PC Based Industrial Automation With AVR Atmega 16 - Project Report

A Project report on PC Based Industrial Automation by ROBO INDIA

R O B O I N D I A | w w w . r o b o i n d i a . c o m

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PROJECT REPORT ON PC Based Industrial automation and electric machine

and device control.



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Chapter 1 Introduction

Automation or automatic control is the use of various control systems for operating

equipment such as machinery, processes in factories, boilers and heat treating ovens,

switching in telephone networks, steering and stabilization of ships, aircraft and other

applications with minimal or reduced human intervention. Some processes have been

completely automated.

The biggest benefit of automation is that it saves labour, however, it is also used to save

energy and materials and to improve quality, accuracy and precision.

The term automation, inspired by the earlier word automatic (coming from automaton),

was not widely used before 1947, when General Motors established the automation

department. It was during this time that industry was rapidly adopting feedback

controllers, which were introduced in the 1930s.



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Automation has been achieved by various means including mechanical, hydraulic,

pneumatic, electrical, electronic and computers, usually in combination. Complicated

systems, such as modern factories, airplanes and ships typically use all these combined

techniques.

1.1 Types of automation

Two common types of automation are feedback control, which is usually continuous and

involves taking measurements using a sensor and making calculated adjustments to

keep the measured variable within a set range, and sequence control, in which a

programmed sequence of discrete operations is performed, often based on system logic.

Cruise control is an example of the former while an elevator or an automated teller

machine (ATM) is an example of the latter.

The theoretical basis of feedback control is control theory, which also covers

servomechanisms, which are often part of an automated system. Feedback control is

called "closed loop" while non-feedback control is called "open loop."

1.2 Feedback control

Feedback control is accomplished with a controller. To function properly, a controller

must provide correction in a manner that maintains stability. Maintaining stability is a

principal objective of control theory.

As an example of feedback control, consider a steam coil air heater in which a

temperature sensor measures the temperature of the heated air, which is the measured

variable. This signal is constantly "fed back" to the controller, which compares it to the

desired setting (set point). The controller calculates the difference (error), then

calculates a correction and sends the correction signal to adjust the air pressure to a

diaphragm that moves a positioner on the steam valve, opening or closing it by the

calculated amount. All the elements constituting the measurement and control of a

single variable are called a control loop.

The complexities of this are that the quantities involved are all of different physical

types; the temperature sensor signal may be electrical or pressure from an enclosed

fluid, the controller may employ pneumatic, hydraulic, mechanical or electronic



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techniques to sense the error and send a signal to adjust the air pressure that moves the

valve.

The first controllers used analog methods to perform their calculations. Analog methods

were also used in solving differential equations of control theory. The electronic analog

computer was developed to solve control type problems and electronic analog

controllers were also developed. Analog computers were displaced by digital computers

when they became widely available.

Common applications of feedback control are control of temperature, pressure, flow,

and speed.

1.3 Sequential control and logical sequence control

Sequential control may be either to a fixed sequence or to a logical one that will perform

different actions depending on various system states. An example of an adjustable but

otherwise fixed sequence is a timer on a lawn sprinkler. An elevator is an example that

uses logic based on the system states to perform certain actions in response to operator

input.

A development of sequential control was relay logic, by which electrical relays engage

electrical contacts which either start or interrupt power to a device. Relays were first

used in telegraph networks before being developed for controlling other devices, such

as when starting and stopping industrial-sized electric motors or opening and closing

solenoid valves. Using relays for control purposes allowed event-driven control, where

actions could be triggered out of sequence, in response to external events. These were

more flexible in their response than the rigid single-sequence cam timers. More

complicated examples involved maintaining safe sequences for devices such as swing

bridge controls, where a lock bolt needed to be disengaged before the bridge could be

moved, and the lock bolt could not be released until the safety gates had already been

closed.

The total number of relays, cam timers and drum sequencers can number into the

hundreds or even thousands in some factories. Early programming techniques and

languages were needed to make such systems manageable, one of the first being ladder

logic, where diagrams of the interconnected relays resembled the rungs of a ladder.



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Special computers called programmable logic controllers were later designed to replace

these collections of hardware with a single, more easily re-programmed unit.

