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Remote System Monitoring and Controlling via Web based Mobile or Desktop Application

Ranjan — Sun, 29 Jan 2012 09:41:22 +0000

Introduction

The idea of remote system monitoring and controlling application is to do some of the actions like ex: Shutdown, Reboot, Hibernate of the users systems remotely. The user can also make use of this application to query additional details of the systems.

Consider a scenario where you have a set of systems (Computers) and you want to control them from your mobile or any other desktop anywhere from the world. So this started as initial requirement of how we can implement the same to control numerous systems remotely.

Consider another scenario of how you can retrieve the information of a particular system remotely from your handheld devices or through desktops. By retrieving information, one may be interested in knowing the following

Machine Name
CPU information
Username
Domain Name
OS Version

Software Requirements Specification

Aim: The aim of this project is to provide a facility for the end user to remotely control their systems through desktop or mobile based web application.
Purpose: The purpose of this project is to implement a proof or concept of the same. And to show how easily it can be done with .NET technology
Scope: The scope of this project is very limited to controlling the system with few actions like Shutdown, Reboot, Hibernate, Logoff, Force close all applications etc. The user registration is done only at the client application and the it should be always running in-order to control the system remotely.
User Characteristics: The Following things are taken into consideration with this software development
1. Users can have multiple systems for controlling. There is absolutely no limit in the number of systems being controlled by the users.
2. The user can either control her/his systems through mobile or desktop based web application.
3. Each user can control his/her system only and don’t have access to control others systems.
4. Right now there is only one type of user of this system i.e. the System Administrators who will be using this system to control or fetch additional information of the system on their own interest.

Software and Hardware Requirement

Software Requirements:

Operating system: Microsoft Windows XP / Win 7 / Vista
.NET framework 4.0
SQL Server 2008

Hardware Requirements:

Processor Pentium 4
RAM- 256Mb
HDD-10GB

Technologies Used

Visual Studio.NET

The Client Application is developed with .NET C# Winform technology
The Server side web application is developed with ASP.NET MVC3 technology.

Internet based / Cloud based Microsoft SQL Server 2008

This software is designed with Software as a Service model with a common single cloud database which stores all the users and their system information.

How does the software functions?

Client Application:

When you run the client application for the first time, you will have to register yourself with the username and password. The same has to be provided as log on information which will authenticate the user in client and server applications.

Once authenticated, the user has to click on the Start button for continuous monitoring of the system behind the scene. The system registers by itself by putting an entry in database (this happens only for the first usage of the client app) so that the user can control that particular machine. When the user closes the client application, the entry in the database for that system will be deactivated. For subsequent usable of the client application, the system will be activated for monitoring and controlling.

Server Application:

It is a web based application, on requesting the user will be authenticated. The use has to provide the same username and password he/she has provided at the time of user registration in client app.

On successful authentication, the list of active systems will be displayed in a screen. The user can select one and perform the actions like Shutdown, Reboot etc.

Database Entity Relationship Design Diagram

M-TICKET – Mobile Booking

chitra — Wed, 24 Aug 2011 11:09:00 +0000

Chapter 1: INTRODUCTION

Nowadays SMS or Short Messaging Service is a major communication alternative. Also, in this modern world all the facilities should be available at our fingertips whenever required, wherever we are. So we thought of developing the “SMS based movie ticket reservation”. The main purpose of our project named “M-TICKET – Mobile Booking” is to make the ticket reservation simple and easy.

In the counter based movie ticket reservation, the user has to go to the counter and stand in a queue to reserve the ticket which is time consuming. Also, in the Online reservation the user should have the internet facility. Compared with these systems of ticket reservations, our system makes the reservation easy and quick.

In this application, the user can use his cell phone to send SMS to reserve the movie tickets. Also, he can get the movie updates from time to time through his Cell Phone in the form of SMS.

We try to implement this concept in small way using SMS technology. Here we show how to access the movie information that is stored in the database and reserve the ticket just by sending an SMS from your cell phone to SMS server and get back the required information on your Cell Phone.

Chapter 2: SOFTWARE REQUIREMENTS SPECIFICATION

2.1 Aim:

The aim of our project named “M-TICKET – Mobile Booking” is to develop a software which helps the user to reserve movie tickets just by sending an SMS. To access this software, the user need not load any application to his cell phone or he need not have internet facility. He needs to just send an SMS in a prescribed format to reserve the ticket.

2.2 Purpose:

The purpose of our project is to make ticket reservation simple and easy and to provide a cheaper way of reserving the ticket just by sending an SMS.

2.3 Scope:

This project will provide a simple way to reserve tickets. A user can reserve the tickets in two ways- SMS based reservation and counter based reservation. For the SMS based reservation the user has the facilities to register his mobile phone, reserve the tickets, request for movie updates, cancel the tickets and unregister his mobile number. The user will get an appropriate reply through SMS to his cell phone. The user can also come to the counter to reserve the tickets. The payment can be done either through credit card or in the counter.

