department of Electronics & Communication Engineering

Galgotias College of engineering and technology, Greater NOIDA

CONTENTS

Serial

No.

Topic

1. Company Review

2. Training certificate

3. Embedded System

4. Microcontroller (AVR)

5. Architecture of AVR (Atmega 16)

6. Embedded C

7. Interfacing of AVR

8. Modules

9. Project

10. Bibliography

1. Company Overview

RaycoreIndia Research & automation PVT. LTD. is the start-up leader in electronics,

software, services and solutions that help people and businesses realize their full

potential. At RaycoreIndia, we’re motivated and inspired every day by how our

customers use our services to find creative solutions to business problems, develop

breakthrough ideas, and stay connected to what’s most important to them. AN ISO

9001: 2008 certified company

Training And Project development

Embedded | Robotics | Automation

Placement

Software development

Robotics Products

Research

2. Certification

REFF NO: RAYGN/15/1090

Internship Offer Letter

Date: 01/07/2015

SAKET MISHRAROLL NO: 1309731082COLLEGE: GCET / BRANCH: ECE

Dear,

I am pleased to confirm your acceptance of an internship position as software trainee in EMBEDDED SYSTEM. Complete module of ONE year at Greater Noida Branch. Your first day of the training will be 04/07/2015. Your duties and assignments for this position will be those described to you in your orientation with Mr Pradeep.

Please report to the Human Resources Department at 10 a.m. on 04/07/2015 with the appropriate documents and completed forms.

If you have any questions, please feel free to contact Mr Amit. We are very pleased that you have decided to join RaycoreIndia Pvt. Ltd. We look forward to seeing you on 04/17/2015 and offer a very warm welcome.

Sincerely,

Thanking you

HR DEPARTMENT Satish Bhuyan

Raycore India Research & Automation PVT. LTD.

WWW.RAYCOREINDIA.COM : MOB: +91 9643736342: PHONE: 0120 4126369

3. Introduction of Embedded System

Embedded means something that is attached to another thing. An embedded system can be

thought of as a computer hardware system having software embedded in it. An embedded

system can be an independent system or it can be a part of a large system. An embedded

system is a microcontroller or microprocessor based system which is designed to perform a

specific task.

DEFINITION: Embedded System is a combination of Hardware and Software to meet

specific needs in a given time frame.

Embedded systems contain two main elements:

Embedded system hardware: As with any electronic system, an embedded system

requires a hardware platform on which to run. The hardware will be based around a

microprocessor or microcontroller. The embedded system hardware will also contain

other elements including memory, input output (I/O) interfaces as well as the user

interface, and the display.

Embedded system software: The embedded system software is written to perform a

particular function. It is typically written in a high level format and then compiled

down to provide code that can be lodged within a non-volatile memory within the

hardware.

Examples of Embedded System:

Automated transaction machines (ATMS).

Integrated system in aircraft and missile.

Cellular telephones and telephonic switches.

Computer network equipment, including routers timeservers and firewalls

Computer printers, Copiers.

Basic Structure of an Embedded System

Block diagram of a typical embedded system is shown in fig.

CHARACTERISTICS

Embedded systems are application specific & single functioned; the programs are

executed repeatedly.

Efficiency is of paramount importance for embedded systems. They are optimized for

energy, code size, execution time, weight & dimensions, and cost.

Embedded systems are typically designed to meet real time constraints; a real time

system reacts to stimuli from the controlled object/ operator within the time interval

dictated by the environment. For real time systems, right answers arriving too late (or

even too early) are wrong.

Embedded systems often interact (sense, manipulate & communicate) with external

world through sensors and actuators and hence are typically reactive systems; a

reactive system is in continual interaction with the environment and executes at a pace

determined by that environment.

They generally have minimal or no user interface.

4. Microcontroller Embedded Systems

A microcontroller is a functional computer system-on-a-chip. It contains an integrated

processor, memory (a small amount of RAM, program memory, or both), several

peripheral devices, such as timers, analog to digital converters, and serial communication

http://www.engineersgarage.com/microcontroller

http://www.engineersgarage.com/articles/sensors

devices all on one chip resulting in compact and low-power implementations. It is not

expandable as it has no external bus interface.