In a typical hard wired motor start and stop circuit (called a control circuit) a motor is

started by pushing a "Start" or "Run" button that activates a pair of electrical relays. The

"lock-in" relay locks in contacts that keep the control circuit energized when the push

button is released. (The start button is a normally open contact and the stop button is

normally closed contact.) Another relay energizes a switch that powers the device that

throws the motor starter switch (three sets of contacts for three phase industrial

power) in the main power circuit. (Note: Large motors use high voltage and experience

high in-rush current, making speed important in making and breaking contact. This can

be dangerous for personnel and property with manual switches.) All contacts are held

engaged by their respective electromagnets until a "stop" or "off" button is pressed,

which de-energizes the lock in relay. See diagram: Motor Starters Hand-Off-Auto With

Start-Stop (Note: The above description is the "Auto" position case in this diagram).

Commonly interlocks are added to a control circuit. Suppose that the motor in the

example is powering machinery that has a critical need for lubrication. In this case an

interlock could be added to insure that the oil pump is running before the motor starts.

Timers, limit switches and electric eyes are other common elements in control circuits.

Solenoid valves are widely used on compressed air or hydraulic fluid for powering

actuators on mechanical components. While motors are used to supply continuous

rotary motion, actuators are typically a better choice for intermittently creating a

limited range of movement for a mechanical component, such as moving various

mechanical arms, opening or closing valves, raising heavy press rolls, applying pressure

to presses.

1.4 Computer control

Computers can perform both sequential control and feedback control, and typically a

single computer will do both in an industrial application. Programmable logic

controllers (PLCs) are a type of special purpose microprocessor that replaced many

hardware components such as timers and drum sequencers used in relay logic. General

purpose process control computers have increasingly replaced standalone controllers,



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with a single computer able to perform the operations of hundreds of controllers.

Process control computers can process data from a network of PLCs, instruments and

controllers in order to implement typical (such as PID) control of many individual

variables or, in some cases, to implement complex control algorithms using multiple

inputs and mathematical manipulations. They can also analyse data and create real time

graphical displays for operators and run reports for engineers and management.

Control of an automated teller machine (ATM) is an example of an interactive process in

which a computer will perform a logic derived response to a user selection based on

information retrieved from a networked database. The ATM process has a lot of

similarities to other online transaction processes. The different logical responses are

called scenarios. Such processes are typically designed with the aid of use cases and

flowcharts, which guide the writing of the software code.

1.5 Industrial automation

Industrial automation deals primarily with the automation of manufacturing, quality

control and material handling processes. General purpose controllers for industrial

processes include Programmable logic controllers and computers. One trend is

increased use of Machine vision to provide automatic inspection and robot guidance

functions, another is a continuing increase in the use of robots.

Energy efficiency in industrial processes has become a higher priority. Semiconductor

companies like Infineon Technologies are offering 8-bit micro-controller applications

for example found in motor controls, general purpose pumps, fans, and ebikes to reduce

energy consumption and thus increase efficiency.

1.6 Project Specifications Our industrial automation project is having following features and specification.

1. Number of devices to be controlled: 4

2. Current rating : 10A

3. Voltage : 220V

4. PC based control

5. Hardware interface : USB

6. Control Software : computer interface(GUI)



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7. The project is very user friendly because of the computer interface developed by

us, even layman could operate it.

8. The GUI is platform free and doesn’t require any tool like MATLAB. A single

setup file that can be executed on any both windows operating system i.e. 32/64

bits.

9. We have developed MATLAB based GUI as well.

10. The controlling hardware is using USB that makes it ultra-portable. Unlike to the

old systems of serial ports.



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Chapter 2

Objective

The main objective of our project is to automate industrial devices. We have added 4

relays in our project. These relays are electromechanical switches and can handle

electrical device of AC and DC both. Thus our project is providing automation to a wide

range of industrial devices. Other objectives are to make the project to the possible low

cost. The material used to construct this project is selected after an extensive research

of the market. We have analysed hundreds of options before selecting the components.

We have taken care that low price doesn’t hamper the quality of project.

The optimal utilization of cost makes our project ultra-low cost. The PC based control

requires software that runs on PC. Our software is based on Graphical user interface.