2.4 User Characteristics:

A customer will be having the certain requirements that must be provided by the system. Hence at the initial stage of the software development, a requirement analysis is performed to identify the needs of the customer. Our software is movie ticket reservation software which can be used in any theatre. To make it applicable in any of the theatres, we have taken into consideration the following requirements:

Theatre can have any number of screens.
Each screen can have any number of classes.
The price of the ticket is based on the class.
Each class can have any number of rows.
Each row can have any number of seats.
Each screen can have certain number of shows per day.
The screen can have different movies in different shows.
Two different screens can have different movies running simultaneously.

There are two types of users of the system. One is the customer and the other is the administrator

The Customer should be able to

- Register with his username and credit card number (optional)
- Reserve the ticket
- Make payment either through credit card or through the counter
- Cancel some or all the reserved tickets
- Get the movie updates of the theatre
- Unregister

The Administrator should be able to

- Register himself by giving his details along with the user name and password
- Login into the system
- Update his information
- Change password
- View seat status
- Edit the screen, class, price, movie, seat, show time information etc.
- Perform reservation, cancellation, payment operations in the counter
- Delete the old records

The reservation can be done only for 2 days – today and tomorrow. After reserving the ticket, the payment must be done and the ticket must be collected before 45 minutes of the show. Otherwise the reserved tickets will be cancelled.

There are 2 modes of reservation:

Counter based reservation
SMS based reservation

In the counter based reservation, seats are reserved manually by the Administrator. The customer should come to the counter, and specify the movie, date of show, time of show, class and the number of seats required. Then the Admin will check the availability of seats. If the seats are available, then the reservation will be done and the reservation code will be given to the customer. The customer can also cancel some or all the reserved seats.

In the SMS based system, all the operations are done automatically by the system. The customer should first register himself through the SMS. A registered customer can reserve the seats, cancel the reserved seats, request for the movie updates of the theatre and unregister all by sending the SMS in the specified format.

Two payment options are available to the registered customer:

Credit card based payment
Counter payment
When the reservation code is entered, the system should automatically show the amount of money needs to be paid.

2.5 Feasibility Study:

The process of analyzing the requirements of the system should always be preceded by the feasibility study of the system to be developed. It involves knowing what the system must achieve and whether these requirements can be satisfied with the current software and hardware technologies available.

The SMS based reservation software should provide the following basic features:

It must enable designing the user friendly front end.
It must provide means to connect to the database where the data is stored.
It should provide the means to transfer the messages between the cell phone and the computer system.
It should provide the means to process the message.

Considering all these needs, we can use Visual Basic.NET Framework to develop the front end and to process the message, MS-SQL Server to create the database, ADO objects to database connectivity and ATtention (AT) commands to transfer the messages between the cell phone and the computer.

Feasibility of the system:

The feature required in the software	Technology used to provide the feature
1. User friendly front end	VisualBasic .NET Framework
2. Database	MS-SQL Server
3. Database connectivity	ADO.NET objects
4. Message transfer between cell phone and computer	ATtention (AT) commands

2.6 Software Requirements:

Operating system: Microsoft Windows XP
Microsoft Visual Studio 2005
SQL Server 2005

2.7 Hardware requirements:

Processor Pentium 4
RAM- 256Mb
HDD-10GB
USB cable
Cell Phone

We will try to implement our project in a small way using SMS technology. Here we will show how to access the movie information stored in the database and reserve the ticket just by sending an SMS from your cell phone to SMS server and get back the required information on your Cell Phone. This application is implemented using VB.NET (Visual Basic .NET) as front end, MS-SQL Server as backend, ADO.NET for connectivity and the AT (ATtention) commands are used to transfer the messages from the cell phone to the computer through Comport.

Line Following Robot

Ranjith — Fri, 01 Jul 2011 07:08:41 +0000

Project By: HBeonLabs, Greater Noida, India
Project cost: Rs. 4000/-
How to buy: Just send a mail to info@electrofriends.com

This Project Line Following Autonomous Robot is based on 8 bit Microcontroller. This Robot follows the black line which is drawn over the white surface or it follows the white line which is drawn over the black surface. The infrared sensors are used to sense the line. When the infrared signal falls on the white surface, it gets reflected and if it falls on the black surface, it is not reflected this principle is used to scan the Lines for the Robot. All the above systems are controlled by the Microcontroller. Microcontroller gets the signals from the infrared sensors and it drives the motors according to the sensor inputs. Two stepper motors are used to drive the robot.

