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 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.

Other disadvantages are: -

1. They can not store much information.
2. They can not be read from a distance.
3. They lose their data if placed under magnetic field or even on scratching.
4. There is no security to protect card data whereas in our card this is achieved with the provision of passwords.
5. 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.

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:

1. For 555 in MONOSTABLE MODE, T=1.1*R*C.
2. 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).
3. 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:

1. Uses SIMPLE, INEXPENSIVE ,EASY TO GET 555 timers and LDRs.
2. 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.
3. 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.

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:-

1. Single sided board
2. 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.

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?

1. You can print the PCB file. I have designed it using Express PCB (freeware)
   

   Figure2: Component placement layout.

2. 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.
   

3. After that, pell on PCB with clothes Iron.
   

4. 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)
5. 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

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

The VMSS (Vehicle Monitoring and Security System) is a GPS based vehicle tracking system that is used for security applications as well. The project uses two main underlying concepts. These are GPS (Global Positioning System) and GSM (Global System for Mobile Communication). The main application of this system in this context is tracking the vehicle to which the GPS is connected, giving the information about its position whenever required and for the security of each person travelling by the vehicle. This is done with the help of the GPS satellite and the GPS module attached to the vehicle which needs to be tracked. The GPS antenna present in the GPS module receives the information from the GPS satellite in NMEA (National Marine Electronics Association) format and thus it reveals the position information. This information got from the GPS antenna has to be sent to the Base station wherein it is decoded. For this we use GSM module which has an antenna too. Thus we have at the Base station; the complete data about the vehicle.

Along with tracking the vehicle, the system is used for security applications as well. Each passenger/employee will have an ID of their own and will be using a remote containing key for Entry, Exit and Panic. The Panic button is used by the driver or the passenger so as to alert the concerned of emergency conditions. On pressing this button, an alarm will be activated which will help the passenger/employee in emergencies and keep them secure throughout the journey. The vehicle can also be immobilized remotely.

INTRODUCTION:

Of all the applications of GPS, Vehicle tracking and navigational systems have brought this technology to the day-to-day life of the common man. Today GPS fitted cars, ambulances, fleets and police vehicles are common sights on the roads of developed countries. Known by many names such as Automatic Vehicle Locating System (AVLS), Vehicle Tracking and Information System (VTIS), Mobile Asset Management System (MAMS), these systems offer an effective tool for improving the operational efficiency and utilization of the vehicles.

GPS is used in the vehicles for both tracking and navigation. Tracking systems enable a base station to keep track of the vehicles without the intervention of the driver whereas navigation system helps the driver to reach the destination. Whether navigation system or tracking system, the architecture is more or less similar. The navigation system will have convenient, usually a graphic display for the driver which is not needed for the tracking system. Vehicle tracking systems combine a number of well-developed technologies.

To design the VMSS system, we combined the GPS’s ability to pin-point location along with the ability of the Global System for Mobile Communications (GSM) to communicate with a control center in a wireless fashion. The system includes GPS-GSM modules and a base station called the control center.

Let us briefly explain how VMSS works. In order to monitor the vehicle, it is equipped with a GPS-GSM VMSS system. It receives GPS signals from satellites, computes the location information, and then sends it to the control center. With the vehicle location information, the control center displays all of the vehicle positions on an electronic map in order to easily monitor and control their routes. Besides tracking control, the control center can also maintain wireless communication with the GPS units to provide other services such as alarms, status control, and system updates.

The design takes into consideration important factors regarding both position and data communication. Thus, the project integrates location determination (GPS) and cellular (GSM) – two distinct and powerful technologies in a single system.

VMSS is based on a PIC microcontroller-based system equipped with a GPS receiver and a GSM Module operating in the 900 MHz band. We housed the parts in one small plastic unit, which was then mounted on the vehicle and connected to GPS and GSM antennas. The position, identity, heading, and speed are transmitted either automatically at user-defined time intervals or when a certain event occurs with an assigned message (e.g.; accident, alert, or leaving/entering an admissible geographical area).

