Robo Report for Robosapiens

8/6/2019 Robo Report for Robosapiens

1/64

AND

A REPORT

ON

ROBOTICS and Embedded C

BY:-

Jasmeet Singh

SIP/09/20090527/094515

Batch 3rd


2/64

ACKNOWLEDGEMENT

At the outset, I would like to thank Indian Institute of Technology, Guwahati

and Robosapiens India for giving me an opportunity to successfully

complete my training through their Summer Internship Program.

I am grateful to Coordinator, Mr. Pradeep Sharma for allowing me to pursue

my Training.

I would also like to express my heartfelt gratitude towards Mr. Shailabh

Suman and Mr. Sunil Kumar for their technical suggestions, constant

inspiration, guidance and criticism during the course of my training.

I will be failing in my duty if I dont thank Mr. Aman Sethi for his support

and guidance.


3/64

TABLE OF CONTENTS

1. Basic Electronics

1.1 Introduction to Transistors

1.1.1 Construction1.1.2 Connecting a BJT with External Circuit

1.1.3 NPN Transistor

1.1.4 PNP Transistor

1.1.5 Connecting BJTs to make Logic Gates

1.2 Operational Amplifiers

1.2.1 Non-Inverting Amplifier

1.2.2 Inverting Amplifier

1.2.3 Buffer

1.2.4 Differential Amplifier

1.2.5 Instrumentation Amplifier1.3 555 Timer IC

1.3.1 Astable

1.3.2 Monostable

1.3.3 Bistable

1.4 H-Bridge

1.5 Actuators

1.5.1 DC Motor

1.5.2 Stepper Motor

1.5.3 Servo Motor1.6 Digital to Analog Converter

1.7 Analog to Digital Converter

2. ATmega16

2.1 Features

2.2 Pin Descriptions

2.3 System Clock and Clock Options

2.4 I/O Ports

2.5 External Interrupts

2.6 8-Bit Timer/Counter0

2.7 16-Bit Timer/Counter12.7 8-Bit Timer/Counter2

2.8 Analog to Digital Converter

2.9 Some Codes with ATmega16


4/64

3. Image Processing

3.1Some Common Formats

3.2Sampling

3.3Quantization

3.4Functions in MATLAB for Image Processing

3.5Some Codes for Image Processing in MATLAB

4. Parallel Port


5/64

Basic Electrical and Electronics

Introduction To Transistors

A Bipolar Junction Transistor (BJT) is widely used in discrete circuits as well as in IC

design, both analog and digital. Its main applications are in amplification of small signals,

and in switching digital logic signals. In a BJT both majority and minority carriers play a

role in the operation of the transistor, hence the term bipolar.

Construction

The principle of operation of the two transistor types, NPN and PNP, is exactly the same.

The only difference being in the biasing (base current) and the polarity of the power

supply for each type.


6/64

The construction and circuit symbols for both the NPN and PNP bipolar transistor are

shown above with the arrow in the circuit symbol always showing the direction of

conventional current flow between the base and emitter terminals.

Connecting a BJT with External Circuit

There are basically three possible ways to connect a Bipolar Transistor within an

electronic circuit with each method of connection responding differently to its input

signal as the static characteristics of the transistor vary with each circuit arrangement.

1. Common Base Configuration - has Voltage Gain but no Current Gain.

2. Common Emitter Configuration - has both Current and Voltage Gain.

3. Common Collector Configuration - has Current Gain but no Voltage Gain.

The Common Base Configuration

As its name suggests, in the Common Base or Grounded Base configuration, the BASE

connection is common to both the input signal AND the output signal with the input

signal being applied between the base and the emitter terminals. The corresponding

output signal is taken from between the base and the collector terminals as shown with

the base terminal grounded or connected to a fixed reference voltage point. The input

current flowing into the emitter is quite large as its the sum of both the base current and

collector current respectively therefore, the collector current output is less than the

emitter current input resulting in a Current Gain for this type of circuit of less than "1", or

in other words it "Attenuates" the signal.

The Common Base Amplifier Circuit


7/64

This type of amplifier configuration is a non-inverting voltage amplifier circuit, in that

the signal voltages Vin and Vout are In-Phase. This type of arrangement is not very

common due to its unusually high voltage gain characteristics. Its Output characteristics

represent that of a forward biased diode while the Input characteristics represent that of

an illuminated photo-diode. Also this type of configuration has a high ratio of Output to

Input resistance or more importantly "Load" resistance (RL) to "Input" resistance (Rin)

giving it a value of "Resistance Gain". Then the Voltage Gain for a common base can

therefore be given as:

Common Base Voltage Gain

The Common Base circuit is generally only used in single stage amplifier circuits such as

microphone pre-amplifier or RF radio amplifiers due to its very good high frequency

response.

The Common Emitter Configuration

In the Common Emitter or Grounded Emitter configuration, the input signal is applied

between the base, while the output is taken from between the collector and the emitter as

shown. This type of configuration is the most commonly used circuit for transistor based

amplifiers and which represents the "normal" method of connection. The common emitter

amplifier configuration produces the highest voltage, current and power gain of all the

three bipolar transistor configurations. This is mainly because the input impedance is

LOW as it is connected to a forward-biased junction, while the output impedance is

HIGH as it is taken from a reverse-biased junction.


8/64

The Common Emitter Amplifier Circuit

In this type of configuration, the current flowing out of the transistor must be equal to the

currents flowing into the transistor as the emitter current is given as Ie = Ic + Ib. Also, as

the load resistance (RL) is connected in series with the collector, the Current gain of the

Common Emitter Transistor Amplifier is quite large as it is the ratio of Ic/Ib and is given

the symbol of Beta, (). Since the relationship between these three currents is determined

by the transistor itself, any small change in the base current will result in a large change

in the collector current. Then, small changes in base current will thus control the current

in the Emitter/Collector circuit.

By combining the expressions for both Alpha, and Beta, the mathematical

relationship between these parameters and therefore the current gain of the amplifier can

be given as:

Where: "Ic" is the current flowing into the collector terminal, "Ib" is the current flowing

into the base terminal and "Ie" is the current flowing out of the emitter terminal.


9/64

Then to summarize, this type of bipolar transistor configuration has a greater input

impedance, Current gain and Power gain than that of the common base configuration but

its Voltage gain is much lower. The common emitter is an inverting amplifier circuit

resulting in the output signal being 180o out of phase with the input voltage signal.

The Common Collector Configuration

In the Common Collector or Grounded Collector configuration, the collector is now

common and the input signal is connected to the base, while the output is taken from the

emitter load as shown. This type of configuration is commonly known as a Voltage

Follower or Emitter Follower circuit. The emitter follower configuration is very useful

for impedance matching applications because of the very high input impedance, in the

region of hundreds of thousands of Ohms, and it has relatively low output impedance.