THEORY OF OPERATION-: How to sense a black line The sensors used for the project are Reflective Object Sensors, 0PB710F that are already ready in the Electronic Lab. The single sensor consists of an infrared emitting diode and a NPN Darlington phototransistor. When a light emitted from the diode is reflected off an object and back into the phototransistor, output current is produced, depending on the amount of infrared light, which triggers the base current of the phototransistor. In my case, the amount of light reflected off a black line is much less than that of a white background, so we can detect the black line somehow by measuring the current. (This current is converted to voltage.)

ii) How to control a DC motor
Instead of applying a constant voltage across a DC motor, we repeat switching on and off the motor with a fixed voltage (Vcc) applied to the motor. This is done by sending a train of PWM (Pulse Width Modulation) pulses to a power MOSFET in order to turn it on and off. Then, the motor sees the average voltage while it depends on duty cycle of PWM pulses. The speed of rotation is proportion to this average voltage.
By PWM method, it’s easier to control the DC motor than by directly controlling the voltage across it. All we have to do is to modulate pulse width, in ord

BLOCK DIAGRAM-:

Project By: HBeonLabs, Greater Noida, India
Project cost: Rs. 4000/-
How to buy: Just send a mail to info@electrofriends.com

Design and Verification of a PCI Based System using SystemC

Ranjith — Sun, 06 Feb 2011 08:04:16 +0000

Study about PCI Bus protocol before reading this project

1.1. System Design Introduction:
The present design is of a PCI based system consisting of three Masters and six Slaves. The masters communicate with the slaves using the PCI bus. The transaction is governed by the standard PCI bus transaction protocol. Whenever a master needs to communicate with any of the slaves through the PCI bus it requests for the control of the bus to the arbiter. The arbiter grants the master control of the bus depending on the availability of the bus and also on the requesting master’s priority. Once the master is granted control of the bus it starts the transaction by keeping the address of the target slave along with the transaction command. The address thus kept is read by all the slaves. This address is decoded by each of them individually. If the address belongs to them, that particular slave acknowledges the call. This is the address phase. The address phase lasts for just one clock cycle. Once the address phase is finished the data phase begins. If none of the slaves acknowledge the masters call then the master aborts the transaction.

The design verification is done using the testbench. The testbench is connected to the design using channels. The testbench tells the master what transaction is to be carried out and also inspects the data sent and received at the slave end. The block diagram is as given below.

General system block diagram

1.2. System

This section describes the working of the present design in brief. The block diagram of the system is as shown in below fig.

The DUT consists of Master module, Slave module, Arbiter module, Channel declaration and a top file which connects all the instances. Just one module of the master is defined and three objects are instantiated in top file. The same is being done with the slave module, just one slave module is being described and six objects are being instantiated from it in the top file.

The interconnections of all the modules are shown below. Each of the blocks is as described below.

General block diagram of the system

1.2.1 Master :
In the fig5.2 Master 1, Master 2 and Master 3 are all instances of the main module Master. The master receives packets of information from the test bench. This packet contains information regarding address of the destination, command definition and data. It also tells which master is to carry out the transaction. Once the master receives and decodes this packet it begins the required transaction.

Whenever a master has to undertake any transaction it first requests the arbiter for permission to take over the bus. Once the arbiter has granted the request, the master begins the required transaction.

The transaction begins with the master by asserting FRAME#. At the same time it keeps the address of the destination along with the transaction command definition. This is called ‘Address phase’. Once the address phase is done, the master asserts IRDY# and waits for the addressed slave to asserts DEVSEL#. If DEVSEL# is not asserted until the latency time runs out, the master ends the transaction with ‘Master abort’. If DEVSEL# is asserted the ‘Data phase’ begins. The data transaction between the master and slave takes place only when both IRDY# and TRDY# are asserted. As soon as TRDY# is asserted the master places the data on the AD lines during write transaction and during read transaction it reads the data from the bus after assertion of TRDY#. All signal assertions are done during the negative clock edge and are sampled during the positive clock edge. Care should be taken to see that the signals or data on the AD lines are stable during the positive edge of the clock pulse. The master can make the target wait for the data by deasserting the IRDY# signal.

Parity of AD, C/BE and PAR are checked regularly during each phase (data/address). During write transaction the master keeps the data on the multiplexed AD lines during one clock cycle and keep its parity during next clock cycle. During a read transaction the master checks for parity during the second clock cycle of the received data. If parity is found to be odd, it asserts the PERR# during the third clock cycle. This will result in ‘Master abort’.

In some cases the slave might be ready to carry out the present transaction that the master is requesting. During such a situation the master should end the transaction and retry after some time, but with the same address and command definition. The end of the transaction is marked by deassertion of FRAME#. The FRAME# might be deasserted after the last data has been transferred or just before the last data phase. Once all the data are transferred or received IRDY# is deasserted.

1.2.2 Slave :

In fig 5.2, Slave 1 – Slave 6 are the instances derived from the module called Slave. Each slave is assigned with a unique address that is used by the master to notify which slave it wants to interact with. The address is assigned while the object of slave is instantiated.

Before a slave undertakes nay memory or i/o based transactions its configuration space should be configured. In the present design this is done by any of the masters. Rest of the transactions are done depending on the content present in the configuration space. In our design we have implemented the configuration space using a structure. Once the slave has been configured it is ready to undertake any of the transactions.

The transaction begins when the master asserts FRAME#. During the address phase all the slaves read the address placed on the AD lines. In the same clock pulse each slave compares the read address with the content stored in the base address registers present in the configuration space. If the address belongs to any particular slave it acknowledges by asserting DEVSEL# in the next clock cycle. If the slave is ready to undertake the required transaction it asserts TRDY# along with DEVSEL#. But, if the slave is not ready to undertake the required transaction it asserts STOP# instead of TRDY# telling the master to retry the same try the same transaction after some time. Once TRDY# and IRDY# are asserted the data transfer takes place. If IRDY# is not asserted then the slave has to wait until the master asserts it. The slave has to wait until the master asserts it. The slave can also make the master wait by deasserting TRDY# and asserting it only when it is ready to receive/send data.