The GPS Module outputs the vehicle location information such as longitude, latitude, direction, and Greenwich Time every five minutes. The GSM wireless communications function is based on a GSM network established in a valid region and with a valid service provider. Via the SMS provided by the GSM network, the location information and the status of the GPS-GSM VMSS are sent to the control center. Meanwhile, the VMSS receives the control information from the control center via the same SMS. Next, the GPS-GSM VMSS sends the information stored in the microcontroller via an RS-232 interface.

There are two ways to use the VMSS’ alarm function, which can be signified by either a buzzer or presented on LCD. The first way is to receive the command from the control center; second way is to manually send the alarm information to the control center with the push of a button.

The base station consists of landline modem(s) and GIS workstation. The information about the vehicle is received at a base station and is then displayed on a PC based map. Vehicle information can be viewed on electronic maps via the Internet or specialized software. Geographic Information Systems (GIS) provides a current, spatial, visual representation of transit operations. It is a special type of computerized database management system in which geographic databases are related to one via a common set of location coordinates.

STAGES OF VMSS

STAGE 1:

1. Driver starts his trip from the transport office.
2. VMSS transmits the Driver I.D and the Vehicle I.D along with the position of the vehicle to the base station.

STAGE 2:

1. Taxi picks up the employee/passenger from their residence.
2. VMSS transmits the Passenger I.D and the Vehicle I.D along with the position of the vehicle to the base station. Therefore base station will be able to keep a track of the vehicle and thus the employee/passenger.

STAGE 3:

1. Taxi drops the employee/passenger to the workplace.
2. VMSS transmits the Passenger I.D and the Vehicle I.D along with the position of the vehicle to the base station.

STAGE 4:

1. Taxi picks the employee/passenger from the workplace.
2. VMSS transmits the Passenger I.D and the Vehicle I.D along with the position of the vehicle to the base station. Therefore this enables the base station to estimate the time if required and also keep a track of the vehicle, passenger and the driver.

STAGE 5:

1. Taxi drops the employee/passenger to their residence.
2. VMSS transmits the Passenger I.D and the vehicle I.D along with the position of the vehicle to the base station and makes sure that the job is 100% complete.
   ]]> http://electrofriends.com/projects/microcontrollers/vehicle-monitoring-and-security-system/feed/ 46 http://electrofriends.com/projects/microcontrollers/digital-ic-tester/ http://electrofriends.com/projects/microcontrollers/digital-ic-tester/#comments Thu, 20 Nov 2008 14:38:32 +0000 Ranjith http://electrofriends.com/?p=15 An Integrated Circuit tester (IC tester) is used to test Integrated Circuits (ICs). We can easily test any digital IC using this kind of an IC tester. For testing an IC, we need to use different hardware circuits for different ICs; like we need a particular kind of tester for testing a logic gate and another for testing flip flops or shift registers which involves more complication and time involved will also be more. So here’s an IC tester to overcome this problem. Unlike other IC testers, this is more reliable and easier since we don’t need to rig up different kind of circuits for different kind of ICs, each time we need to test them.

   Unlike the IC testers available in the market today which are usually expensive, this IC tester is affordable and user-friendly. This IC tester is constructed using 8951 microcontroller along with a keyboard and a display unit. It can test digital ICs having a maximum of 24 pins. Since it is programmable, any number of ICs can be tested within the constraint of the memory available. This IC tester can be used to test a wide variety of ICs which includes simple logic gates and also sequential and combinational ICs like flip-flops, counters, shift registers etc. It is portable and easy to use.

   The block diagram of the programmable digital IC tester is as shown in below. It consists of two 8951 microcontroller ICs, a 24-pin IC socket, a keyboard unit, a display unit and indicators.

   To test a particular digital IC, one needs to insert the IC into the IC socket and enter the IC number using the keyboard and then press the “ENTER” key. The IC number gets displayed in the 7-segment display unit.

   Four LEDs are provided as indicators. If the IC being tested is a logic gate, then each of the 4 indicator LEDs correspond to the 4 gates of the IC. In any other case wherein the inserted IC is not a logic gate, all the 4 LEDs work as a single indicator.