The Common Collector Amplifier Circuit

The common emitter configuration has a current gain equal to the value of the transistor

itself. In the common collector configuration the load resistance is situated in series with

the emitter so its current is equal to that of the emitter current. As the emitter current is

the combination of the collector AND base currents combined, the load resistance in this

type of amplifier configuration also has both the collector current and the input current of

the base flowing through it. Then the current gain of the circuit is given as:


10/64

This type of bipolar transistor configuration is a non-inverting amplifier circuit in that the

signal voltages of Vin and Vout are "In-Phase". It has a voltage gain that is always less

than "1" (unity). The load resistance of the common collector amplifier configuration

receives both the base and collector currents giving a large current gain (as with the

Common Emitter configuration) therefore, providing good current amplification with

very little voltage gain.

NPN Transistors

We know that the transistor is a "CURRENT" operated device and that a large current

(Ic) flows freely through the device between the collector and the emitter terminals.

However, this only happens when a small biasing current (Ib) is flowing into the base


11/64

terminal of the transistor thus allowing the base to act as a sort of current control input.

The ratio of these two currents (Ic/Ib) is called the DC Current Gain of the device and is

given the symbol of hfe or nowadays Beta, (). Beta has no units as it is a ratio. Also, the

current gain from the emitter to the collector terminal, Ic/Ie, is called Alpha, (), and is a

function of the transistor itself. As the emitter current Ie is the product of a very small

base current to a very large collector current the value of this parameter is very close to

unity, and for a typical low-power signal transistor this value ranges from about 0.950 to

0.999.

and Relationships

By combining the two parameters and we can produce two mathematical expressions

that gives the relationship between the different currents flowing in the transistor.

The values of Beta vary from about 20 for high current power transistors to well over

1000 for high frequency low power type bipolar transistors. The equation for Beta can

also be re-arranged to make Ic as the subject, and with zero base current (Ib = 0) the

resultant collector current Ic will also be zero, ( x 0). Also when the base current is high


12/64

the corresponding collector current will also be high resulting in the base current

controlling the collector current. One of the most important properties of the Bipolar

Junction Transistor is that a small base current can control a much larger collector

current.

PNP Transistors

PNP Transistors are the exact opposite to the NPN Transistors device we looked at

previously. Basically, in this type of transistor construction the two diodes are reversed

with respect to the NPN type, with the arrow, which also defines the Emitter terminal this

time pointing inwards in the transistor symbol. Also, all the polarities are reversed which

means that PNP Transistors "sink" current as opposed to the NPN transistor which

"sources" current. Then, PNP Transistors use a small output base current and a negative

base voltage to control a much larger emitter-collector current. The construction of a PNP

transistor consists of two P-type semiconductor materials either side of the N-type

material as shown below.

PNP Transistor Configuration

PNP Transistors have very similar characteristics to their NPN bipolar cousins, except

that the polarities (or biasing) of the current and voltage directions are reversed for any

one of the possible three configurations looked at in the first tutorial, Common Base,

Common Emitter and Common Collector. Generally, PNP Transistors require a negative


13/64

(-ve) voltage at their Collector terminal with the flow of current through the emitter-

collector terminals being Holes as opposed to Electrons for the NPN types. Because the

movement of holes across the depletion layertends to be slower than for electrons, PNP

transistors are generally more slower than their equivalent NPN counterparts when

operating.

To cause the Base current to flow in a PNP transistor the Base needs to be more negative

than the Emitter (current must leave the base) by approx 0.7 volts for a silicon device or

0.3 volts for a germanium device with the formulas used to calculate the Base resistor,

Base current or Collector current are the same as those used for an equivalent NPN

transistor and is given as.

Connecting BJTs to make Logic Gates

AND gate - Here you need to connect two transistors in a way that the output is high only

when both inputs are high.1


14/64

OR gate - This is simpler, you connect them in a way that when either input is high the

output will be high.

NOT gate - This is the simplest one to build, as mentioned in the introduction, you only

need one transistor for this one.


15/64

OPERATIONAL AMPLIFIERS

We have built voltage and current amplifiers using transistors. Circuits of this kind with

nice properties (high gain and high input impedance, for example), packaged as

integrated circuits (ICs), are called operational amplifiers or op amps. They are called

``operational'' amplifiers, because they can be used to perform arithmetic operations

(addition, subtraction, multiplication) with signals. In fact, op amps can also be used to

integrate (calculate the areas under) and differentiate (calculate the slopes of) signals.

A circuit model of an operational amplifier (op amp) with gain and input and output

resistances Rin and Rout is shown above. A circuit model of an operational amplifier is

shown in figure above. The output voltage of the op amp is linearly proportional to the

voltage difference between the input terminals v+-v- by a factor of the gain . However,

the output voltage is limited to the range Vcc < v


16/64

infinite gain is that, if the output voltage is within the finite linear region, we must have

v+=v-. A real op amp has a gain on the range 103-105 (depending on the type), and hence

actually maintains a very small difference in input terminal voltages when operating in its

linear region. For most applications, we can get away with assuming .

Non-Inverting Amplifier

Circuit

Voltage Gain

Like the inverting amplifier, the op-amp device simplifies the design of an amplifier

stage. How? The gain of the stage depends on external resistors, not the internal gain of

the op amp itself. The output voltage is determined by the input voltage and the ratio of

the feedback resistors plus one.

+Vcc


17/64

Inverting Amplifier

Circuit

Voltage Gain

How does an op-amp device simplify the design of an amplifier? The voltage gain for the

inverting configuration is set by the ratio of the feedback resistors R1 and R2, not the

internal gain of the op-amp itself.

Buffer

The buffer has an output that exactly mirrors the input (assuming it's within range of the

voltage rails), so it looks kind of useless at first.

However, the buffer is an extremely useful circuit, since it helps to solve many

impedance issues. The input impedance of the op-amp buffer is very high: close to

infinity. And the output impedance is very low: just a few ohms.


18/64

This means we can use buffers to help chain together sub-circuits in stages without

worrying about impedance problems. The buffer gives benefits similar to those of the

emitter follower we looked at with transistors, but tends to work more ideally.

Differential Amplifier

Circuit

The differential amplifier has a unique feature that many circuits dont have - two inputs.

This circuit amplifies the difference between its input terminals. Other circuits with one

input actually have another input the ground potential. But, in cases where a signal

source (like a sensor) has both of its terminals biased at several volts above ground, you

need to amplify the difference between the terminals. What about noise that adds an

unwanted voltage equally to both terminals of a sensor? The differential amp rejects the

noise and rescues the signal.