The memory and i/o space are implemented in the monitor. The slave extracts the address of the destination location from the address that is being sent from the maser and sends it to the monitor along with the data to be stored or retrieved.

In case of blast transaction if the slave is not able to continue with any more transaction it aborts the transaction. There are three ways a slave can abort a transaction – ‘Target Abort’, ‘Target abort with data’ and ‘Target abort without data’. In ‘Target abort’, the slave needs to abort if just asserts STOP# and at the same time deasserts DEVSEL# as well as TRDY#. In ‘Master abort without data’, as soon as STOP# is asserted only TRDY# is deasserted. DEVSEL# is deasserted only clock pulse after FRAME# is deasserted. In this case no data is transmitted one the STOP# is asserted. During ‘Target abort with data’, one data phase is allowed after STOP# is asserted. After one data phase has been completed TRDY# is deasserted. The rest of the deassertion are similar to that of target abort without data.

Parity of AD, C/BE and PAR are checked regularly during each phase (data/address). During read transaction the slave keeps the data on the multiplexed AD lines during one clock cycle and keeps its parity during next clock cycle. During a write transaction the slave checks for parity during the second clock cycle of the received data. If parity is found to be odd, it asserts the PERR# during the third clock cycle. This will result in ‘Target abort’.

1.2.3 Arbiter :

Since the PCI Bus accommodates multiple masters — any of which could request the use of the bus at any time — there must be a mechanism that allocates use of bus resources in a reasonable way and resolves conflicts among multiple masters wishing to use the bus simultaneously.

The arbiter is used to grant permission to the requesting master. When more than one master is requesting, the arbiter takes in all the requests and decides which master should be granted the permission of using the bus. The arbiter selects the master depending on its priority i.e. the requesting master with the highest priority is selected first by asserting the GNT# signal. In case of multiple requests the grant is given using ‘Round Robin’ logic. The grant is given by asserting the respective GNT(G1,G2,G3) signal. Every master is connected to the arbiter by individual REQ(R) and GNT(G) signals as seen in the fig 1.2. REQ# and GNT# are unique on a per master basis allowing the arbiter to implement a bus fairness algorithm. Arbitration in PCI is “hidden” in the sense that it does not consume clock cycles.

Wireless Data Transmission between Computers using Sequence Detector

Ranjith — Sun, 28 Mar 2010 14:00:48 +0000

ABSTRACT

Here for the purpose, we have made four distinct stages for the effective implementation .The stages are described in brief as follows. In the first stage, we are constructing the transmitter circuit that transmits data and sequence bits at infrared frequency. Now the second part is to develop receiver circuit that receives infrared signals coming out from transmitter and convert them into bits. The next stage is to compare the incoming sequence with that of receiver computer. If sequence is matched only then it will be able to catch the data sent by transmitting computer. The fourth and final stage is the make software program that gets the data and displays on computer.

INTRODUCTION

Wireless data transmission between computers is a flexible data communication system implemented as an extension to, or as an alternative for, a wired LAN within a building. It can further be extended to wireless LAN with secure data transmission. For the purpose of secure data transmission a unique code is sent before actual data bits. This unique code is known to receiver. In this project sequence detector at receiver side has been used which is set for a particular code. This sequence detector detects binary bit stream coming out from transmitter and if code of incoming bit stream is matched with the code of sequence detector than rest of bits are received in form of data at the receiving computer’s side. To further enhance the concept of security we are using Infrared waves as a channel between transmitter and receiver because security of infrared systems against eavesdropping is better than that of radio systems. The block diagram of whole system is shown below.

Block Diagram

Wireless transmission block diagram

WIRELESS LAN

Wireless LANs use electromagnetic airwaves (radio or infrared) to communicate information from one point to another without relying on any physical connection. Radio waves are often referred to as radio carriers because they simply perform the function of delivering energy to a remote receiver. The data being transmitted is superimposed on the radio carrier so that it can be accurately extracted at the receiving end. This is generally referred to as modulation of the carrier by the information being transmitted. Once data is superimposed (modulated) onto the radio carrier, the radio signal occupies more than a single frequency, since the frequency or bit rate of the modulating information adds to the carrier.

Wireless LAN architecture

Multiple radio carriers can exist in the same space at the same time without interfering with each other if the radio waves are transmitted on different radio frequencies. To extract data, a radio receiver tunes in one radio frequency while rejecting all other frequencies.

In a typical wireless LAN configuration, a transmitter/receiver (transceiver) device, called an access point, connects to the wired network from a fixed location using standard cabling. At a minimum, the access point receives, buffers, and transmits data between the wireless LAN and the wired network infrastructure. A single access point can support a small group of users and can function within a range of less than one hundred to several hundred feet. The access point (or the antenna attached to the access point) is usually mounted high but may be mounted essentially anywhere that is practical as long as the desired radio coverage is obtained.