Microcontrollers provide pin access which allows programs to easily monitor sensors, set

actuators, and transfer data with other devices. Providing specialized instructions

improves performance for embedded systems applications; thus, microcontrollers can be

considered ASIPs to some degree.

AVR

History of AVR:

AVR was developed in the year 1996 by Atmel Corporation. The architecture

of AVR was developed by Alf-Egil Bogen and Vegard Wollan. AVR derives its name

from its developers and stands for Alf-Egil Bogen Vegard Wollan RISC

microcontroller, also known as Advanced Virtual RISC. The AT90S8515 was the first

microcontroller which was based on AVR architecture however the first microcontroller

to hit the commercial market was AT90S1200 in the year 1997.

AVR microcontrollers are available in three categories:

1. Tiny AVR – Less memory, small size, suitable only for simpler applications

2. Mega AVR – These are the most popular ones having good amount of memory

(upto 256 KB), higher number of inbuilt peripherals and suitable for moderate to complex

applications.

3. Xmega AVR – Used commercially for complex applications, which require large

program memory and high speed.

The following table compares the above mentioned AVR series of microcontrollers:

Series Name Pins Flash Memory Special FeatureTiny AVR 6-32 0.5-8 KB Small in size

Mega AVR 28-100 4-256KB Extended peripherals

X mega AVR 44-100 16-384KBDMA , Event System

included

What’s special about AVR?

They are fast: AVR microcontroller executes most of the instructions in single execution

cycle. AVRs are about 4 times faster than PICs, they consume less power and can be operated

in different power saving modes. Let’s do the comparison between the three most commonly

used families of microcontrollers.

CHARACTERISTICS

8051 PIC AVR

SPEED Slow Moderate Fast

MEMORY Small Large Large

ARCHITECTURE CISC RISC RISC

ADC Not Present Inbuilt Inbuilt

TIMERS Inbuilt Inbuilt Inbuilt

PWM Channels Not Present Inbuilt Inbuilt

AVR is an 8-bit microcontroller belonging to the family of Reduced Instruction Set

Computer (RISC). In RISC architecture the instruction set of the computer are not only fewer

in number but also simpler and faster in operation. The other type of categorization is CISC

(Complex Instruction Set Computers).

What is 8-bit? This means that the microcontroller is capable of transmitting and receiving 8-

bit data. The input/output registers available are of 8-bits. The AVR family controllers have

register based architecture which means that both the operands for an operation are stored in

a register and the result of the operation is also stored in a register. Following figure shows a

simple example performing OR operation between two input registers and storing the value

in Output Register.

The CPU takes values from two input registers INPUT-1 and INPUT-2, performs the logical

operation and stores the value into the OUTPUT register. All this happens in 1 execution

cycle.

In our journey with the AVR we will be working on Atmega16 microcontroller, which is a

40-pin IC and belongs to the mega AVR category of AVR family. Some of the features of

Atmega16 are:

o 16KB of Flash memory

o 1KB of SRAM

o 512 Bytes of EEPROM

o Available in 40-Pin DIP

o 8-Channel 10-bit ADC

o Two 8-bit Timers/Counters

o One 16-bit Timer/Counter

o 4 PWM Channels

o In System Programmer (ISP)

http://www.engineersgarage.com/atmega16-avr-microcontroller

o Serial USART

o SPI Interface

o Digital to Analog Comparator.

5. Architecture of AVR

The AVR microcontrollers are based on the advanced RISC architecture and consist of 32 x

8-bit general purpose working registers. Within one single clock cycle, AVR can take inputs

from two general purpose registers and put them to ALU for carrying out the requested

operation, and transfer back the result to an arbitrary register. The ALU can perform

arithmetic as well as logical operations over the inputs from the register or between the

register and a constant. Single register operations like taking a complement can also be

executed in ALU. We can see that AVR does not have any register like accumulator as in

8051 family of microcontrollers; the operations can be performed between any of the

registers and can be stored in either of them.