Voltage Gain

If you keep the following resistor ratios equal, R2/R1 = R4/R3, the voltage gain looks

like

What about signals common (or equal) at both inputs Vin+ and Vin-? The equation above

tells you the output Vo should be zero! This Common Mode Rejection (CMR) is useful

but not perfect! It depends on the op amp device itself and matching of the resistor

values.


19/64

Instrumentation Amplifier

An instrumentation (or instrumentational) amplifier is a type ofdifferential amplifierthat

has been outfitted with input buffers, which eliminate the need for input impedance

matching and thus make the amplifier particularly suitable for use in measurement and

test equipment.

The most commonly used instrumentation amplifier circuit is shown in the figure. The

gain of the circuit is

The ideal common-mode gain of an instrumentation amplifier is zero.

Vout =(1+ 2R1 ) R3

V2-V1 Rgain R2
http://en.wikipedia.org/wiki/Differential_amplifierhttp://en.wikipedia.org/w/index.php?title=Test_equipment&action=edit&redlink=1http://en.wikipedia.org/wiki/Differential_amplifierhttp://en.wikipedia.org/w/index.php?title=Test_equipment&action=edit&redlink=1


20/64

555 Timer IC

The 555 Timer IC is an integrated circuit (chip) implementing a variety of timer and

multivibratorapplications. original name was the SE555/NE555 and was called "The IC

Time Machine".[1]

The 555 gets its name from the three 5-kohm resistors used in typical

early implementations.[2] It is still in wide use, thanks to its ease of use, low price and

good stability. Depending on the manufacturer, it includes over 20 transistors, 2 diodes

and 15 resistors on a silicon chip installed in an 8-pin mini dual-in-line package (DIP-8).

The 555 has three operating modes:

Monostable mode: in this mode, the 555 functions as a "one-shot". Applications

include timers, missing pulse detection, bouncefree switches, touch switches,

frequency divider, capacitance measurement, pulse-width modulation (PWM) etc

Astable - free running mode: the 555 can operate as an oscillator. Uses include

LED and lamp flashers, pulse generation, logic clocks, tone generation, security

alarms,pulse position modulation, etc.
http://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Timerhttp://en.wikipedia.org/wiki/Multivibratorhttp://en.wikipedia.org/wiki/555_timer_IC#cite_note-0%23cite_note-0http://en.wikipedia.org/wiki/Ohmhttp://en.wikipedia.org/wiki/555_timer_IC#cite_note-1%23cite_note-1http://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Resistorhttp://en.wikipedia.org/wiki/DIP-8http://en.wikipedia.org/wiki/Monostablehttp://en.wikipedia.org/wiki/Astablehttp://en.wikipedia.org/wiki/Oscillatorhttp://en.wikipedia.org/wiki/LEDhttp://en.wikipedia.org/wiki/Pulse_position_modulationhttp://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Timerhttp://en.wikipedia.org/wiki/Multivibratorhttp://en.wikipedia.org/wiki/555_timer_IC#cite_note-0%23cite_note-0http://en.wikipedia.org/wiki/Ohmhttp://en.wikipedia.org/wiki/555_timer_IC#cite_note-1%23cite_note-1http://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Resistorhttp://en.wikipedia.org/wiki/DIP-8http://en.wikipedia.org/wiki/Monostablehttp://en.wikipedia.org/wiki/Astablehttp://en.wikipedia.org/wiki/Oscillatorhttp://en.wikipedia.org/wiki/LEDhttp://en.wikipedia.org/wiki/Pulse_position_modulation


21/64

Bistable mode orSchmitt trigger: the 555 can operate as a flip-flop, if the DIS pin

is not connected and no capacitor is used. Uses include bouncefree latched

switches, etc.

Schematic symbol

The connection of the pins is as follows:

Nr. Name Purpose

1 GND Ground, low level (0V)

2 TRIG A short pulse high-to-low on the trigger starts the timer

3 OUT During a timing interval, the output stays at +VCC

4 RESET A timing interval can be interrupted by applying a reset pulse to low (0V)

5 CTRL Control voltage allows access to the internal voltage divider (2/3 VCC)

6 THR The threshold at which the interval ends (it ends if U.thr 2/3 VCC)

7 DISConnected to a capacitor whose discharge time will influence the timing

interval

8 V+, VCC The positive supply voltage which must be between 3 and 15 V
http://en.wikipedia.org/wiki/Bistablehttp://en.wikipedia.org/wiki/Schmitt_triggerhttp://en.wikipedia.org/wiki/Flip-flop_(electronics)http://en.wikipedia.org/wiki/Vcchttp://en.wikipedia.org/wiki/Vcchttp://en.wikipedia.org/wiki/Bistablehttp://en.wikipedia.org/wiki/Schmitt_triggerhttp://en.wikipedia.org/wiki/Flip-flop_(electronics)http://en.wikipedia.org/wiki/Vcc


22/64

555 Astable

An astable circuit produces a 'square wave',

this is a digital waveform with sharp

transitions between low (0V) and

high (+Vs). Note that the durations

of the low and high states may be

different.

The circuit is called an astable because it is

not stable in any state: the output is

continually changing between 'low' and

'high'.

The time period (T) of the square wave is

the time for one complete cycle, but it is

usually better to consider frequency (f)

which is the number of cycles per second.

T = 0.7 (R1 + 2R2) C1 and f =1.4

(R1 + 2R2) C1

T = time period in seconds (s)

f = frequency in hertz (Hz)

R1 = resistance in ohms ( )


C1 = capacitance in farads (F)

555 astable output, a square wave

(Tm and Ts may be different)

555 astable circuit
http://www.kpsec.freeuk.com/acdc.htm#propshttp://www.kpsec.freeuk.com/acdc.htm#propshttp://www.kpsec.freeuk.com/acdc.htm#propshttp://www.kpsec.freeuk.com/acdc.htm#props


23/64

The time period can be split into two parts: T = Tm + Ts

Mark time (output high): Tm = 0.7 (R1 + R2) C1

Space time (output low): Ts = 0.7 R2 C1

Many circuits require Tm and Ts to be almost equal; this is achieved if R2 is much larger

than R1.

For a standard astable circuit Tm cannot be less than Ts, but this is not too restricting

because the output can both sink and source current.

Astable operation

With the output high (+Vs) the capacitor C1 is charged by current flowing through R1

and R2. The threshold and trigger inputs monitor the capacitor voltage and when it

reaches 2/3Vs (threshold voltage) the output becomes low and the discharge pin is

connected to 0V.

The capacitor now discharges with current flowing through R2 into the discharge pin.

When the voltage falls to 1/3Vs (trigger voltage) the output becomes high again and the

discharge pin is disconnected, allowing the capacitor to start charging again.

This cycle repeats continuously unless the reset input is connected to 0V which forces the

output low while reset is 0V.

An astable can be used to provide the clock signal for circuits such as counters.