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This makes the project very easy to use. Lab assistants or the operator can use this

software even with proving any sort of training to them.

These are the objectives fulfilled by our project.



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Chapter 3

Methodology The following block diagram explains working of the system, later we shall discuss all of

the components of the diagram.

Fig.2 | Block diagram



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Chapter 4 Programming of hardware controller

This chapter elaborate the programming of hardware controller.

4.1 Introduction to embedded C

Our project is made using embedded programming. The programming language

required for construction of the project is Embedded C. Here in this chapter we will see

the programming of the project and interfacing with the compiler. Before moving ahead

have a look on embedded system.

An embedded system is a computer system with a dedicated function within a larger

mechanical or electrical system, often with real-time computing constraints.It is

embedded as part of a complete device often including hardware and mechanical parts.

By contrast, a general-purpose computer, such as a personal computer (PC), is designed

to be flexible and to meet a wide range of end-user needs. Embedded systems control

many devices in common use today.

Modern embedded systems are often based on microcontrollers (i.e CPUs with

integrated memory and/or peripheral interfaces) but ordinary microprocessors (using



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external chips for memory and peripheral interface circuits) are also still common,

especially in more complex systems. In either case, the processor(s) used may be types

ranging from rather general purpose to very specialised in certain class of

computations, or even custom designed for the application at hand. A common standard

class of dedicated processors is the digital signal processor (DSP).

The key characteristic, however, is being dedicated to handle a particular task. Since the

embedded system is dedicated to specific tasks, design engineers can optimize it to

reduce the size and cost of the product and increase the reliability and performance.

Some embedded systems are mass-produced, benefiting from economies of scale.

Physically, embedded systems range from portable devices such as digital watches and

MP3 players, to large stationary installations like traffic lights, factory controllers, and

largely complex systems like hybrid vehicles, MRI, and avionics. Complexity varies from

low, with a single microcontroller chip, to very high with multiple units, peripherals and

networks mounted inside a large chassis or enclosure.

Embedded systems are commonly found in consumer, cooking, industrial, automotive,

medical, commercial and military applications.

Telecommunications systems employ numerous embedded systems from telephone

switches for the network to cell phones at the end-user. Computer networking uses

dedicated routers and network bridges to route data.

Consumer electronics include personal digital assistants (PDAs), mp3 players, mobile

phones, videogame consoles, digital cameras, DVD players, GPS receivers, and printers.

Household appliances, such as microwave ovens, washing machines and dishwashers,

include embedded systems to provide flexibility, efficiency and features. Advanced

HVAC systems use networked thermostats to more accurately and efficiently control

temperature that can change by time of day and season. Home automation uses wired-

and wireless-networking that can be used to control lights, climate, security,

audio/visual, surveillance, etc., all of which use embedded devices for sensing and

controlling.



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Transportation systems from flight to automobiles increasingly use embedded systems.

New airplanes contain advanced avionics such as inertial guidance systems and GPS

receivers that also have considerable safety requirements. Various electric motors —

brushless DC motors, induction motors and DC motors — use electric/electronic motor

controllers. Automobiles, electric vehicles, and hybrid vehicles increasingly use

embedded systems to maximize efficiency and reduce pollution. Other automotive

safety systems include anti-lock braking system (ABS), Electronic Stability Control

(ESC/ESP), traction control (TCS) and automatic four-wheel drive.

Medical equipment uses embedded systems for vital signs monitoring, electronic

stethoscopes for amplifying sounds, and various medical imaging (PET, SPECT, CT, MRI)

for non-invasive internal inspections. Embedded systems within medical equipment are

often powered by industrial computers. Embedded systems are used in transportation,

fire safety, safety and security, medical applications and life critical systems, as these

systems can be isolated from hacking and thus, be more reliable.[citation needed] For

fire safety, the systems can be designed to have greater ability to handle higher

temperatures and continue to operate. In dealing with security, the embedded systems

can be self-sufficient and be able to deal with cut electrical and communication systems.