AVR follows Harvard Architecture format in which the processor is equipped with separate

memories and buses for Program and the Data information. Here while an instruction is being

executed, the next instruction is pre-fetched from the program memory.

Since AVR can perform single cycle execution, it means that AVR can execute 1 million

instructions per second if cycle frequency is 1MHz. The higher is the operating frequency of

the controller, the higher will be its processing speed. We need to optimize the power

consumption with processing speed and hence need to select the operating frequency

accordingly.

There are two flavours for Atmega16 microcontroller:

1. Atmega16:- Operating frequency range is 0 – 16 MHz

2. Atmega16L:- Operating frequency range is 0 – 8 MHz

If we are using a crystal of 8 MHz = 8 x 106 Hertz = 8 Million cycles, then AVR can execute

8 million instructions.

Naming Convention

The AT refers to Atmel the manufacturer, Mega means that the microcontroller belong to

Mega AVR category, 16 signifies the memory of the controller, which is 16KB.

Architecture Diagram: Atmega16

Following points explain the building blocks of Atmega16 architecture:

I/O Ports: Atmega16 has four (PORTA, PORTB, PORTC and PORTD) 8-bit input-output

ports.

Internal Calibrated Oscillator: Atmega16 is equipped with an internal oscillator for driving

its clock. By default Atmega16 is set to operate at internal calibrated oscillator of 1 MHz The

maximum frequency of internal oscillator is 8Mhz. Alternatively, ATmega16 can be operated

using an external crystal oscillator with a maximum frequency of 16MHz.

ADC Interface: Atmega16 is equipped with an 8 channel ADC (Analog to Digital

Converter) with a resolution of 10-bits. ADC reads the analog input for e.g., a sensor input

and converts it into digital information which is understandable by the microcontroller.

Timers/Counters: Atmega16 consists of two 8-bit and one 16-bit timer/counter. Timers are

useful for generating precision actions for e.g., creating time delays between two operations.

Interrupts: Atmega16 consists of 21 interrupt sources out of which four are external. The

remaining are internal interrupts which support the peripherals like USART, ADC, Timers

etc.

USART: Universal Synchronous and Asynchronous Receiver and Transmitter interface

is available for interfacing with external device capable of communicating serially (data

transmission bit by bit).

General Purpose Registers: Atmega16 is equipped with 32 general purpose registers which

are coupled directly with the Arithmetic Logical Unit (ALU) of CPU.

Memory: Atmega16 consist of three different memory sections:

Flash EEPROM: Flash EEPROM or simple flash memory is used to store the

program dumped or burnt by the user on to the microcontroller. It can be easily erased

electrically a single unit. Flash memory is non-volatile i.e., it retains the program even

if the power is cut-off. Atmega16 is available with 16KB of in system programmable

Flash EEPROM.

Byte Addressable EEPROM: This is also a non-volatile memory used to store data

like values of certain variables. Atmega16 has 512 bytes of EEPROM, this memory

http://www.engineersgarage.com/embedded/avr-microcontroller-projects/serial-communication-atmega16-usart

http://www.engineersgarage.com/embedded/avr-microcontroller-projects/external-hardware-interrupts

http://www.engineersgarage.com/embedded/avr-microcontroller-projects/adc-circuit

can be useful for storing the lock code if we are designing an application like

electronic door lock.

SRAM: Static Random Access Memory, this is the volatile memory of

microcontroller i.e., data is lost as soon as power is turned off. Atmega16 is equipped

with 1KB of internal SRAM. A small portion of SRAM is set aside for general

purpose registers used by CPU and some for the peripheral subsystems of the

microcontroller.

ISP: AVR family of controllers have In System Programmable Flash Memory which can

be programmed without removing the IC from the circuit, ISP allows to reprogram the

controller while it is in the application circuit.

SPI: Serial Peripheral Interface, SPI port is used for serial communication between two

devices on a common clock source. The data transmission rate of SPI is more than that of

USART.

TWI: Two Wire Interface (TWI) can be used to set up a network of devices, many devices

can be connected over TWI interface forming a network, the devices can simultaneously

transmit and receive and have their own unique address.

