8051 BASED STOPWATCH

The project uses seven segment displays and 89S51 controller to control the stopwatch.The stopwatch is enabled to count from 0 to 99.After 99 the watch toggles to 00.A nice start for beginners.Go and have some fun with programming and hardware.C program and design file are attached below.

DOWNLOAD:C PROGRAM AND DESIGN FILE

Bidirectional Visitor Counter

The circuit consist of very basic components like seven segments,8051 microcontroller and buttons can be replaced by IR sensor circuits.Button 1 is used to increment the counter while button 2 decrements the counter.The counter shows an increment up to 9.This project will be a very good start for begineers in programming.Just assemble the circuit and amaze your friends.Coding and design file of the  project is attached below.

DOWNLOAD:C PROGRAM AND DESIGN FILE

 

 

8051 Based Wind Turbine

A 8051 based wind turbine model consist of a moving rotor assembly consisting of a DC motor including the blades for converting wind energy to low speed rotational energy. The generator component includes the electrical generator, the control electronics, and most likely a gearbox (e.g. planetary gearbox, adjustable-speed drive or continuously variable transmission) component for converting the low speed incoming rotation to high speed rotation suitable for generating electricity.

The whole generator system is mounted on a stepper motor configuration which enables the system to move 180  ͦ towards left and 180  ͦ towards right direction. This enables the system to move 360  ͦ and choose the direction of the wind anytime. This eliminates the dependency of wind turbine on the direction of wind.

The system is connected with a controlling keypad to move the stepper motor in desired direction. At the base of the turbine tower is a energy storing system made of resistors and capacitors to store the AC voltage produced during the rotation of turbine blades. The capacitor stores the fluctuating voltage and converts it into constant voltage supply to drive LED or other kind of load.

An LCD is provided along with keypad to display the condition of wind speed depending on the speed of the moving blades. The LCD also displays the degree at which the turbine system mounted on stepper motor is moving. 

The system is connected with an Atmel 89S52 microcontroller which controls and manages the working of whole assembly including stepper motor, keypad and LCD display.

Key features of this project are:

Ø  A DC motor is used to generate the power from moving wind.

Ø  Capability of turbine to rotate in 360  ͦ direction to choose the optimum direction of flowing wind.

Ø  Controlling of system using a keypad present at the base of the tower.

Ø  Uses a LCD to display the angle rotated by the turbine assembly through stepper motor.

Ø  The power is stored in a capacitor circuit to convert the fluctuating voltage into dc voltage.

Ø  8051 based turbine system to control the turbine mechanism and stepper motor controlling mechanism.

Ø  The microcontroller and LCD works on a +5V supply.

DOWNLOAD:C PROGRAM FOR THIS PROJECT

Low cost Audio amplifier using LM386

All that is needed to build an audio amp are a few external components most of which are decoupling capacitors. It is well suited to low power applications and runs just fine on a 9 volt battery or any voltage supply from 4-12 volts. It has a low quiescent current drain of only 4mA so it won’t kill a battery right away if you leave it on and idle. The gain is internally set to 20 but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value from 20 to 200. An increase in bass frequency can be facilitated by adding a 10K resistor and .033 uf capacitor in series between pins 1 and 5.

Multilevel Car Parking System

Automatic multistoried car parking system helps to minimize the car parking area. In the modern world, where parking-space has become a very big problem and in the era of miniaturization, it is become a very crucial necessity to avoid the wastage of space in modern, big companies and apartments etc.

A display is provided at the ground floor which is basically a counter that displays number of cars in each floor. It informs whether the floors are fully filled with the cars or is it having place in a particular floor or not. There is facility of lift to carry the car to up and down. Movement of Lift is controlled by stepper motor. An indicator with a green and red LED is kept in all the floors to indicate whether the lift is busy or is it ready to take the car up or down. If the red LED glows that means the lift is already engaged and the person has to wait for the green LED to glow. In this project we have provided three floors of a building for car parking. Maximum storage capacity of each floor is given as ten. Storage capacity can be changed according to the requirement.

Any one can enter to first or second floor. The third floor in this model is for VIP’s only. Therefore when VIP’s are to be entering they are expected to enter their password and they will be taken to the third reserved floor. The password will be of 4 digits. The processor checks for the password entered and if it is found to be wrong, a siren is heard. So when a password is entered, the processor checks for it and it is compared with right password. It indicates whether it is the correct one or not.

When the car enters the lift, the LDR detects its presence and sends a signal to glow RED LED indicating that the lift is busy. It also sends a signal to motor which makes the motor to rotate. After RED LED glows the lift will take the person and the car up to the floor where the space for parking is available. (For VIP it will be the third floor). When the lift reaches the first floor, the processor compares  the filled amount to that of the already fed capacity of that floor, and if it finds that the first floor is fully filled , it goes to the second floor and thus the procedure stops here. As soon as a car is placed in a particular floor, the display counter at the ground floor increments as to indicate the floor capacity has decreased by one. After the lift places the car in a particular floor, it comes back to its normal position and that time, the motor that drives it , also stops. Now processor sends signal to glow GREEN LED indicating that lift is free.