A low frequency astable (< 10Hz) can be used to flash an LED on and off, higher

frequency flashes are too fast to be seen clearly. Driving a loudspeaker or piezo


24/64

transducer with a low frequency of less than 20Hz will produce a series of 'clicks' (one

for each low/high transition) and this can be used to make a simple metronome.

An audio frequency astable (20Hz to 20kHz) can be used to produce a sound from a

loudspeaker or piezo transducer. The sound is suitable for buzzes and beeps. The natural

(resonant) frequency of most piezo transducers is about 3kHz and this will make them

produce a particularly loud sound.

Duty cycle

The duty cycle of an astable circuit is the proportion of the complete cycle for which the

output is high (the mark time). It is usually given as a percentage.

For a standard 555/556 astable circuit the mark time (Tm) must be greater than the space

time (Ts), so the duty cycle must be at least 50%:

Duty cycle =Tm

=R1 + R2

Tm + Ts R1 + 2R2

To achieve a duty cycle of less than 50% a diode

can be added in parallel with R2 as shown in the

diagram. This bypasses R2 during the charging

(mark) part of the cycle so that Tm depends only

on R1 and C1:

Tm = 0.7 R1 C1 (ignoring 0.7V across

diode)

Ts = 0.7 R2 C1 (unchanged)

Duty cycle

with diode =

Tm=

R1

Tm + Ts R1 + R2

555 astable circuit with diode across R2


25/64

555 Monostable

A monostable circuit produces a

single output pulse when triggered. It

is called a monostable because it is

stable in just one state: 'output low'.

The 'output high' state is temporary.

The duration of the pulse is called the

time period (T) and this is determined

by resistor R1 and capacitor C1:

time period, T = 1.1 R1 C1

T = time period in seconds (s)


C1 = capacitance in farads (F)

The maximum reliable time period is about 10 minutes.

Why 1.1? The capacitor charges to 2/3 = 67% so it is a bit longer than the time constant

(R1 C1) which is the time taken to charge to 63%.

Choose C1 first (there are relatively few values available).

Choose R1 to give the time period you need. R1 should be in the range 1k to

1M , so use a fixed resistor of at least 1k in series if R1 is variable.

Beware that electrolytic capacitor values are not accurate, errors of at least 20%

are common.

Beware that electrolytic capacitors leak charge which substantially increases the

time period if you are using a high value resistor - use the formula as only a very

rough guide!

For example the Timer Project should have a maximum time period of 266s

(about 4 minutes), but many electrolytic capacitors extend this to about 10

minutes!

555 monostable output, a single pulse

555 monostable circuit with manual trigger
http://www.kpsec.freeuk.com/capacit.htm#timeconstanthttp://www.kpsec.freeuk.com/projects/timer.htmhttp://www.kpsec.freeuk.com/capacit.htm#timeconstanthttp://www.kpsec.freeuk.com/projects/timer.htm


26/64

Monostable operation

The timing period is triggered (started) when the trigger input (555 pin 2) is less than

1/3 Vs, this makes the output high (+Vs) and the capacitor C1 starts to charge through

resistor R1. Once the time period has started further trigger pulses are ignored.

The threshold input (555 pin 6) monitors the voltage across C1 and when this reaches

2/3 Vs the time period is over and the output becomes low. At the same time discharge

(555 pin 7) is connected to 0V, discharging the capacitor ready for the next trigger.

The reset input (555 pin 4) overrides all other inputs and the timing may be cancelled at

any time by connecting reset to 0V, this instantly makes the output low and discharges

the capacitor. If the reset function is not required the reset pin should be connected to

+Vs.

555 Bistable (flip-flop) - a

memory circuit

The circuit is called a bistable because

it is stable in two states: output high

and output low. It is also known as a

'flip-flop'.

It has two inputs:

555 bistable circuit


27/64

Trigger (555 pin 2) makes the output high.

Trigger is 'active low', it functions when < 1/3 Vs.

Reset (555 pin 4) makes the output low.

Reset is 'active low', it resets when < 0.7V.

The power-on reset, power-on trigger and edge-triggering circuits can all be used as

described above for the monostable.

H-Bridge

The term "H-bridge" is derived from the typical graphical representation of such a circuit.

An H-bridge is built with four switches. When the switches S1 and S4 are closed (and S2

and S3 are open) a positive voltage will be applied across the motor. By opening S1 andS4 switches and closing S2 and S3 switches, this voltage is reversed, allowing reverse

operation of the motor.
http://www.kpsec.freeuk.com/555timer.htm#monostable%23monostablehttp://www.kpsec.freeuk.com/555timer.htm#monostable%23monostable


28/64

Operation

The H-Bridge arrangement is generally used to reverse the polarity of the motor, but can

also be used to 'brake' the motor, where the motor comes to a sudden stop, as the motor's

terminals are shorted, or to let the motor 'free run' to a stop, as the motor is effectively

disconnected from the circuit. The following table summarizes operation.

S1 S2 S3 S4 Result

1 0 0 1 Motor moves right

0 1 1 0 Motor moves left

0 0 0 0 Motor free runs

0 1 0 1 Motor brakes

1 0 1 0 Motor brakes

Actuators

An actuator is a mechanical device for moving or controlling a mechanism or system.

An actuator typically is a mechanical device that takes energy, usually created by air,

electricity, or liquid, and converts that into some kind of motion.

DC Motor

A DC motor is an electric motorthat runs on direct current (DC) electricity
http://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Direct_current


29/64

How a DC motor works

A DC motor works by converting electrical energy into mechanical work. This is

accomplished by forcing current through a coil and producing a magnetic field that spins

the motor. The simplest DC motor is a single coil apparatus, used here to discuss the DC

motor theory.

The voltage source forces current through the coil via sliding contacts or brushes that are

connected to the DC source. These brushes are found on the end of the coil wires and

make a temporary electrical connection with the voltage source. In this motor, the

brushes will make a connection every 180 degrees and current will then flow through the

coil wires. At 0 degrees, the brushes are in contact with the voltage source and current is

flowing. The current that flows through wire segment C-D interacts with the magnetic

field that is present and the result is an upward force on the segment. The current that

flows through segment A-B has the same interaction, but the force is in the downward

direction. Both forces are of equal magnitude, but in opposing directions since the

direction of current flow in the segments is reversed with respect to the magnetic field. At

180 degrees, the same phenomenon occurs, but segment A-B is forced up and C-D is

forced down. At 90 and 270-degrees, the brushes are not in contact with the voltage

source and no force is produced. In these two positions, the rotational kinetic energy of

the motor keeps it spinning until the brushes regain contact.

One drawback to the motor is the large amount of torque ripple that it has. The reason for

this excessive ripple is because of the fact that the coil has a maximum force pushing on

it only at the 90 and 270 degree positions. The rest of the time the coil spins on its own

and the torque drops to zero. The torque curveproduced by this single coil, as more coils

are added to the motor, the torque curve is smoothed out.