   

   Digital IC Tester

   

   Digital IC Tester

   Block diagram of Programmable Digital IC Tester:

   

   Block diagram

   ]]> http://electrofriends.com/projects/microcontrollers/digital-ic-tester/feed/ 100 http://electrofriends.com/projects/computer-programming/sudoku-solver-using-c/ http://electrofriends.com/projects/computer-programming/sudoku-solver-using-c/#comments Thu, 20 Nov 2008 10:01:11 +0000 Ranjith http://electrofriends.com/?p=249 You have seen it in the news papers, you have seen it in the magazines or in the web sites, you might have sat hours ‘n hours to solve it. Yes, it is the king of all number puzzles, it is “SUDOKU”.

   We bring to you the ultimate solution for all your struggles, The SUDOKU Solver.

   As you know, now a days mathematical puzzle-SUDOKU is in boom all over the world. Sudoku is a 9X9 matrix with nine 3×3 sub-matrices, that we need to fill by entering the numbers from 1 through 9, without the repetition of the a number in the rows, columns or in the sub matrices.

   

   Figure: 1- Sudoku Problem

   We can get the Sudoku puzzle in ease by different means, as discussed. You might have struggled a lot to solve the same. To be true, even me too. Here I developed a fast and robust package, that solves the puzzles, that are not easy to solve by hands. It will solve the Sudoku entered in fraction of a milli-second and will display the solved result.

   

   Figure: 2 - Sudoku Result

   Click here to download the executable files

   When the code executes, a blank Sudoku will be displayed with 9×9 red boxes. The user is needed to enter the numbers corresponding to the source puzzle (Figure 1). To enter this, user should use the arrow keys to cruse to the required box. The selected box will be highlighted with a blue boundary. You have to enter the number through the keyboard. Once you have done entering all the numbers in the puzzle just hit the ‘Enter’ key on the keyboard till you get the solved result (Figure 2). If the Sudoku cannot be solved by this program a message will be displayed telling that the given puzzle cannot be solved.

   ]]> http://electrofriends.com/projects/computer-programming/sudoku-solver-using-c/feed/ 41 http://electrofriends.com/projects/computer-programming/shuffle-game-using-c/ http://electrofriends.com/projects/computer-programming/shuffle-game-using-c/#comments Thu, 20 Nov 2008 09:51:40 +0000 Ranjith http://electrofriends.com/?p=245 If you think playing a game as this is a child’s play, try a hand on this and think again. Its all about how you plan on making your next move. All the best, have fun.

   Here is a simple game developed in C graphics which is called ‘The Shuffle Game’. We believe u have already played many of such games where in you need to arrange scrambled pieces of a picture, alphabets or numbers. In the present program you have been given a matrix of 16 squares of which 15 are assigned with 15 different numbers and 1 is left out blank (empty space for movement of the remaining boxes) which are all shuffled. All you have to do is arrange these numbers in order as shown in the picture given below. The number of moves and the number that have been arranged by you in the proper position will be continuously displayed on the screen.  The controls  are as given below.

   Controls:

   You can move the boxes by using the arrow keys on your keyboard or by simply clicking on the box which you want to move into the empty space. While using the arrow keys, if you want to move the box left to the empty space just hit the left arrow button. Similarly you can move the boxes on the top, bottom or right of the empty box by hitting the up, down or right arrows respectively. In case you want to restart the game all over again just click the ‘RESTART’ button or if you want to quit the game, all you have to do is to click the ‘EXIT’ button on the screen.

   

   Shuffle game using C++

   Source code:

   #include<stdio.h>
   #include<stdlib.h>
   #include<conio.h>
   #include<graphics.h>
   #include<dos.h>
   #include<alloc.h>
   #include<process.h>
   union REGS in,out;
   void *buf;
   int size,count=0,px,py,rnd[4][4],correct=0;

   float octave [7]={130.81,146.83,164.81,174.61,196,220,246.94};

   int callmouse()
   {    in.x.ax=1;
   int86(51,&in,&out);
   return 1;