DAC: Atmega16 is also equipped with a Digital to Analog Converter (DAC) interface

which can be used for reverse action performed by ADC. DAC can be used when there is a

need of converting a digital signal to analog signal.

AVR Pin description:

Pin No. Pin name Description Alternate Function

1 (XCK/T0) PB0 I/O PORTB, Pin 0

T0: Timer0 External Counter Input.

XCK : USART External Clock I/O

2 (T1) PB1 I/O PORTB, Pin 1 T1:Timer1 External Counter Input

3 (INT2/AIN0) PB2 I/O PORTB, Pin 2

AIN0: Analog Comparator Positive I/P

INT2: External Interrupt 2 Input

4 (OC0/AIN1) PB3 I/O PORTB, Pin 3

AIN1: Analog Comparator Negative I/P

OC0 : Timer0 Output Compare Match Output

5 (SS) PB4 I/O PORTB, Pin 4 In System Programmer (ISP)

Serial Peripheral Interface (SPI)

6 (MOSI) PB5 I/O PORTB, Pin 5

7 (MISO) PB6 I/O PORTB, Pin 6

8 (SCK) PB7 I/O PORTB, Pin 7

9 RESET Reset Pin, Active Low Reset

10 Vcc Vcc = +5V

11 GND GROUND

12 XTAL2 Output to Inverting Oscillator Amplifier

13 XTAL1 Input to Inverting Oscillator Amplifier

14 (RXD) PD0 I/O PORTD, Pin 0USART Serial Communication Interface

15 (TXD) PD1 I/O PORTD, Pin 1

16 (INT0) PD2 I/O PORTD, Pin 2 External Interrupt INT0

17 (INT1) PD3 I/O PORTD, Pin 3 External Interrupt INT1

18 (OC1B) PD4 I/O PORTD, Pin 4

PWM Channel Outputs

19 (OC1A) PD5 I/O PORTD, Pin 5

20 (ICP) PD6 I/O PORTD, Pin 6 Timer/Counter1 Input Capture Pin

21 PD7 (OC2) I/O PORTD, Pin 7 Timer/Counter2 Output Compare Match Output

22 PC0 (SCL) I/O PORTC, Pin 0TWI Interface

23 PC1 (SDA) I/O PORTC, Pin 1

24 PC2 (TCK) I/O PORTC, Pin 2

JTAG Interface25 PC3 (TMS) I/O PORTC, Pin 3

26 PC4 (TDO) I/O PORTC, Pin 4

27 PC5 (TDI) I/O PORTC, Pin 5

28 PC6 (TOSC1) I/O PORTC, Pin 6 Timer Oscillator Pin 1

29 PC7 I/O PORTC, Pin 7 Timer Oscillator Pin 2

(TOSC2)

30 AVcc Voltage Supply = Vcc for ADC

31 GND GROUND

32 AREF Analog Reference Pin for ADC

33 PA7 (ADC7) I/O PORTA, Pin 7 ADC Channel 7








6. Embedded C (AVR Programming language)

Embedded c is a subset of c language which is compatible with certain

microcontrollers.

Some features are added using header files like <avr/io.h>, <util/delay.h>.

Scanf and printf are removed as the inputs are scanned from the sensors and outputs

are given to the ports.

Control structures remain the same like if-statement, for loop, do while etc.

STRUCTURE OF A C PROGRAM FOR AN EMBEDDED SYSTEM

//Headers

#include<avr/io.h>//header file for avr I/O

#include<util/delay.h>//header file for delay

//main program

{

int main ()

while (1)

{

Code….

}

return(0);

}

We have four Ports

PORT A

PORT B

PORT C

PORT D

All ports have Read-Modify-Write functionality (all pins are capable of performing dual

functions)

Points to be noted for Programming:

PORT : group of 8 pins, or set of pins used for exchanging data with external world

Width of almost all registers : 8 bits (some 16 bits)

In port related registers, every bit corresponds to one pin of the port.

Bit 0 corresponds to Pin 0 & Bit 0 corresponds to Pin 1... Etc.

Remember direct one to one correspondence between HEX and BINARY numbers.