The resulting torque curve never reaches the zero point and the average torque for the

motor is greatly increased. As more and more coils are added, the torque curve
http://en.wikipedia.org/wiki/Electrical_energyhttp://en.wikipedia.org/wiki/Mechanical_workhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Voltage_sourcehttp://en.wikipedia.org/wiki/Electrical_connectionhttp://en.wikipedia.org/wiki/Rotational_energyhttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Single_coilhttp://en.wikipedia.org/wiki/Electrical_energyhttp://en.wikipedia.org/wiki/Mechanical_workhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Voltage_sourcehttp://en.wikipedia.org/wiki/Electrical_connectionhttp://en.wikipedia.org/wiki/Rotational_energyhttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Single_coil


30/64

approaches a straight line and has very little torque ripple and the motor runs much more

smoothly. Another method of increasing the torque and rotational speed of the motor is to

increase the current supplied to the coils. This is accomplished by increasing the voltage

that is sent to the motor, thus increasing the current at the same time.

Stepper Motor

A stepper motor (or step motor) is abrushless, synchronous electric motorthat can divide

a full rotation into a large number of steps. The motor's position can be controlled

precisely, without any feedback mechanism (see Open-loop controller). Stepper motors

are similar to switched reluctance motors (which are very large stepping motors with a

reduced pole count, and generally are closed-loop commutated.).

Stepper motors utilize a doubly-salient topology, which means they have "teeth" on both

the rotor and stator. Torque is generated by alternately magnetizing the stator teeth

electrically, and the permanent magnet rotor teeth try to line up with the stator teeth.

There are many different configurations of stepper motors, and even more diverse ways

to drive them. The most common stator configuration consists of two coils (A and B).

These coils are arranged around the circumference of the stator in such a way that if they

are driven with square waves which have a quadrature phase relationship between them,

the motor will rotate. To make the motor rotate in the opposite direction, simply reverse

the phase relationship between the A and B signals. A transition of either square wave

causes the rotor to move by a small amount, or a "STEP". Thus, the name "stepper

motor". The size of this step is dependent on the teeth arrangement of the motor, but a

common value is 1.8 degrees, or 200 steps per revolution. Speed control is achieved by

simply varying the frequency of the squarewaves.

Because stepper motors can be driven with square waves, they are easily controlled by

inexpensive digital circuitry and do not even require PWM. For this reason, stepper

motors have often been inappropriately referred to as "digital motors". However, by

utilizing power modulation techniques to change the quadrature squarewaves into sine

and cosine waveforms, even MORE step resolution is possible. This is called "micro-
http://en.wikipedia.org/wiki/Rotational_speedhttp://en.wikipedia.org/wiki/Brushless_DC_electric_motorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Open-loop_controllerhttp://en.wikipedia.org/wiki/Reluctance_motorhttp://en.wikipedia.org/wiki/Rotational_speedhttp://en.wikipedia.org/wiki/Brushless_DC_electric_motorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Open-loop_controllerhttp://en.wikipedia.org/wiki/Reluctance_motor


31/64

stepping", where each discrete change in the sine and cosine levels constitutes one

microstep. Theoretically, there is no limit to the position resolution achievable with

micro-stepping, but in reality, it is limited by the motor mechanical and electrical

tolerances. Some stepper motors are designed specifically for micro-stepping, and consist

of tightly matched impedances between the A and B coils, and tighter machining

tolerances on the teeth, at the expense of higher cost.

Servo Motor

Servos are DC motorswith built in gearing and feedback control loop circuitry. And no

motor drivers required! Servos are extremely popular with robot, RC plane, and RC boat

builders. Most servo motors can rotate about 90 to 180 degrees. Some rotate through afull 360 degrees or more. However, servos are unable to continually rotate, meaning they

can't be used for driving wheels (unlessmodified), but their precision positioning makes

them ideal forrobot arms and legs, rack and pinion steering, and sensor scanners to name

a few. Since servos are fully self contained, the velocity and angle control loops are very

easy to impliment, while prices remain very affordable. To use a servo, simply connect
http://www.societyofrobots.com/actuators_dcmotors.shtmlhttp://www.societyofrobots.com/actuators_dcmotors.shtmlhttp://www.societyofrobots.com/actuators_modifyservo.shtmlhttp://www.societyofrobots.com/actuators_modifyservo.shtmlhttp://www.societyofrobots.com/robot_arm_tutorial.shtmlhttp://www.societyofrobots.com/actuators_dcmotors.shtmlhttp://www.societyofrobots.com/actuators_modifyservo.shtmlhttp://www.societyofrobots.com/robot_arm_tutorial.shtml


32/64

the black wire to ground, the red to a 4.8-6V source, and the yellow/white wire to a signal

generator (such as from yourmicrocontroller). Vary the square wave pulse width from 1-

2ms and your servo is now position/velocity controlled.

DAC

R-2R

The below diagram is an 8-bit digital-to-analog converter that utilizes a resister ladder

network to divide current with equal current sources, and an operational amplifier to sum

these currents and convert them into an output voltage.

ADC

Successive Approximation

Successive approximation ADC is a type of analog-to-digital converter that converts a

continuous analog waveform into a discrete digital representation via a binary search

through all possible quantization levels before finally converging upon a digital output

for each conversion.
http://www.societyofrobots.com/microcontroller_tutorial.shtmlhttp://en.wikipedia.org/wiki/Analog-to-digital_converterhttp://en.wikipedia.org/wiki/Analog_signalhttp://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Binary_searchhttp://en.wikipedia.org/wiki/Quantization_(signal_processing)http://www.societyofrobots.com/microcontroller_tutorial.shtmlhttp://en.wikipedia.org/wiki/Analog-to-digital_converterhttp://en.wikipedia.org/wiki/Analog_signalhttp://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Binary_searchhttp://en.wikipedia.org/wiki/Quantization_(signal_processing)


33/64

DAC = digital-to-analog converter

EOC = end of conversion

SAR = successive approximation register

S/H = sample and hold circuit

Vin = input voltage

Vref = reference voltage


34/64

ATMEGA 16

Features

High-performance, Low-power AVR 8-bit Microcontroller

Advanced RISC Architecture 131 Powerful Instructions Most Single-clock Cycle Execution

32 x 8 General Purpose Working Registers

Up to 16 MIPS Throughput at 16 MHz

On-chip 2-cycle Multiplier

Nonvolatile Program and Data Memories

16K Bytes of In-System Self-Programmable Flash

1K Byte Internal SRAM

JTAG (IEEE std. 1149.1 Compliant) Interface

Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface

Peripheral Features

Two 8-bit Timer/Counters with Separate Prescalers and Compare Modes

One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode

Real Time Counter with Separate Oscillator

Four PWM Channels

8-channel, 10-bit ADC

8 Single-ended Channels

7 Differential Channels in TQFP Package Only

Programmable Serial USART

Master/Slave SPI Serial Interface

Programmable Watchdog Timer with Separate On-chip Oscillator

On-chip Analog Comparator

Special Microcontroller Features Internal Calibrated RC Oscillator

External and Internal Interrupt Sources

Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby and

Extended Standby

I/O and Packages


35/64

32 Programmable I/O Lines

40-pin PDIP, 44-lead TQFP, and 44-pad MLF

Operating Voltages

4.5 - 5.5V

Speed Grades

0 - 16 MHz


36/64

Pin DescriptionsVCC 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.

