Target detection using
In this project we are
targeting Army based simulation. Army need time to time practice on
missiles. How to target aeroplanes. Its tough to utilize animation
at the war time. If army will waste money on animation then its
quite tough for any army to give regular training to army persons.
To solve this problem army made simulation hardware. In this project
we will make hardware it will help to target any aeroplane perfectly
and without error. It will also help to give wireless feedback. We
RF technology at 315 MHz
for wirelss feedback. We are using Rf circuit used by our seniors
in RF robot circuit. Our main problem will be to work sensors in
We will use infrared
transmitter and receiver for this purpose. Infrared sensor available
in the market we will use. In this circuit as we will get the signal
from the sensors.
We will use
microcontroller for giving pulses to laser at particular frequency.
We are using particular frequency to detect pulses and to immune
sensors from sunlight.
We will use 12Mhz
crystal to provide Clock to microcontroller.
There will IC 7805 as a
voltage regulator. And two 1000µf and 470µf as a filtering
How to control sensors
What is a voltage divider?
You are going to find
out but don't be in too much of a hurry. Work through the Chapter
and allow the explanation to develop.
The diagram below
shows a light dependent resistor, or LDR,
together with its circuit symbol:
part of the LDR is a wavy track of cadmium sulphide. Light energy
triggers the release of extra charge carriers in this material, so
that its resistance falls as the level of illumination increases.
sensor uses an LDR as part of a voltage divider.
The essential circuit
of a voltage divider, also called a potential divider,
What happens if one
of the resistors in the voltage divider is replaced by an LDR? In
the circuit below, Rtop is a 10 resistor,
and an LDR is used as Rbottom :
Suppose the LDR has a
resistance of 500 ,
in bright light, and 200 in
the shade (these values are reasonable).
When the LDR is in
the light, Vout will be:
In the shade, Vout
In other words, this
circuit gives a LOW voltage when the LDR is in the light, and a HIGH
voltage when the LDR is in the shade. The voltage divider circuit
gives an output voltage which changes with illumination.
A sensor subsystem
which functions like this could be thought of as a 'dark
sensor' and could be used to control lighting circuits
which are switched on automatically in the evening.
Perhaps this does not
seem terribly exciting, but almost every sensor circuit you can
think of uses a voltage divider. There's just no other way to make
sensor subsystems work.
Here is the voltage
divider built with the LDR in place of Rtop :
temperature-sensitive resistor is called a thermistor.
There are several different types:
The resistance of
most common types of thermistor decreases as the
temperature rises. They are called negative temperature
coefficient, or ntc, thermistors. Note the
-t° next to the circuit symbol. A typical ntc thermistor is made
using semiconductor metal oxide materials. (Semiconductors have
resistance properties midway between those of conductors and
insulators.) As the temperature rises, more charge carriers become
available and the resistance falls.
Although less often
used, it is possible to manufacture positive temperature
coefficient, or ptc, thermistors. These
are made of different materials and show an increase in resistance
How could you make a
sensor circuit for use in a fire alarm? You want a circuit which
will deliver a HIGH voltage when hot conditions are detected. You
need a voltage divider with the ntc thermistor in the Rtop
How could you make a
sensor circuit to detect temperatures less than 4°C to warn
motorists that there may be ice on the road? You want a circuit
which will give a HIGH voltage in cold conditions. You need a
voltage divider with the thermistor in place of Rbottom
This last application
raises an important question: How do you know what value of Vout
you are going to get at 4°C?
Key point: The
biggest change in Vout from a voltage divider is obtained when Rtop
and Rbottom are equal in value
Diode PIN BPW34
LM358 IC op amp
module 315 Mhz
base 40 pin
7805 voltage regulator
diode in 4001
10 µf 15v
copper clad board
To control room light intensity acc. To manpower
To controlling parking light intensity acct. to no of cars
To change the motor speed according to increasing material in
Figure 6 - Schem WELCOME TO THE
WORLD OF THE MICROCONTROLLERS.
Look around. Notice the smart “intelligent” systems? Be it the T.V,
washing machines, video games, telephones, automobiles, aero planes,
power systems, or any application having a LED or a LCD as a user
interface, the control is likely to be in the hands of a micro
Measure and control, that’s where the micro controller is at its
Micro controllers are here to stay. Going by the current trend, it
is obvious that micro controllers will be playing bigger and bigger
roles in the different activities of our lives.