0xFF = 1111 1111

0xAA = 1010 1010

0x11 = 0001 0001

Input/output Basics:

DDRx: Data Direction (input/output) pins

Configures data direction of the port - Input / Output

DDRx.n = 0 > makes corresponding port pin as input

DDRx.n = 1 > makes corresponding port pin as output

Examples :

1. To make all pins of port A as input pins :

DDRA = 0b00000000;

2. To make all pins of port A as output pins

DDRA = 0b11111111;

3. To make lower nibble of port B as output and higher nibble as input

DDRB = 0b00001111;

PIN Register

Used to read data from port pins, when port is configured as input.

First set DDRx to zero, then use PINx to read the value.

If PINx is read, when port is configured as output, it will give you data that has

been outputted on port.

1. Example :

DDRA = 0x00; //Set PA as input

x = PINA; //Read contents of PA

PORT Register

For data output, when port is configured as output:

Writing to PORTx.n will immediately (in same clock cycle) change state of the

port pins according to given value.

Do not forget to load DDRx with appropriate value for configuring port pins as

output.

Examples :

1. To output 0xFF data on PB

DDRB = 0b11111111; //set all pins of port b as outputs

PORTB = 0xFF; //write data on port

2. To output data in variable x on PA

DDRA = 0xFF; //make port a as output

PORTA = x; //output 8 bit variable on port

For configuring pin as tristate/pullup, when port is configured as input):

When port is configures as input (i.e. DDRx.n=1), then PORTx.n controls the

internal pull-up resistor.

PORTx.n = 1 : Enables pullup for nth bit

PORTx.n = 0 : Disables pullup for nth bit, thus making it tristate

Examples :

1. To make PA as input with pull-ups enabled and read data from PA

DDRA = 0x00; //make port a as input

2. PORTA = 0xFF; //enable all pull-ups

y = PINA; //read data from port a pins

3. To make PB as tri stated input

DDRB = 0x00; //make port b as input

4. PORTB = 0x00; //disable pull-ups and make it tri state

7. Interfacing and sending code from PC to AVR

Steps for coding in AVR Studio:

AVR studio is an Integrated Development Environment (IDE) by ATMEL for developing

applications based on AVR microcontroller.

STEP 1:

http://www.engineersgarage.com/articles/avr-microcontroller

Click on new project.

STEP 2:

1. Click on AVR GCC

2. Write the project name

3. Select your project location.

4. Click on Next>>

STEP 3:

1. Click on AVR Simulator in left block and then select your controller

(e.g.: ATmega16).

2. Click on finish button.

STEP 4:

1. Write the code in main body area.

2. Save the project file.

STEP5:

http://www.engineersgarage.com/atmega16-avr-microcontroller

Go to BUILD -> Compile.

This will compile your code and generate error if there will be any.

STEP 6:

Again go to BUILD and click on Build. This will generate hex file of the code. Use that Hex

file to burn your microcontroller.

USBASP USB Programmer:

The USBasp USB programmer is connected to PC from USB side and to the AVR through

wires from the pin side. The connection is used to send the HEX file from PC to AVR

microcontroller.

The converted HEX file of the code is sent from PC/ system to the microcontroller is done by

a software called, sinaprog.

STEP 1: Click the “Folder” icon in the Hex file section and browse for the Hex file of the

project, which you want to download to the microcontroller and Select the HEX file.

STEP 2: Click the “Program” button in the Flash section to start the download of

code/program (Hex file of project) to the Flash memory of the microcontroller.

STEP 3: If the code/program download succeeds, then “Programming Flash…OK” is

displayed in the Status section band if the download fails, then “Programming failed” is

displayed in the Status section.

8. Modules1. I R sensors:

The principle of operation of an infrared sensor is based on infrared light that is

reflected when hitting an obstacle. An IR receiver (Photo Diode) captures the

reflected light and the voltage are measured based on the amount of light received.

Infrared sensors are used in a wide range of applications proximity detection, robotic

applications for distance and object detection, and colour detection and tracking. The

output of the IR sensor can be digital or analog.