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

Port C (PC7..PC0) Port C is an 8-bit bi-directional I/O port. 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.Port D (PD7..PD0) Port D is an 8-bit bi-directional I/O port.

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.


37/64

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.

System Clock and

Clock OptionsClock Systems and their

DistributionCPU Clock clkCPU The CPU clock is routed to parts of the system concerned with

operation of the AVR

core. Examples of such modules are the General Purpose Register File, the Status

Register

and the data memory holding the Stack Pointer. Halting the CPU clock inhibits the

core from performing general operations and calculations.

I/O Clock clkI/O The I/O clock is used by the majority of the I/O modules, like

Timer/Counters, SPI, and

USART. The I/O clock is also used by the External Interrupt module, but note that some

external interrupts are detected by asynchronous logic, allowing such interrupts to be

detected even if the I/O clock is halted. Also note that address recognition in the TWI

module is carried out asynchronously when clkI/O is halted, enabling TWI address

reception

in all sleep modes.

Flash Clock clkFLASH The Flash clock controls operation of the Flash interface. The

Flash clock is usually

active simultaneously with the CPU clock.

Asynchronous Timer Clock


38/64

clkASY

The Asynchronous Timer clock allows the Asynchronous Timer/Counter to be clocked

directly from an external 32 kHz clock crystal. The dedicated clock domain allows using

this Timer/Counter as a real-time counter even when the device is in sleep mode.

ADC Clock clkADC The ADC is provided with a dedicated clock domain. This allows

halting the CPU and

I/O clocks in order to reduce noise generated by digital circuitry. This gives more

accurate

ADC conversion results.


39/64

I/O Ports


40/64


41/64

The following code example shows how to set port B pins 0 and 1 high, 2 and 3 low, and

define the port pins from 4 to 7 as input with pull-ups assigned to port pins 6 and 7.

C Code Example(1)

unsigned char i;

...

/*Define pull-ups and set outputs high */

/*Define directions for port pins */

PORTB = (1


42/64

External Interrupts

MCU Control Register(MCUCR)

ISC11, ISC10: Interrupt Sense Control 1 Bit 1 and Bit 0

ISC01, ISC00: Interrupt Sense Control 0 Bit 1 and Bit 0

MCU Control and Status

Register MCUCSR

ISC2: Interrupt Sense Control 2

8-bit Timer/Counter0Timer/Counter0 is a general purpose, single channel, 8-bit Timer/Counter module.

The Timer/Counter (TCNT0) and Output Compare Register (OCR0) are 8-bit registers.

Interrupt request (abbreviated to Int.Req. in the figure) signals are all visible in the Timer

Interrupt Flag Register (TIFR). All interrupts are individually masked with the Timer

Interrupt Mask register (TIMSK).

Output Compare UnitThe 8-bit comparator continuously compares TCNT0 with the

Output Compare Register

(OCR0). Whenever TCNT0 equals OCR0, the comparator signals a match. A match will

set the Output Compare Flag (OCF0) at the next timer clock cycle. If enabled (OCIE0 =

1 and Global Interrupt Flag in SREG is set), the Output Compare Flag generates an

output

compare interrupt. The OCF0 flag is automatically cleared when the interrupt is

executed. Alternatively, the OCF0 flag can be cleared by software by writing a logical

one to its I/O bit location.


43/64

8-bit Timer/Counter

Register Description

Timer/Counter Control

Register TCCR0

FOC0: Force Output Compare

WGM01:0: Waveform Generation Mode

COM01:0: Compare Match Output Mode

CS02:0: Clock Select

Timer/Counter Interrupt Mask

Register TIMSK

OCIE0: Timer/Counter0 Output Compare Match Interrupt Enable

TOIE0: Timer/Counter0 Overflow Interrupt Enable


44/64

16-bit Timer/Counter1The 16-bit Timer/Counter unit allows accurate program execution timing (event

management),

wave generation, and signal timing measurement.

The following code examples show how to access the 16-bit timer registers assuming

that no interrupts updates the temporary register.

C Code Example(1)

unsigned int i;

...

/* Set TCNT1 to 0x01FF*/

TCNT1 = 0x1FF;/*Read TCNT1 into i */

i = TCNT1;

16-bit Timer/Counter

Register Description

Timer/Counter1 Control

Register A TCCR1A

COM1A1:0: Compare Output Mode for Channel ACOM1B1:0: Compare Output Mode for Channel B

FOC1A: Force Output Compare for Channel AFOC1B: Force Output Compare for Channel B

WGM11:0: Waveform Generation Mode


45/64

Timer/Counter1 Control

Register B TCCR1B

ICNC1: Input Capture Noise Canceler

ICES1: Input Capture Edge Select

WGM13:2: Waveform Generation ModeCS12:0: Clock Select


Register TIMSK

TICIE1: Timer/Counter1, Input Capture Interrupt EnableOCIE1A: Timer/Counter1, Output Compare A Match Interrupt Enable

OCIE1B: Timer/Counter1, Output Compare B Match Interrupt EnableTOIE1: Timer/Counter1, Overflow Interrupt Enable


46/64

8-bit Timer/Counter2Timer/Counter2 is a general purpose, single channel, 8-bit Timer/Counter module .