End users access the wireless LAN through wireless-LAN adapters, which are implemented as PC cards in notebook or palmtop computers, as cards in desktop computers, or integrated within hand-held computers. Wireless LAN adapters provide an interface between the client network operating system (NOS) and the airwaves via an antenna. The nature of the wireless connection is transparent to the NOS.

Electronic Identification and Personal Information card using 8951 Microcontroller

Ranjith — Wed, 17 Mar 2010 04:55:52 +0000

Preface: – Presently there are many types of cards available such as punch cards, magnetic cards, optical cards but all are having the disadvantage of performance degradation as we use them.

Other disadvantages are: -

They can not store much information.
They can not be read from a distance.
They lose their data if placed under magnetic field or even on scratching.
There is no security to protect card data whereas in our card this is achieved with the provision of passwords.
There is no Re-Writable memory for temporary data storage such as railway reservation ticket.

The above-mentioned shortcomings are technical but there are user related problems also when one needs to handle a large number of cards at a time to obtain diverse information (Atm, Credit card, License, Voter Id. etc.). The user is highly inconvenienced as he is required to change over the cards frequently, so we have designed a card which combines information contained in a variety of cards. Since data is transferred using IR sensors so in many applications we can identify the user from a distance. We can also lock the data stored in card by using various passwords. Card can also store specific data in RAM for temporary use such as railway reservation, air bookings etc. we can also use the cards in automatic doors fitted with sensors which read the card from some distance and open the door only for authorized card holders.

BLOCK DIAGRAM

1. Card Unit: -

Block diagram of card unit

IR Sensors: - We are using here the infrared light as communication medium because of its low cost and better reception in short range communication. To make the receiver perform better it is designed to recognize the switching IR light of particular wavelength.

The wave length and switching frequency can be taken from the manufacturers data sheets

Buffer Amplifier: – The O\P of sensor does not have the current capacity to drive the microcontroller hence we use the buffer amplifier between sensor and micro controller.

Buffer Amp 2: – This section provides the current gain to signals coming from microcontroller.

Astable M.V.: – It generates the switching waveform to switch the IR LED on & off the frequency of the M.V. depends upon the sensor used.

Micro controller: – This is the part of card which stores the data in its EEPROM & also performs all the operations required for testing the incoming data & to decide the response of received data. It also controls the mode of serial communication and speed of communication.

2. PC Unit: –

Block diagram of PC Unit

For the pc unit all the blocks are same but instead of using microcontroller we use serial port of pc which follows the RS232 standard hence we use a Level Converter between port and Buffer Amp.
The first level converter converts the TTL signals in to RS232 signals & second level converter converts the RS232 signals to TTL signals. The conversion is necessary because the sensors & M.V. works on TTL logic.

3. Door unit: –

Block diagram of door unit

Here we implemented one utility of the card by opening the cabin door (in office) automatically as the authorized person come up to a certain distance from door, by reading his or her card from distance.

Now if the cards data does not match with door unit it sends the persons card number to PC & ask to open the door if operator press Y the door unit will open the gate.

To complete the door unit we require combining the following section as shown in block diagram.
Now we see that all the sections as same as we have discussed in previous blocks except that Relay & Beeper section. So we will discuss only this section. The door unit performs the two work one send data to call the specific data from card & read data from card through sensor. Now if persons card no does not match with unit it sends the pulses the beeper unit which produce the intermittent beep sound to indicate that door is not opened.

Automatic solar tracking system

Ranjith — Fri, 29 Jan 2010 18:29:44 +0000

AUTOMATIC SOLAR TRACKER starts following the SUN right from dawn, throughout the day, till evening, and starts all over again from dawn next day. On cloudy weathers, it remains still and catches the SUN again as it slips out of clouds. It does all this automatically, employs cheap and inexpensive components, and is very accurate.Let us see how it does all this.

There are three Electronic Modules to be explained. First one is the HORIZONTAL SENSOR MODULE. It employs the timer 555 in the MONOSTABLE MODE. PIN 2(Trigger Pin of 555) is hooked up with a VOLTAGE DIVIDER NETWORK(PLEASE see FIGURE 2). PIN 4(Reset) is hooked up with ANOTHER VOLTAGE DIVIDER NETWORK.

Fig 1: Block diagram of the tracker following the sun all through

Fig 2: Horizontal sensor electronic circuit

The LDR(SAY LDR A) which is always illuminated by light through FRESNEL LENS ARRAY, has Low Resistance(in presence of light resistance of LDR decreases and vice-versa). We know V(OUT)=V(IN)*[R(bottom)]/[R(bottom)+R(top)], where R stands For Resitance. So in SUNLIGHT, when LDR A’s resistance Decreases, VOLTAGE AT PIN 4 Increases. TIMER is no more RESET. PIN 2 is now lower than 1/3 rd Vcc(as the horizontal LDR 1, say LDR B does not initially receive light through its rectangular slit, so its resistance is high(Rtop=8 K ohms), consequently V(OUT) is low). This triggers the timer which gives a pulse to Decade Counter’s Clock(14) PIN and triggers it. The Decade Counter CD 4017 gives a NORMAL STEP DRIVE pulse to the Horizontal Unipolar Stepper Motor 1(coupled to the tracker unit) to rotate the tracker position so as to receive sunlight(STEP ANGLE of 2 DEGREES). This goes on till the horizontal LDR 1 is fully in SUNLIGHT(resistance low, so PIN 2’S VOLTAGE HIGH). Thus the tracker has followed the SUN Horizontally.