If the output of the analog IR sensor is analog in nature and these analog signals

cannot be processed directly by the ATmega16 microcontroller. So, first this signal

needs to be converted to digital value to be processed by the microcontroller. The

conversion can be done with the help of ADC of the AVR ATmega16

microcontroller. After converting the analog signal to digital, the microcontroller will

display the digital value in the 1×8 LED array.

Pin description:

Pin 1 is the output so we wire this to a visible LED and resistor

Pin 2 is ground

Pin 3 is VCC, connect to 5V

2. Relay:Relays are very interesting and useful electronic component. They are a kind of

switch, like those we use every day in our home and offices to turn on and off

electrical devices like bulbs, TVs, fans etc. The function of relay is to control the

switching of a relatively heavier load which demands high voltages (like 240 V AC

mains) or high current, from a relatively low voltage control signal (like 5v or 12v).

When power flows through the first circuit (1), it activates the electromagnet (brown),

generating a magnetic field (blue) that attracts a contact (red) and activates the second

circuit (2). When the power is switched off, a spring pulls the contact back up to its

original position, switching the second circuit off again.

Relays have the exact working of a switch. A relay is said to switch one or more

poles. Each pole has contacts that can be thrown in mainly three ways. They are

Normally Open Contact (NO) – NO contact is also called a make contact. It closes

the circuit when the relay is activated. It disconnects the circuit when the relay is

inactive.

http://www.explainthatstuff.com/how-springs-work.html

Normally Closed Contact (NC) – NC contact is also known as break contact. This is

opposite to the NO contact. When the relay is activated, the circuit disconnects. When

the relay is deactivated, the circuit connects.

Change-over (CO) / Double-throw (DT) Contacts – This type of contacts are used

to control two types of circuits. They are used to control a NO contact and also a NC

contact with a common terminal. According to their type they are called by the

names break before make and make before break contacts.

3. Transmitter and receiver :An RF Transmitter and Receiver pair is used for wireless communication. The

wireless data transmission is done using 433 MHz Radio Frequency signals. The

circuit is divided into transmitter and receiver sections. The transmitter section

consists of an RF Transmitter, HT12E encoder IC and four push buttons. The receiver

section consists of RF Receiver, HT12D Decoder IC and four LEDs. An extra LED is

connected to VT (Valid Transmission) pin of the decoder IC. This is used to indicate a

successful transmission of data

The RF transmitter transmits this serial data using radio signals. At the receiver side,

the RF receiver receives the serial data.

RF Transmitter

Pin No Function Name

1 Ground (0V) Ground

2 Serial data input pin Data

3 Supply voltage; 5V Vcc

4 Antenna output pin ANT

RF Receiver

Pin No Function Name


2 Serial data output pin Data

3 Linear output pin; not connected NC





8 Antenna input pin ANT

LCD Module:

LCD (Liquid Crystal Display) screen is an electronic display module and find a wide

range of applications. A 16x2 LCD display is very basic module and is very

commonly used in various devices and circuits. A 16x2 LCD means it can display 16

characters per line and there are 2 such lines. In this LCD each character is displayed

in 5x7 pixel matrix. This LCD has two registers, namely, Command and Data. The

command register stores the command instructions given to the LCD. A command is

an instruction given to LCD to do a predefined task like initializing it, clearing its

screen, setting the cursor position, controlling display etc. The data register stores the

data to be displayed on the LCD. The data is the ASCII value of the character to be

displayed on the LCD.

Bluetooth Module:

Bluetooth is a type of wireless communication protocol used to send and receive date

between two devices. It is free to use wireless communication protocol.

The Module has two modes of operation namely,

AT Command Mode:

It is a mode of the module where a set of commands (AT Commands) are used to

setup and configure the module. In this mode, the module can’t be detected by other

Bluetooth Devices. For this mode take Key pin to HIGH. All the Commands are sent

to the module serially as a string.

Connection Mode:

In this mode the device can directly communicate with other devices. We can search

this device on other devices and can connect via entering the passkey.

The connections between HC05 module & microcontroller or other device are simple

as below:

VCC ——> 5.0V

GND ——> GND

TXD ——> RXD

RXD ——> TXD

9. PROJECT

Title: Bluetooth Based Home Automation system using smart phone.