8-bit Timer/Counter

Register DescriptionTimer/Counter Control

Register TCCR2

FOC2: Force Output Compare

WGM21:0: Waveform Generation ModeCOM21:0: Compare Match Output Mode

CS22:0: Clock Select


Register TIMSK

OCIE2: Timer/Counter2 Output Compare Match Interrupt Enable

TOIE2: Timer/Counter2 Overflow Interrupt Enable


47/64

Analog to Digital

Converter

ADC Multiplexer Selection

Register ADMUX

REFS1:0: Reference Selection Bits

ADLAR: ADC Left Adjust Result

MUX4:0: Analog Channel and Gain Selection Bits

ADC Control and Status

Register A ADCSRA

ADEN: ADC Enable

ADSC: ADC Start Conversion

ADATE: ADC Auto Trigger EnableADIF: ADC Interrupt Flag

ADIE: ADC Interrupt Enable

ADPS2:0: ADC Prescaler Select Bits

The ADC Data Register ADCL and ADCH


48/64

Some codes with ATmega16

Code for Line Follower using 2 Sensors and 2 DC motors

#define F_CPU 12000000UL //set your clock speed#include

int move_forward= 0b10111000;

int move_left= 0b00111000;int move_right= 0b10110000;

int left_sensor_on= 0b10000000;

int left_sensor_off= 0b00000000;int right_sensor_on= 0b00000001;

int right_sensor_off= 0b00000000;

int stop = 0b00110000;

int main (void)

{

DDRD = 0xFF; //Output port connected to motors

DDRA = 0x00; //Input port connected to sensors

int left_sensor = 0;int right_sensor = 0;

while(1) //create an infinite loop{

PORTD |=(1


49/64

PORTD |=(1


50/64

int center_rotate_right= 0b10110100;

int move_back=0b01110100;

int left_sensor_on= 0b10000000;int left_sensor_off= 0b00000000;

int right_sensor_on= 0b00000001;

int right_sensor_off= 0b00000000;int stop = 0b00110000;

int main(void){

DDRD=0xFF; //Output port connected to motors

DDRA=0x00; //Input port connected to sensors

int left_sensor=0;int right_sensor=0;

while(1)

{PORTD|=(1


51/64

if(( left_sensor==left_sensor_on) & (right_sensor==right_sensor_on))

{PORTD = move_forward;

left_sensor = 0;

right_sensor = 0;}

}

}

Code for 7-segment display

#define F_CPU 12000000UL

#include

#include#include

#includevoid main()

{

DDRA=0x00;DDRB=0x00;

DDRC=0xFF;

while(1)

{if(bit_is_set(PINA,0))

PORTC = 0b00111111;else if(bit_is_set(PINA,1))

PORTC = 0b00000110;

else if(bit_is_set(PINA,2))

PORTC = 0b01011011;else if(bit_is_set(PINA,3))

PORTC = 0b01001111;

else if(bit_is_set(PINA,4))PORTC = 0b01100110;


PORTC = 0b01101101;

else if(bit_is_set(PINA,6))PORTC = 0b01111101;


PORTC = 0b000000111;else if(bit_is_set(PINB,0))

PORTC = 0b01111111;

else if(bit_is_set(PINB,1))PORTC = 0b01101111;


52/64

}

}

Code for generation of PWM wave

#define F_CPU 12000000UL#include

#include

#include#include

void main()

{ DDRB=0x00;PORTB=oxFF;

TCCR0=0b01110101;

TIMSK=0x02;

while(1)

{for(int i=0;i=0;j--){

OCR0=j;

_delay_ms(250);_delay_ms(250);

}

}

}

Code for Timers in Compare and Overflow Mode

Overflow Mode


#include

#include#include

#include

int count=0;

ISR(TIMER0_OVF_vect){


53/64

count++;

if(count==4)

{PORTC=~PORTC;

count=0;

}}

int main(){DDRC=0xFF;

DDRA=0xFF;

PORTA=0x00;

PORTC=0x00;

TCNT0=0x00;

TCCR0=0x05;

TIMSK=0x01;sei();

while(1){

}

}

Compare Mode


#include#include

#include

#include

ISR(TIMER0_COMP_vect)

{count++;

if(count==4)

{

PORTC=~PORTC;count=0;

}

}

int main()

{DDRC=0xFF;DDRA=0xFF;

PORTA=0x00;

PORTC=0x00;


54/64

TCNT0=0x00;

OCR0=0xFF;

TCCR0=0x15;TIMSK=0x02;

sei();

while(1){

}

}

Code for Timer in Overflow mode


#include

#include

#include

#include

ISR(TIMER0_OVF_vect){

_delay_ms(250);

PORTC=0b10000000;}

}

int main()

{DDRC=0xFF;

PORTC=0x00;

TCNT0=0x00;

TCCR0=0x03; //prescalar set to 64

TIMSK=0x01;sei();

while(1)

{_delay_ms(250);

PORTC=0b00000001;

}

}


55/64

Code for External Interrupts in Overflow Mode

#define F_CPU 12000000UL#define time 0x00

#include

#include#include

#include

ISR(int0)

{

time=0x80;

}

ISR(int0)

{

time=0x40;}

int main()

{

DDRA=0xFF;PORTA=0x00;

TCNT0=time;

TCCR0=0x03;

TIMSK=0x01;MCUCR=0x0E;

sei();

while(1)

{_delay_ms(250);PORTA=0xFF:

}

}

Code for ADC

#include#include

int call_ADC(){

while(ADCSRA & 00010000) // waiting till adif flag is set

{return(ADC); // ADC=(vin/vout)*1024


56/64

}

}

void main()

{

DDRA=0x00;PORTA=0x01;

ADMUX=ob00000001 //read analog frm channel 0ADCSRA=0b11001111; // prescaler=128 and ADIE is set

int adc=call_ADC();

if(adc>0x000&&adc


57/64

IMAGE PROCESSING

Image processing involves changing the nature of an image in order to either

1. improve its pictorial information for human interpretation,

2. render it more suitable for autonomous machine perception.

3. Enhancing the edges of an image.

Some Common Formats JPEG

BMP GIF

PNG

TIFF

SamplingSampling refers to the process of digitizing a continuous function. Nyquist criterion can

be stated as the sampling theorem, which says, in effect, that a continuous function can be

reconstructed from its samples provided that the sampling frequency is at least twice the

maximum frequency in the function.

Fs > 2Fmax

Acquisition

of Image

Image

Processor

Image

Analysis

Machine vision


58/64

QuantizationQuantization refers to the number of available gray values. Again, the more values, the

better the image will appear; the fewer values will result in a less natural looking image.

Allied to quantization is thresholding, where an image is turned into black and white by

the application of a simple rule.

Functions in MATLAB for Image Processing1. imread()- Read image from graphics file. A = imread(filename,fmt) reads a

greyscale or color image from the file specified by the string filename, where the

string fmt specifies the format of the file. If the file is not in the current directory

or in a directory in the MATLAB path, specify the full pathname of the location

on your system. imread returns the image data in the array A.

2. imshow()- Display image. imshow(I) displays the grayscale image I.

imshow(RGB) displays the truecolor image RGB. imshow(BW) displays the

binary image BW. imshow(I/4) or (I*4) or (I+4) or (I-4) is used to vary the

grayscale of an image.

3. rgb2gray()- Convert an RGB image or colormap to grayscale. I =

rgb2gray(RGB) converts the truecolor image RGB to the grayscale intensity

image I.

4. imfinfo()- information about graphics file. info = imfinfo(filename,fmt) returns a

structure, info, whose fields contain information about an image in a graphics file.