Fig 3: Horizontal Sensor electronic circuit

We will come to the Vertical Sensor Module, but first let us see what the DAWN LDR(SAY LDR C) does. At night the horizontal Module timer 555 remains Reset(as LDR A is in darkness so its resistance is high, thus pin 4 voltage is low, and the TRACKER points at WEST(where SUN has set). Next day when SUN rises again in the EAST, the DAWN LDR which is located at the back of the TRACKER, points at EAST. So when it receives sunlight its Resistance goes low, thus Voltage at pin 4 is high and the timer triggers the Decade Counter which in turn switches the Motor on, thus the TRACKER again moves towards the EAST. Then the TRACKER functions as previously.

Now placed with the Horizontal Sensor LDR 1 is another similar LDR 2 which receives the sunlight as and when does LDR 1. SEE FIGURE 3. So now, as LDR B(THE 1st horizontal one) receives sunlight, so does Horizontal LDR 2(SEE FIGURE 1, THESE 2 LDRs are placed together with same alignment properties and separated by an optically insulated coating(from each other).Thus when Motor 1 comes to rest, and as the second horizontal LDR (SAY LDR D),is same way coupled to the second timer’s(of Vertical Module) Reset pin as was the ALWAYS ILLUMINATED LDR A, it brings the second timer out of its Reset mode) by the previously discussed VOLTAGE RELATIONSHIP). EYE SENSOR LDR(SAY LDR E) of the tracker receives sunlight by an Anti-Reflection Coated, small Rectangular Slit, so reacts only when SUN directly points at it. The second 555’s PIN 2 is same way connected to this LDR as was the first 555’s to Horizontal LDR 1. So now that it still not receives sunlight (resistance high, so Vout low) and pin 4 is no more Reset, the second CD 4017 MAKES THE SECOND STEPPER MOTOR 2 Rotate(Coupled so as to only rotate VERTICAL SENSING BLOCK/EYE BLOCK ). This movement continues till the SUN directly points at the EYE of our TRACKER. Then the TRACKER STOPS, pointing very accurately at the SUN.FIG 2 and FIG 3 follows.

fig 4: Stepper motor control board

In figure 4 I have only shown the Horizontal Motor Control Circuit. The Vertical One uses a similar Decade Counter, NPN Transistors, Diodes(to encounter BACK EMF of Power Transistors due to Fast Switching). I chose for a Step Angle of 2 Degrees for the Unipolar Steppers. They are driven in a Normal 4 Step Sequence, first coil A is energised simultaneously with coil B ,then coil C with coil D. Thus the Motors rotate by 2 degrees each time. The Charging Interval(how long pin 3 of 555’s remains high) is almost in synchronism with the steps/second speed of the motors(here 600 steps/sec.), to avoid FALSE TRIGGERING.

NOTE:

For 555 in MONOSTABLE MODE, T=1.1*R*C.
For the FRESNEL LENS ARRAY , the standard FL 40(Focal Length=0.4 inches) Or FL 65(Focal Length=0.65 inches) FRESNEL LENSES could be used (with the Grooves facing the LDRs).
For the ANTI-REFLECTION COATING, MULTI-LAYER COATING could be used to minimize loss due to REFLECTION. By using alternating layers of a Low-Index material like SILICA and a Higher-Index material, it is possible to obtain Reflectivities as low as 0.1% at Single Wavelength.

CONCLUSION:

We Conclude with the ADVANTAGES of the TRACKER MODULE SYSTEM:

Uses SIMPLE, INEXPENSIVE ,EASY TO GET 555 timers and LDRs.
The whole System draws only 25 MicroAmperes of Current when the Motors are not rotating.(555 timer’s off-state current req. is very less).BATTERY POWER IS SAVED.
The TRACKER not only follows SUN from EAST to WEST and back to EAST in a cyclic manner(Horizontal Motor Module),but also tracks the Angular Movement of the SUN with respect to its ZENITH ANGLE to the Horizon(Vertical Motor Module and EYE).This is a VERSATILE quality for which the TRACKER could easily be used in conjunction with Solar Panels to derive maximum Solar Energy. Fast Motor Response(600 steps/sec.),no FALSE TRIGGERING, a Very ACCURATE System, it requires no Programming Devices(MICROPROCESSORS or MICROCONTROLLERS), so is NOT COMPLICATED.