Tools used: AVR microcontroller, AVR studio 4.0, UASasp programmer, Bluetooth HC

-06, Relays, Motors/ Bulb , Android smart phone , Wires.

Theory: We design a relay and HC-06 Bluetooth based Android Mobile controlled

wireless

Home Automation system with AVR ATmega16 microcontroller .We will also

use

the Android Mobile as the input device to control the appliances wirelessly.

The communication between HC-06 Bluetooth Module and Android Mobile takes

place through wireless Bluetooth technology. And the communication between

HC-06 Bluetooth Module and ATmega16 microcontroller takes place through

UART serial communication protocol. The HC-06 Bluetooth Module and Android

Mobile are connected through Bluetooth. User enters the control signal from

Android Mobile through Bluetooth Terminal App and the Android Mobile

transmits the control signal to the HC-06 Bluetooth Module through its bluetooth.

The HC-06 Bluetooth Module receives the control signal and transmits it to the

ATmega16 microcontroller through UART.The ATmega16 microcontroller

receives the control signal and processes it and sends the required control signal to

the Relay Driver. Relay Driver will turn On or Off the home appliances according

the control signal received from the ATmega16 microcontroller. The ATmega16

microcontroller also sends the appliance status to the Android Mobile through

bluetooth.

Circuit Design:

Code on AVR Studio 4.0:

#define F_CPU 8000000UL

#define USART_BAUDRATE 9600

#define BAUD_PRESCALE (((F_CPU / (USART_BAUDRATE * 16UL))) - 1)

#include<avr/io.h>

#include<util/delay.h>

void BlueInit()

{

UCSRB |= (1 << RXEN) | (1 << TXEN); // Enable transmission and reception

UCSRC |= (1 << URSEL) | (1<<USBS) | (1 << UCSZ0) | (1 << UCSZ1); // Use 8-bit character sizes

UBRRL = BAUD_PRESCALE;

UBRRH = (BAUD_PRESCALE >> 8);

}

void BlueWrChar(unsigned char d)

{ while ((UCSRA & (1 << UDRE)) == 0); // wait till UDR is ready

UDR = d; // send data

}

unsigned int BlueRdChar()

{ while ((UCSRA & (1 << RXC)) == 0); // wait until data has been received

return(UDR); // return the byte

}

int main()

{

unsigned char value;

DDRA=0x0F;

_delay_ms(50); // delay of 50 mili seconds

BlueInit(); // initialization of USART

while(1)

{

value=BlueRdChar(); // get data from serial port

BlueWrChar(value);

if (value=='u' || value=='U')

{

PORTA=0b11111110; // Pattren 1 flow

}

else if (value=='l' || value=='L')

{


}

else if (value=='d' || value=='D')

{


}

else if (value=='r' || value=='R')

{


}

else if (value=='a' || value=='A')

{


}

else if (value=='b' || value=='B')

{


}

else if (value=='c' || value=='C')

{


}

else if (value=='e' || value=='E')

{


_delay_ma(500);

PORTA=0b11111101;

_delay_ma(500);

PORTA=0b11111011;

_delay_ma(500);

PORTA=0b11110111;

_delay_ma(500);

}

else if (value=='f' || value=='F')

{


_delay_ma(500);

PORTA=0b11111011;

_delay_ma(500);

PORTA=0b11111101;

_delay_ma(500);

PORTA=0b11111110;

_delay_ma(500);

}

else if (value=='g' || value=='G')

{

PORTA=0b11110101;

_delay_ma(500); // Pattren 10 flow

PORTA=0b11111010;

_delay_ma(500);

}

else if (value=='h' || value=='H')

{

PORTA=0xff; // Stopped

}

}

return 0;

}

10. Bibliography: www.engineersgarage.com http://raycoreindia.com www.ablab.in www.extremeelectronics.co.in

http://www.ablab.in/

http://www.engineersgarage.com/

Training report on embedded sys_AVR

Engineering

Transcript of Training report on embedded sys_AVR