5. imwrite()- Write image to graphics file. imwrite(A,filename,fmt) writes the

image A to the file specified by filename in the format specified by fmt.

6. imhist()- Display histogram of image data. imhist(I) displays a histogram for the

intensity image I above a grayscale colorbar.

7. histeq()- Enhance contrast using histogram equalization. histeq enhances the

contrast of images by transforming the values in an intensity image, or the values

in the colormap of an indexed image, so that the histogram of the output image

approximately matches a specified histogram.

8. imadjust()- Adjust image intensity values or colormap. J = imadjust(I,[low_in;

high_in],[low_out; high_out],gamma) maps the values in intensity image I to new


59/64

values in J, where gamma specifies the shape of the curve describing the

relationship between the values in I and J. If gamma is less than 1, the mapping is

weighted toward higher (brighter) output values. If gamma is greater than 1, the

mapping is weighted toward lower (darker) output values. If you omit the

argument, gamma defaults to 1 (linear mapping).

9. img(i,j)- This is used to access the (i,j)th pixel of image img.

10. filter2()-Two-dimensional digital filtering = filter2(h,X,shape) returns the part of

Y specified by the shape parameter. shape is a string with one of these values:

'full' Returns the full two-dimensional correlation. In this case, Y is larger than X.

'same'(default) Returns the central part of the correlation. In this case, Y is the

same size as X. 'valid' Returns only those parts of the correlation that are

computed without zero-padded edges. In this case, Y is smaller than X.

11. medfilt2()- Perform two-dimensional median filtering. B = medfilt2(A) performs

median filtering of the matrix A using the default 3-by-3 neighborhood.

12. imerode()- Erode image. IM2 = imerode(IM,SE) erodes the grayscale, binary, or

packed binary image IM, returning the eroded image IM2. The argument SE is a

structuring element object or array of structuring element objects returned by the

strel function.

13. imdilate()- Dilate image. IM2 = imdilate(IM,SE) dilates the grayscale, binary, or

packed binary image IM, returning the dilated image, IM2. The argument SE is a

structuring element object, or array of structuring element objects, returned by the

strel function.

14. strel()- Create morphological structuring element. E = strel(shape,parameters)

creates a structuring element, SE, of the type specified by shape. Shapes can be:

diamond, disk, line, octagon, etc.

15. imopen()- Open an image. IM2 = imopen(IM,SE) performs morphological

opening on the grayscale or binary image IM with the structuring element SE. The

argument SE must be a single structuring element object, as opposed to an array

of objects.

16. imclose()- Close an image. IM2 = imclose(IM,SE) performs morphological

closing on the grayscale or binary image IM, returning the closed image, IM2.


60/64

17. imsubtract()- Subtract one image from another, or subtract a constant from an

image. Z = imsubtract(X,Y) subtracts each element in array Y from the

corresponding element in array X and returns the difference in the corresponding

element of the output array Z.

18. edge()- Find edges in an intensity image. BW = edge(I,'sobel) takes an intensity

image I as its input, and returns a binary image BW of the same size as I, with 1's

where the function finds edges in I and 0's elsewhere.

19. bwlabel()- Label connected components in a binary image. L = bwlabel(BW,n)

returns a matrix L, of the same size as BW, containing labels for the connected

objects in BW. n can have a value of either 4 or 8, where 4 specifies 4-connected

objects and 8 specifies 8-connected objects; if the argument is omitted, it defaults

to 8.

20. guide()- Start the GUI Layout Editor. guide('filename.fig') opens the FIG-file

named filename.fig. You can specify the path to a file not on your MATLAB

path.

Some codes for Image Processing in MATLAB

Code for finding the compression ratioK=imfinfo('F:\ROBOSAPIENS\Image database\saturn.png');Imgbytes=K.Height*K.Width*K.BitDepth/8;

Compbytes=K.FileSize;

Ratio=Imgbytes/Compbytes;

Code for detecting lines in an imagea=imread('F:\ROBOSAPIENS\Image database\saturn.png');img2=im2bw(a);

i=edge(double(img2),'sobel',[]);

imshow(i);

Code for acquiring a videovid=videoinput('winvideo',1);triggerconfig(vid,'manual');

set(vid,'FramesPerTrigger',1 );

set(vid,'TriggerRepeat', Inf);

start(vid);


61/64

for i=1:1:5

trigger(vid);

im= getdata(vid,1);figure,imshow(im);

end

stop(vid),delete(vid),clear vid;

Code for finding the number of balls in an imageI=imread(ball.jpg);im=rgb2gray(I);

level= graythresh(im);

ib=im2bw(im,level);[labeled,numObjects]=bwlabel(ib,8);

x=regionprops(labeled,'basic');

k=0;

for j=1:20

if x(j).Area>2500k=k+1;

endend

Code for finding the location of objectvid=videoinput('winvideo',1);

im=getsnapshot(vid);

for i=1:5trigger(vid);

im= getsnapshot(vid);

figure,imshow(im);s=size(im);

level= graythresh(im);

ib=im2bw(im,level);[labeled,numObjects]=bwlabel(ib,8);

x=regionprops(labeled,'basic');

maxar=max([x.Area]);v=find([x.Area]==maxar);

centroid=x(v).Centroid;

if(centroid(1)s(2)/2)disp('second');

end

if (centroid(1)s(2)/2)disp('fourth');


62/64

end

if(centroid(1)>s(1)/2 && centroid(2)>s(2)/2)

disp('first');end

end

Code for Erosion and Dilation of an imagea=imread('F:\ROBOSAPIENS\Image database\saturn.png');

img=rgb2gray(a);img2=im2bw(img,0.5);

B=strel('diamond',5);

img3=imerode(img2,B);imshow(img3),figure;

img4=imdilate(img2,B);

imshow(img4),figure;

Code for counting Frames per Secondtic;

vid = videoinput('winvideo');

k=0;

while(k


63/64

PARALLEL PORT

A parallel port has-

8 Output pins [D0 to D7]

5 Status pins [S4 to S7 and S3]

4 Control pins [C0 to C3]

8 ground pins [18 to 25]

Code for parallel port data transfer using MATLABparport = digitalio('parallel','LPT1'); % define a parallel port

hwlines = addline(parport,0:7,'out'); % define 8 output lines on parallel port

bvdata = [1 1 1 1 1 1 1 1]; % Parallel port sequence for clockwise rotation

bvdata0 = [1 1 0 0 0 0 0 0]; % parallel port sequence for stopping the motorputvalue(bvdata);


64/64

--------------------------------X------------------------------------X-----------------------------------

Date post:	07-Apr-2018
Category:	Documents
Upload:	calvinnh
View:	219 times
Download:	1 times

Robo Report for Robosapiens

Documents