10W Audio Amplifiers

Ranjith — Sat, 10 Oct 2009 10:54:32 +0000

Introduction: Amplifier device that accepts a varying input signal and produces an output signal that varies in the same way as the input but has larger amplitude. The input signal may be a current, a voltage, a mechanical motion, or any other signal; the output signal is usually of the same nature. The most common types of amplifiers are electronic and have transistors or electron tubes as their principal components. Electronic amplifiers are used in radio and television transmitters and receivers, audio and stereo systems, intercoms, and other consumer electronics devices. Amplifiers in their simplest form are built around a single transistor. In one type of single-transistor amplifier, known as a common-emitter circuit, a varying input voltage is fed to the base of the transistor, and the output appears at the transistor’s collector; the ratio of the output voltage to the input voltage is called the voltage gain. For many purposes a single transistor does not provide sufficient gain, or amplification.

In a cascade, or multistage, amplifier, the output of the first amplifying device (transistor) is fed as input to the second amplifying device, whose output is fed as input to the third, and so on until an adequate signal amplification has been achieved. In a device such as a radio receiver, several amplifiers boost a weak input signal until it is powerful enough to drive a speaker. Usually, multistage amplifiers are not made of discrete components, but are built as integrated circuits . Another less common group of electronic amplifiers use magnetic devices as their principal components. There are also many kinds of mechanical amplifiers, e.g., the power steering This audio amplifier project is a class AB audio power amplifier using a TDA2003 module power amplifier. It is easy to construct and has only a few external components. The module is designed with short circuit and thermal protection. It can drive loads as low as 1.6 ohm and is capable of delivering over 10 watts from a 16 V DC power supply.

The power supply required for is 8 – 18V DC at 1 Amp or more. Maximum output power will only be obtained with a power supply of greater than 1A at 16V DC, and using 2 ohm speakers (or 2 by 4 ohm speakers in parallel). However approximately 4W RMS can be obtained with a 12V DC, 1A supply into a 4 ohm load. The power supply should be well filtered to reduce mains hum, the on board capacitors alone are not adequate for this purpose but are necessary to ensure stability. Extra filtering is unnecessary if operating from a battery. If two boards are used for stereo, you will need to double the size of the power supply.

Circuit Diagram

10 W Audio Amplifiers Circuit diagram

Step Taken While Preparing Circuit:

The main purpose of printed circuit is in the routing of electric currents and signals through thin copper layer that is bounded firmly to and insulating base material some times called the substrata. This base is manufactured with an integral bounded layer of thin copper foil which has to be partly etched or other wise removed to arrive at a pre-designed pattern to suite the circuit connections.

From the constructors point of view the main attraction of using PCB is its role as the mechanical support for small components. There is less need for complicated and time consuming metal work or chassis construction except perhaps in providing the [mal enclosure. Most straight forward circuit designs can be easily converted into printed wiring layout the thorough required to carry out the conversion can often highlights any possible error that would otherwise be missed in convention point to point wiring. The finished project is usually neater and truly a work of art. Through proper design of PCB can get noise immunity. The fabrication process of the printed circuit board will determine to a large extent the price and reliability of the equipment. A common target aimed at is the fabrication of small series of highly reliable professional quality PCBs with low investment cost.

There are two types of PCB:-

Single sided board
Double sided board

Single sided board: The single sided PCBs are mostly used in endearment electronics where manufacturing costs have to be kept at a minimum however in industrial electronics. Also cast factors cannot be neglected and single sided boards should be used whenever a particular circuit can be accommodated on such boards.

Double sided boards: Double sided PCBs can be made with or without plated through holes. The production of boards with plated-through holes is fairly expensive. Therefore, plated through hole boards are only chosen where the circuit complexity and density dose not leave any other choice.

Layout Design:

The layout of a PCB has to incorporate all the information on the board before one can go on to the artwork preparation. This means that a concept, which clearly defines all the details of the circuit, is a prerequisite before the actual layout can start. The detailed circuit diagram is varying important for the layout designer but the must also be familiar with the design concept and with the philosophy behind the equipment. When designing the layout one should observe the minimum size (component body length and weight). Before starting to design the layout have all the required components to hand so that an accurate assessment of space can be made care must be taken so as to allow for adequate air flow after the components have been mounted. It might be necessary to turn some components round to a different angular position so that terminals are closer to the connections of other components. The scale can be checked by positioning the components on the squad paper. If any connection crosses, then one can reroute to avoid such condition. All common or earth lines should ideally be connected to a common line routed around the perimeter of the layout this will act as the ground plane. If possibly try to route the outer supply line ground plane. If possibly try to route the other supply lines around the apposite edge of the layout or through the center. The first step is to rearrange the circuit to eliminate the crossover without altering the circuit detail in any way.

Plan the layout as if looking at the top side of the board first this should be translated in reverse later for the etching pattern. Larger areas are recommended to maintain good copper adhesive. It is important to bear in mind always that copper track width must be at least to the recommended minimum dimensions and allowance must be made for increased width where termination holes are needed from this aspect it can become little tricky to negotiate the route for connections to small transistors. One can effect the copper interconnection pattern in the under side of the board in a way described below Make the interconnections pattern looking like conventional point to point writing by routing uniform width of copper from component to component.