A new class of miniature wireless devices called motes are quickly gaining popularity as

the field of wireless sensor networking is increasing. Wireless sensor networking, WSN,

makes use of miniaturization made possible by advanced IC design to couple full

wireless subsystems to sophisticated sensors, enabling people and companies to

measure a myriad of things in the physical world and act on this information through IT

monitoring and control systems. These motes are completely self-contained, and will

typically run off a battery source for years before the batteries need to be changed or

charged.

Embedded Wi-Fi modules provide a simple means of wirelessly enabling any device

which communicates via a serial port.

4.2 The compiler

Atmel® Studio 6 is the integrated development platform (IDP) for developing and

debugging Atmel ARM® Cortex®-M and Atmel AVR® microcontroller (MCU) based



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applications. The Atmel Studio 6 IDP gives you a seamless and easy-to-use environment

to write, build and debug your applications written in C/C++ or assembly code.

Atmel Studio 6 is free of charge and is integrated with the Atmel Software Framework

(ASF)—a large library of free source code with 1,600 ARM and AVR project examples.

ASF strengthens the IDP by providing, in the same environment, access to ready-to-use

code that minimizes much of the low-level design required for projects. Use the IDP for

our wide variety of AVR and ARM Cortex-M processor-based MCUs, including our

broadened portfolio of Atmel SAM3 ARM Cortex-M3 and M4 Flash devices.

With the introduction of Atmel Gallery and Atmel Spaces, Atmel Studio 6 further

simplifies embedded MCU designs to reduce development time and cost. Atmel Gallery

is an online apps store for development tools and embedded software. Atmel Spaces is a

cloud-based collaborative development workspace allowing you to host software and

hardware projects targeting Atmel MCUs.

In summary, standard integrated development environments (IDEs) are suited for

creating new software for an MCU project. By contrast, the Atmel Studio 6 IDP also:

Facilitates reuse of existing software and, by doing so, enables design differentiation.

Supports the product development process with easy access to integrated tools and

software extensions through Atmel Gallery. Reduces time to market by providing

advanced features, an extensible software eco-system, and powerful debug integration.

fig | Atmel Studio



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Chapter 5

The parts & Interfacing Following are the parts of the project.

5.1. Relay A relay is an electrically operated switch. Many relays use an electromagnet to

mechanically operate a switch, but other operating principles are also used, such as

solid-state relays. Relays are used where it is necessary to control a circuit by a low-

power signal (with complete electrical isolation between control and controlled

circuits), or where several circuits must be controlled by one signal. The first relays

were used in long distance telegraph circuits as amplifiers: they repeated the signal

coming in from one circuit and re-transmitted it on another circuit. Relays were used

extensively in telephone exchanges and early computers to perform logical operations.

A type of relay that can handle the high power required to directly control an electric

motor or other loads is called a contactor. Solid-state relays control power circuits with



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no moving parts, instead using a semiconductor device to perform switching. Relays

with calibrated operating characteristics and sometimes multiple operating coils are

used to protect electrical circuits from overload or faults; in modern electric power

systems these functions are performed by digital instruments still called "protective

relays".

Fig | Relay

A simple electromagnetic relay consists of a coil of wire wrapped around a soft iron

core, an iron yoke which provides a low reluctance path for magnetic flux, a movable

iron armature, and one or more sets of contacts (there are two in the relay pictured).

The armature is hinged to the yoke and mechanically linked to one or more sets of

moving contacts. It is held in place by a spring so that when the relay is de-energized

there is an air gap in the magnetic circuit. In this condition, one of the two sets of

contacts in the relay pictured is closed, and the other set is open. Other relays may have

more or fewer sets of contacts depending on their function. The relay in the picture also

has a wire connecting the armature to the yoke. This ensures continuity of the circuit

between the moving contacts on the armature, and the circuit track on the printed

circuit board (PCB) via the yoke, which is soldered to the PCB.

When an electric current is passed through the coil it generates a magnetic field that

activates the armature, and the consequent movement of the movable contact(s) either



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makes or breaks (depending upon construction) a connection with a fixed contact. If the

set of contacts was closed when the relay was de-energized, then the movement opens

the contacts and breaks the connection, and vice versa if the contacts were open. When

the current to the coil is switched off, the armature is returned by a force,

approximately half as strong as the magnetic force, to its relaxed position. Usually this

force is provided by a spring, but gravity is also used commonly in industrial motor

starters. Most relays are manufactured to operate quickly. In a low-voltage application

this reduces noise; in a high voltage or current application it reduces arcing.