These embedded chips are very small, but are designed to replace
components much bigger and bulky In size. They process information
very intelligently and efficiently. They sense the environment
around them. The signals they gather are tuned into digital data
that streams through tributaries of circuit lines at the speed of
light. Inside the microprocessor collates and calculators. The
software has middling intelligence. Then in a split second, the
processed streams are shoved out.
What is the primary
difference between a microprocessor and a micro controller?
Unlike the microprocessor, the micro controller can be considered
to be a true “Computer on a chip”.
In addition to the various features like the ALU, PC, SP and
registers found on a microprocessor, the micro controller also
incorporates features like the ROM, RAM, Ports, timers, clock
circuits, counters, reset functions etc.
While the microprocessor is more a general-purpose device, used for
read, write and calculations on data, the micro controller, in
addition to the above functions also controls the environment.
8051 micro controller
The 8051 developed and launched in the early 80`s, is one of the
most popular micro controller in use today. It has a reasonably
large amount of built in ROM and RAM. In addition it has the ability
to access external memory.
The generic term `8x51` is used to define the device. The value of x
defining the kind of ROM, i.e. x=0, indicates none, x=3, indicates
mask ROM, x=7, indicates EPROM and x=9 indicates EEPROM or Flash.
A note on ROM
The early 8051, namely the 8031 was designed without any ROM.
This device could run only with external memory connected to it.
Subsequent developments lead to the development of the PROM or the
programmable ROM. This type had the disadvantage of being highly
The next in line, was the EPROM or Erasable Programmable ROM. These
devices used ultraviolet light erasable memory cells. Thus a program
could be loaded, tested and erased using ultra violet rays. A new
program could then be loaded again.
An improved EPROM was the EEPROM or the electrically erasable PROM.
This does not require ultra violet rays, and memory can be cleared
using circuits within the chip itself.
Finally there is the FLASH, which is an improvement over the EEPROM.
While the terms EEPROM and flash are sometimes used interchangeably,
the difference lies in the fact that flash erases the complete
memory at one stroke, and not act on the individual cells. This
results in reducing the time for erasure.
microcontrollers in market.
- PIC One
of the famous microcontrollers used in the industries. It is based
on RISC Architecture which makes the microcontroller process
faster than other microcontroller.
- INTEL These
are the first to manufacture microcontrollers. These are not as
sophisticated other microcontrollers but still the easiest one to
Atmel’s AVR microcontrollers are one of the most powerful in the
embedded industry. This is the only microcontroller having 1kb of
ram even the entry stage. But it is unfortunate that in India we
are unable to find this kind of microcontroller.
Intel 8051 is CISC
architecture which is easy to program in assembly language and also
has a good support for High level languages.
The memory of the
microcontroller can be extended up to 64k.
This microcontroller is one
of the easiest microcontrollers to learn.
The 8051 microcontroller is
in the field for more than 20 years. There are lots of books and
study materials are readily available for 8051.
The best thing done by Intel
is to give the designs of the 8051 microcontroller to everyone. So
it is not the fact that Intel is the only manufacture for the 8051
there more than 20 manufactures, with each of minimum 20 models.
Literally there are hundreds of models of 8051 microcontroller
available in market to choose. Some of the major manufactures of
8051 derivatives has more number of features than in any
microcontroller. The costs of the Philips microcontrollers are
higher than the Atmel’s which makes us to choose Atmel more often
Dallas has made
many revolutions in the semiconductor market. Dallas’s 8051
derivative is the fastest one in the market. It works 3 times as
fast as a 8051 can process. But we are unable to get more in India.
were the one to master the flash devices. They are the cheapest
microcontroller available in the market. Atmel’s even introduced a
20pin variant of 8051 named 2051. The Atmel’s 8051 derivatives can
be got in India less than 70 rupees. There are lots of cheap
programmers available in India for Atmel. So it is always good for
students to stick with 8051 when you learn a new microcontroller.
base 20 pin
Crystal 12 Mhz
compiler or UMPS for programming