AT89Sxx Cheap and Simple Learning Board

Tahan Prahara — Tue, 18 Aug 2009 13:38:41 +0000

Build your own a cheap simple Microcontroller learning board S-52. The board is based on ATMEL’s new ISP chip AT89S51, AT89S52, or AT89S53. This board can be used by beginners for learning Assembly and C language programming. Single sided PCB file included.

Introduction

I have designed this leaning board to be used as a tool for learning MCS-51 Microcontrollers.

The AT89Sxx learning board features,

Designed for new ISP chips, 89S51, 89S52, and 89S53, 40-pin DIP,
In System Programmable (ISP) through the 6-pin header and a jumper, (no need external programmer),
TxD and RxD serial port for communicating with serial devices,
32 bit GPIO,
Onboard rectifier and +5V DC voltage regulator,
Single Sided PCB design.

Hardware

The board design is kept as simple as possible so that everone can make the learning board easily. The schematic shown below shows the complete hardware schematic of the AT89Sxx learning board. PORT0, PORT1, PORT2, and PORT3 are available for interfacing external devices. P3.0 and P3.1 are being used for RS232 interface.

Figure1: Complete hardware schematics: MCU, and power supply

Components:

R1 330 1/4W +/-5%

R2 10K 1/4W +/-5%

R3-10 10K 1/4W +/-5% (for pull up on P0)

C1 1000uF/16V electrolytic capacitor

C2 100uF/16V electrolytic capacitor

C3 100nF multilayer or ceramic

C4 10uF/16V electrolytic

C5,C6 33pF ceramic

D1 1N4001 / 1N4002 silicon rectifier diode

D2 LED

U1 LM7805, voltage regulator

U1 AT89S51, AT89S52 or AT89S53

X1 Crystal 1MHz – 33MHz (11.0592MHz is suitable for standard BAUD rate generator using timer1, says 9600 )

DB25 parallel port, 25pins connector

Construction

In order to make the AT89Sxx learning board, download the PCB ZIP file click on PCB ZIP FILES link given below. The file contains the single sided PCB track layout in PDF. Use the convenient file for making the PCB. Put the components as shown in the picture shown below.

How to make PCB?

You can print the PCB file. I have designed it using Express PCB (freeware)
Figure2: Component placement layout.
Then copy with copier machine on tranparant paper. If you have a laser printer, you can print it on transparant paper or glossy photo paper.
After that, pell on PCB with clothes Iron.
After 5-15 minutes I turn off the clothes iron and remove the board to let it cool down.
It needs to cool down because it is quit hot (30-40 degree Celcius)
Remove the paper form PCB. You can see how I am removing that paper. Movie file

AT89Sxx Cheap and Simple Learning Board

Code Programming

The SPI In system Programming adapter such as Cheap Loader Cable of Asim’s ISP for 89S51 89S52 can be used for program loading to the MCU. Connect the ISP adapters 6 pin connector with the 6 pin ISP header on this board. Run the ISP software on PC for sending the Intel hex file to microcontroller. Then program will start running.

Figure4: ISP cable schematics

Figure5: How to connect isp cable to board

Figure6: ISP Flash Programmer

Project by Tahan Prahara, prahara_satria@yahoo.co.id

“JavaBot” LINE FOLLOWER ROBOT from Java, Indonesia

Tahan Prahara — Tue, 18 Aug 2009 09:43:23 +0000

The line follower robot with wireless video camera.

I have designed it just for fun. First I want to know how the line sensor work. I used comparator IC using LM339, two H-bridge sensor using eight transistors, FCS9013, and four transistors, FSC 9012. For the sensor you can use LED and LDR as the light receiver. I changed the LDR sensor to IR sensor. I built this robot using only the analog comparator and IR sensor, no microcontroller. This is smart idea and very cheap approach.

You can download this PCB FILE (ExpressPCB file)

Figure 1: main layout and sensor layout.

Components:

R1, R7, R13, R14, R15, R16 – 330 1/4W +/-1%
R2, R3, R4, R5, R6, R8, R9, R10, R11, R12 – 10K 1/4W +/-1%
R17, R18, R19, R20 – 150 1/4W +/-1%
VR1, VR2 – 20K-50K
Led1, Led3 – LED(red) 3mm Led
Led2, Led4 – LED(green) 3mm Led
Optocoupler – 2 piece

Q1, Q2, Q3, Q4, Q5, Q8, Q9, Q12 – FSC 9013
Q6, Q7, Q10, Q11 – FCS 9012

U1 – LM 339
Battery 9 volt – 1 piece
Motor DVD dc 5Volt – 2 pieces
Tank toys for mechanic and wheel – 2 pieces

Figure2: JavaBot, my first line follower robot without the microcontroller.

There are two line styles, white line on the black floor and black line on the white floor.

If you use black line on the white floor, you can set the robot if the Right-Sensor is on the dark side or black line and Left-Sensor is on the floor it will go to forward (by swap polarity of the motor). If the Right-Sensor is on the floor and Left-Sensor is on the black line it will go to backward.

Figure3: Attach the wireless video camera to the JavaBot.

This project by Tahan Prahara, prahara_satria@yahoo.co.id