When the coil is energized with direct current, a diode is often placed across the coil to

dissipate the energy from the collapsing magnetic field at deactivation, which would

otherwise generate a voltage spike dangerous to semiconductor circuit components.

Some automotive relays include a diode inside the relay case. Alternatively, a contact

protection network consisting of a capacitor and resistor in series (snubber circuit) may

absorb the surge. If the coil is designed to be energized with alternating current (AC), a

small copper "shading ring" can be crimped to the end of the solenoid, creating a small

out-of-phase current which increases the minimum pull on the armature during the AC

cycle.

A solid-state relay uses a thyristor or other solid-state switching device, activated by the

control signal, to switch the controlled load, instead of a solenoid. An optocoupler (a

light-emitting diode (LED) coupled with a photo transistor) can be used to isolate

control and controlled circuits.

5.3 The controller

Robotic arm controller comprises several electronic components. Here we will discuss the important parts of the circuit.

5.3.1 The microcontroller (Atmega 16)

The ATmega16 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega16 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.



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Fig.| Atmega 16 Pinout diagram. | PDIP package



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Fig.| Atmega 16 Pinout diagram. | TQFP package



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Fig.| Atmega 16 Pinout diagram. | MLF package



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Fig.31 | Block diagram of Atmega 8



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The AVR core combines a rich instruction set with 32 general purpose working

registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU),

allowing two independent registers to be accessed in one single instruction executed in

one clock cycle. The resulting architecture is more code efficient while achieving

throughputs up to ten times faster than conventional CISC microcontrollers. The

ATmega16 provides the following features: 16K bytes of In-System Programmable Flash

Program memory with Read-While-Write capabilities, 512 bytes EEPROM, 1K byte

SRAM, 32 general purpose I/O lines, 32 general purpose working registers, a JTAG

interface for Boundary scan, On-chip Debugging support and programming, three

flexible Timer/Counters with compare modes, Internal and External Interrupts, a serial

programmable USART, a byte oriented Two-wire Serial Interface, an 8-channel, 10-bit

ADC with optional differential input stage with programmable gain (TQFP package

only), a programmable Watchdog Timer with Internal Oscillator, an SPI serial port, and

six software selectable power saving modes. The Idle mode stops the CPU while

allowing the USART, Two-wire interface, A/D Converter, SRAM, Timer/Counters, SPI

port, and interrupt system to continue functioning. The Power-down mode saves the

register contents but freezes the Oscillator, disabling all other chip functions until the

next External Interrupt or Hardware Reset. In Power-save mode, the Asynchronous

Timer continues to run, allowing the user to maintain a timer base while the rest of the

device is sleeping. The ADC Noise Reduction mode stops the CPU and all I/O modules

except Asynchronous Timer and ADC, to minimize switching noise during ADC

conversions. In Standby mode, the crystal/resonator Oscillator is running while the rest

of the device is sleeping. This allows very fast start-up combined with low-power

consumption. In Extended Standby mode, both the main Oscillator and the

Asynchronous Timer continue to run. The device is manufactured using Atmel’s high

density non-volatile memory technology. The On chip ISP Flash allows the program

memory to be reprogrammed in-system through an SPI serial interface, by a

conventional non-volatile memory programmer, or by an On-chip Boot program

running on the AVR core. The boot program can use any interface to download the

application program in the Application Flash memory. Software in the Boot Flash

section will continue to run while the Application Flash section is updated, providing

true Re ad-While-Write operation. By combining an 8-bit RISC CPU with In-System Self-

Programmable Flash on a monolithic chip, the Atmel ATmega16 is a powerful



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microcontroller that provides a highly-flexible and cost-effective solution to many

embedded control applications. The ATmega16 AVR is supported with a full suite of

program and system development tools including: C compilers, macro assemblers,

program debugger/simulators, in-circuit emulators, and evaluation kits.

5.3.1.1 Pin Description of ATmega 16.

VCC: Digital supply voltage.

GND: Ground.