   }
   void mouseposi(int &xpos,int &ypos,int &click)
   {   in.x.ax=3;
   int86(51,&in,&out);
   click=out.x.bx;
   xpos=out.x.cx;
   ypos=out.x.dx;
   return ;
   }
   int  mousehide()
   {
   in.x.ax=2;
   int86(51,&in,&out);
   return 1;
   }
   void done(void)
   {
   int i,j;
   mousehide();
   j=0;
   int n;
   for(i=1;i<=15;i++)
   {
   n=random(7);
   sound(octave[n]*4);
   delay(300);
   setfillstyle(1,2);
   bar(42+j,425,68+j,455);
   setfillstyle(1,0);
   bar(68+j,425,72+j,455);
   j=j+29;
   }
   nosound();
   delay(1000);
   for(j=0;j<382;j+=2)
   {
   for(i=0;i<575;i+=2)
   {
   putpixel(26+i,25+j,4);
   putpixel(26+i,460-j,4);
   putpixel(25+j*3/4,28+i*3/4,2);
   putpixel(595-j*3/4,458-i*3/4,2);
   delay(0);
   }
   }
   delay(1000);
   settextstyle(1,0,5);
   setcolor(14);

   outtextxy(320,300,”http://electrofriends.com”);
   outtextxy(321,300,”http://electrofriends.com”);
   delay(500);
   getch();
   exit(0);
   }
   checknum(int mat[4][4])
   {
   int k=0,i,j;
   correct=0;
   for(i=0;i<=3;i++)
   {
   for(j=0;j<=3;j++)
   {
   k++;
   if(k==mat[i][j])
   correct++;
   }
   }
   gotoxy(10,11);
   printf(“NUMBERS ARE IN CORRECT POSITION IS ..: %d  “,correct);
   if(correct==15)
   {
   bar(130,40,480,80);
   settextstyle(1,0,4);
   outtextxy(300,60,”CONGRAGULATIONS !”);
   done();
   }
   else
   {
   bar(20,415,480,463);
   j=0;
   for(i=1;i<=correct;i++)
   {
   setfillstyle(1,1);
   bar(42+j,425,68+j,455);
   setfillstyle(1,0);
   bar(68+j,425,72+j,455);
   j=j+29;
   }
   }
   return 0;
   }

   void  move(int &a,int &b,int &c,int &d,int &w,int &x,int &y,int &z,int &num)
   {
   if(a>192 && b>190 && c<403 && d<404)
   {
   sound(600);
   count++;
   gotoxy(10,9);
   printf(“NUMBER OF MOVES..: %d   “,count);
   mousehide();
   size=imagesize(a,b,c,d);
   free(buf);
   buf=malloc(size);
   getimage(a,b,c,d,buf);
   bar(a,b,c,d);
   putimage(w,x,buf,COPY_PUT);
   w=a;
   x=b;
   y=c;
   z=d;
   if(num==1)
   {
   rnd[px][py]=rnd[px+1][py];
   rnd[px+1][py]=0;
   px++;
   }
   else if(num==2)
   {
   rnd[px][py]=rnd[px-1][py];
   rnd[px-1][py]=0;
   px–;
   }
   else if(num==3)
   {
   rnd[px][py]=rnd[px][py+1];
   rnd[px][py+1]=0;
   py++;
   }
   else if(num==4)
   {
   rnd[px][py]=rnd[px][py-1];
   rnd[px][py-1]=0;
   py–;
   }
   checknum(rnd);
   callmouse();
   delay(40);
   nosound();
   }
   return ;
   }

   main()
   {
   int a1,b1,cl,a,b,c,d,w,x,y,z,key,p=0,q=0;
   int g=DETECT,m,ext=0,rst=0,rx,ry,num,i,j;
   initgraph(&g,&m,”c:\\TC\\bgi”);
   randomize();
   gotoxy(50,9);
   printf(“http://electrofriends.com”);

   do
   {
   correct=0;
   count=0;
   gotoxy(10,9);
   printf(“NUMBER OF MOVES..: %d   “,count);

   gotoxy(10,11);
   printf(“NUMBERS ARE IN CORRECT POSITION IS ..: %d  “,correct);
   setfillstyle(SOLID_FILL,4);
   setcolor(15);
   for(j=200;j<360;j+=50)
   {
   for(i=200;i<365;i+=50)
   {
   rectangle(j-1,i-1,j+46,i+46);
   bar(j,i,j+45,i+45);
   }
   }
   rectangle(192,190,403,404);
   settextstyle(1,0,3);
   for(i=0;i<=3;i++)
   {
   for(j=0;j<=3;j++)
   {
   rnd[i][j]=0;
   }
   }
   for(i=0;i<=15;i++)
   {
   do
   {
   rx=random(4);
   ry=random(4);
   }  while(rnd[rx][ry]);
   rnd[rx][ry]=i;
   }
   char ab[10];
   settextjustify(CENTER_TEXT,CENTER_TEXT);
   q=p=0;
   for(i=0;i<=3;i++)
   {
   for(j=0;j<=3;j++)
   {
   if(rnd[i][j]!=0)
   {
   sprintf(ab,”%d”,rnd[i][j]);
   outtextxy(225+p,217+q,ab);
   }
   else
   {
   setfillstyle(1,0);
   px=i;py=j;
   bar(199+p,199+q,247+p,247+q);
   w=199+p;
   x=199+q;
   y=247+p;
   z=247+q;
   }
   p+=50 ;
   }
   p=0;
   q+=50 ;
   }
   bar(130,40,480,80);
   bar(10,425,480,455);
   setfillstyle(SOLID_FILL,4);
   rectangle(534,374,591,411);
   bar(535,375,590,410);
   outtextxy(561,390,”EXIT”);
   rectangle(484,419,591,456);
   bar(485,420,590,455);
   outtextxy(538,433,”RESTART”);
   setcolor(4);
   rectangle(10,10,610,470);
   rectangle(15,15,605,465);
   setcolor(14);
   rectangle(12,12,607,467);
   settextstyle(1,0,4);
   outtextxy(300,60,”SHUFFLE GAME”);
   line(150,85,450,85);

   j=0;
   delay(1500);
   int n;
   for(i=1;i<=15;i++)
   {
   n=random(7);
   sound(octave[n]*4);
   delay(300);
   setfillstyle(1,2);
   bar(42+j,425,68+j,455);
   setfillstyle(1,0);
   bar(68+j,425,72+j,455);
   j=j+29;
   }
   nosound();
   setfillstyle(SOLID_FILL,0);
   bar(30,425,480,455);
   settextstyle(2,0,5);
   outtextxy(250,425,”YOU CAN USE ARROW BUTTONS OR MOUSE TO MOVE BLOCKS.”);
   outtextxy(250,450,”      PRESS ANY KEY TO START……..” );

   getch();
   bar(20,415,480,463);
   callmouse();
   do
   {
   gotoxy(10,20);
   mouseposi(a1,b1,cl);
   if(a1>w && a1<y && b1>x+50 && b1<z+50 && cl==1)
   {
   num=1;
   move(w,x+50,y,z+50,w,x,y,z,num);                   //up
   }
   if(a1>w && a1<y && b1>x-50 && b1<z-50 && cl==1)
   {
   num=2;
   move(w,x-50,y,z-50,w,x,y,z,num);              //down
   }
   if(a1>w+50 && a1<y+50 && b1>x && b1<z && cl==1)
   {
   num=3;
   move(w+50,x,y+50,z,w,x,y,z,num);                   //left
   }
   if(a1>w-50 && a1<y-50 && b1>x && b1<z && cl==1)
   {
   num=4;
   move(w-50,x,y-50,z,w,x,y,z,num);                   //right
   }
   if(kbhit())
   {
   key=getch();
   switch(key)
   {
   case 72: num=1;
   move(w,x+50,y,z+50,w,x,y,z,num);           //up
   break;
   case 80: num=2;
   move(w,x-50,y,z-50,w,x,y,z,num);           //down
   break;
   case 75: num=3;
   move(w+50,x,y+50,z,w,x,y,z,num);          //left
   break;
   case 77: num=4;
   move(w-50,x,y-50,z,w,x,y,z,num);          //right
   break;
   }
   }

   if((a1>535 && a1<590 && b1>375 && b1<410 && cl==1) || key==27)
   done();
   rst=0;
   if(a1>485 && a1<590 && b1>420 && b1<455 && cl==1 )
   rst=1;
   } while(rst==0);
   } while(rst!=0);
   closegraph();
   }

   If you find difficult to compile the code, Download source code, executable file and supporting files here.

   You have seen it, you have played it, you have seen the source code. Now its your turn to show us how creative your thinking is!! We hope you have got all the ideas that you need to build such a game with C graphic. If you are successful do send us a copy of the game. We will see through that your name comes on this site.

   ]]> http://electrofriends.com/projects/computer-programming/shuffle-game-using-c/feed/ 1