Port A (PA7..PA0): Port A serves as the analog inputs to the A/D

Converter. Port A also serves as an 8-bit bi-directional I/O port, if the A/D

Converter is not used. Port pins can provide internal pull-up resistors

(selected for each bit). The Port A output buffers have symmetrical drive

characteristics with both high sink and source capability. When pins PA0

to PA7 are used as inputs and are externally pulled low, they will source

current if the internal pull-up resistors are activated. The Port A pins are

tri-stated when a reset condition becomes active, even if the clock is not

running.

Port B (PB7..PB0): Port B is an 8-bit bi-directional I/O port with internal

pull-up resistors (selected for each bit). The Port B output buffers have

symmetrical drive characteristics with both high sink and source

capability. As inputs, Port B pins that are externally pulled low will source

current if the pull-up resistors are activated. The Port B pins are tri-stated

when a reset condition becomes active, even if the clock is not running.

Port C (PC7..PC0): Port C is an 8-bit bi-directional I/O port with internal

pull-up resistors (selected for each bit). The Port C output buffers have


capability. As inputs, Port C pins that are externally pulled low will source

current if the pull-up resistors are activated. The Port C pins are tri-stated

when a reset condition becomes active, even if the clock is not running. If

the JTAG interface is enabled, the pull-up resistors on pins PC5(TDI),

PC3(TMS) and PC2(TCK) will be activated even if a reset occurs.



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Port D (PD7..PD0): Port D is an 8-bit bi-directional I/O port with internal

pull-up resistors (selected for each bit). The Port D output buffers have


capability. As inputs, Port D pins that are externally pulled low will source

current if the pull-up resistors are activated. The Port D pins are tri-stated

when a reset condition becomes active, even if the clock is not running.

RESET: Reset Input. A low level on this pin for longer than the minimum

pulse length will generate a reset, even if the clock is not running.

XTAL1: Input to the inverting Oscillator amplifier and input to the

internal clock operating circuit.

XTAL2: Output from the inverting Oscillator amplifier.

AVCC: AVCC is the supply voltage pin for Port A and the A/D Converter. It

should be externally connected to VCC, even if the ADC is not used. If the

ADC is used, it should be connected to VCC through a low-pass filter.

AREF: AREF is the analog reference pin for the A/D Converter.

5.3 Serial Communication:

Serial communication is a way enables different equipments to communicate with their

outside world. It is called serial because the data bits will be sent in a serial way over a

single line.

A personal computer has a serial port known as communication port or COM Port used

to connect a modem for example or any other device, there could be more than one COM

Port in a PC.

Serial ports are controlled by a special chip called UART (Universal Asynchronous

Receiver Transmitter). Different applications use different pins on the serial port and

this basically depend of the functions required. If we need to connect our PC for

example to some other device by serial port, then we have to read instruction manual

for that device to know how the pins on both sides must be connected and the setting

required.



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5.3.1 Advantages of Serial Communication

Serial communication has some advantages over the parallel communication. One of the

advantages is transmission distance, serial link can send data to a remote device more

far then parallel link. Also the cable connection of serial link is simpler then parallel link

and uses less number of wires.

Serial link is used also for Infrared communication, now many devices such as laptops &

printers can communicate via inferred link.

5.3.2 Communication methods

There are two methods for serial communication, Synchronous & Asynchronous.

5.3.2.1 Synchronous serial communication:

In Synchronous serial communication the receiver must know when to “read” the next

bit coming from the sender, this can be achieved by sharing a clock between sender and

receiver.

In most forms of serial Synchronous communication, if there is no data available at a

given time to transmit, a fill character will be sent instead so that data is always being

transmitted. Synchronous communication is usually more efficient because only data

bits are transmitted between sender and receiver, however it will be more costly

because extra wiring and control circuits are required to share a clock signal between

the sender and receiver.

5.3.2.2 Asynchronous serial communication:

Asynchronous transmission allows data to be transmitted without the sender having to

send a clock signal to the receiver. Instead, special bits will be added to each word in

order to synchronize the sending and receiving of the data.

When a word is given to the UART for Asynchronous transmissions, a bit called the

“Start Bit” is added to the beginning of each word that is to be transmitted. The Start Bit



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is used to alert the receiver that a word of data is about to be sent, and to force the clock

in the receiver into synchronization with the clock in the transmitter.

Fig.32 | Example of serial data transmission

After the Start Bit, the individual bits of the word of data are sent, each bit in the word is

transmitted for exactly the same amount of time as all of the other bits

When the entire data word has been sent, the transmitter may add a Parity Bit that the

transmitter generates. The Parity Bit may be used by the receiver to perform simple

error checking. Then at least one Stop Bit is sent by the transmitter.

If the Stop Bit does not appear when it is supposed to, the UART considers the entire

word to be garbled and will report a Framing Error.

5.4 USB to Serial Converter

Since latest computers and laptops don’t come with serial ports. Because the popularity

of the USB. So we are using USB to serial converter. That makes our project ultra-

portable. A typical USB to serial converter creates a comport on the computer or laptop

and connects that comport to the external world.



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Fig.33 | USB to Serial Converter.

5.5 Software

The software we have got, is very easy to use. It requires the comport no. to

the project controller is attached. The complete operations of the project

can be controlled through the buttons provided in the software.

This software provide axis wise control.

Fig | The software Controller.



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Chapter 7

References

1. Atmega 16 data sheet.

2. USB to serial data sheet.

3. Serial communication manual of MS .net frame work

4. Serial communication manual of MATLAB.



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Appendix 1

The codding /*

* at8_pc_deviceCtrl.c

*

* Created: 27/Mar/2014 06:23:13

* Author: acer

*/

#include <avr/io.h>

#include "lcd.h"

/*Macros definition*/

#define BIT(x) (1 << (x)) //Set a particular bit mask

#define CHECKBIT(x,b) x&b //Checks bit status



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#define SETBIT(x,b) x|=b; //Sets the particular bit

#define CLEARBIT(x,b) x&=~b; //Sets the particular bit

#define TOGGLEBIT(x,b) x^=b; //Toggles the particular bit

#define TOGGLEBIT(x,b) x^=b; //Toggles the particular bit

/*Macros definition ends*/

void USARTInit(uint16_t ubrr_value)

{

//Set Baud rate

UBRRL = ubrr_value;

UBRRH = (ubrr_value>>8);

/*Set Frame Format

>> Asynchronous mode

>> No Parity

>> 1 StopBit

>> char size 8

*/

UCSRC=(1<<URSEL)|(3<<UCSZ0);

//Enable The receiver and transmitter

UCSRB=(1<<RXEN)|(1<<TXEN);

}



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//This function is used to read the available data

//from USART. This function will wait untill data is

//available.

char USARTReadChar()

{

//Wait untill a data is available

while(!(UCSRA & (1<<RXC)))

{

//Do nothing

}

//Now USART has got data from host

//and is available is buffer

return UDR;

}

//This fuction writes the given "data" to

//the USART which then transmit it via TX line

void USARTWriteChar(unsigned char data)

{

//Wait untill the transmitter is ready

while(!(UCSRA & (1<<UDRE)))

{

//Do nothing

}

//Now write the data to USART buffer

UDR=data;

}



Page 32

int main(void)

{

//InitLCD(LS_BLINK);

//LCDClear();

USARTInit(103);

//LCDWriteStringXY(0,0,"ROBO INDIA");

_delay_ms(500);

SETBIT(DDRC,BIT(7));

SETBIT(DDRD,BIT(2));



CLEARBIT(PORTC,BIT(5));

CLEARBIT(PORTD,BIT(2));



while(1)

{

//TODO:: Please write your application code

char data = USARTReadChar();

//LCDWriteIntXY(0,1,data,3);

if(data == 'A')

{

SETBIT(PORTC,BIT(5));

}

if(data == 'B')

{

CLEARBIT(PORTC,BIT(5));

}

if(data == 'C')

{

SETBIT(PORTD,BIT(2));



Page 33

}

if(data == 'D')

{


}

if(data == 'E')

{


}

if(data == 'F')

{


}

if(data == 'G')

{


}

if(data == 'H')

{


}

}

}

PC Based Industrial Automation With AVR Atmega 16 - Project Report

Documents

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