When a person needs to come down from a particular floor to ground floor, he is expected to focus the headlight onto the LDR placed in that floor. Now sensor section sends signal to motor that the lift has to be send back to that particular floor and sends a signal to glow RED LED indicating that the lift is busy. As soon as the lift reaches that particular floor car should come inside the lift, the display counter at the ground floor decrements by one as to indicate the floor capacity has increased by one. Lift comes back to its normal position and that time, the motor that drives it, also stops. Now processor sends signal to glow GREEN LED indicating that lift is free.

If there no parking taking place, the processor carries out the job according to the following priority:-

1.     It checks whether any password is entered.

2.     It checks whether any car is entered to lift.

3.     It checks whether any car headlight is pressed in front of  LDR placed in each floor.

It is like a round robin system.

Wireless Station Intimation System

Our project demonstrate one such example were Radio Wave is employed in a way which is helpful to us.This project is designed and developed for helping the passengers traveling in train and bus especially during night. The people who are not aware of the station on which one should get down will find this very helpful.Here the station name is displayed and announced simultaneously when the station is about to reach which can assist both literate and illiterate.
The RF technology is used in the project to communicate between the transmitter and receiver. Each transmitter has a unique binary code which is transmitted continuously to space in a particular range. This signal is captured by the receiver when it reaches in its range. So in the case of a train, the transmitter placed in the station is detected by the receiver in the train and the binary code is
processed to give out the station name display and audio corresponding to the binary code in the receiver. A LCD unit is used for displaying the station name and a speaker is used for the announcement.

Main parts of this project are :


1. Power Supply
The power supply section is the section which provide +5V for the transmitter section to work. IC LM7805 is used for providing a constant power of +5V.

2. Encoder
This section contains the identity of the transmitter. An encoder can be a device used to change a signal (such as a bit stream) or data into a code. The code serves any of a number of purposes such as compressing
information for transmission or storage, encrypting or adding redundancies to the input code etc.

3. RF Transmitter
This section transmits the binary data to space in a particular range based on the antenna used. This signal is received by the receiver and it compares the binary code to find the corresponding station name from
the database.

1.1.2. Receiver

1. Power Supply
The power supply section is the section which provide +5V for the transmitter section to work. IC LM7805 is used for providing a constant power of +5V.

2. Decoder
A decoder is a device which does the reverse of the encoder, undoing the encoding so that the original information can be retrieved.

3. Microcontroller
Unlike microprocessors, microcontrollers are generally optimized for specific applications. As a result the peripherals can be simplified and reduced which cuts down the production cost.

4. RF Receiver
The RF signal transmitted by the transmitter is detected and received by this section of the receiver. This binary encoder data is sent to the decoder for decoding the original data.

5. LCD
This is the output unit in the receiver section. The station name is displayed on this display unit when the receiver comes in the range of the transmitter.

6. Voice Alert
This is another output unit in the receiver. This gives the voice alert of the station reached based on the RF transmitter signal received.Voice recording ic APR9600 is used here.

Traffic Light Controller

The circuit is made using AT89s2051 or can be replcad by 89s51.In this sequence of coloured lights:

• Illumination of the green light allows traffic to proceed in the direction denoted,
• Illumination of the yellow light denoting, if safe to do so, prepare to stop short of the intersection, and
• Illumination of the red signal prohibits any traffic from proceeding.

   

Joule Thief Circuit

Joule thief is a nickname for a minimalist self-oscillating voltage booster that is small, low-cost, and easy-to-build; typically used for driving light loads. It can use nearly all of the energy in a single-cell electric battery, even far below the voltage where other circuits consider the battery fully discharged (or "dead"). Hence the name suggests the notion that the circuit is stealing energy or "Joules" from the source

 

The circuit uses the self-oscillating properties of the blocking oscillator, to form an unregulated voltage boost converter. As with all power conversion technology, no energy is actually created by the circuit. Instead, the output voltage is increased at the expense of higher current draw on the input. As a result, the amount of power entering the circuit is the same as the amount leaving, minus the losses in the conversion process.

Clap Switch

Here’s a clap switch free from false triggering. To turn on/off any appliance, you just have to clap twice. The circuit changes its output state only when you clap twice within the set time period. Here, you’ve to clap within 3 seconds.

The clap sound sensed by condenser microphone is amplified by transistor T1. The amplified signal provides negative pulse to pin 2 of IC1 and IC2, triggering both the ICs. IC1, commonly used as a timer, is wired here as a monostable multivibrator. Trigging of IC1 causes pin 3 to go high and it remains high for a certain time period C3. This ‘on’ time (T) of IC1 can be calculated using the following relationship:

T=1.1R7.C3 seconds

where R7 is in ohms and C3 in microfarads. On first clap, output pin 3 of IC1 goes high and remains in this standby position for the preset time. Also, LED1 glows for this period The output of IC1 provides supply voltage to IC2 at its pins 8 and 4. Now IC2 is ready to receive the triggering signal. Resistor R10 and capacitor C7 connected to pin 4 of IC2 prevent false triggering when IC1 provides the supply voltage to IC2 at first clap.

On second clap, a negative pulse triggers IC2 and its output pin 3 goes high for a time period depending on R9 and C5. This provides a positive pulse at clock pin 14 of decade counter IC 4017 (IC3). Decade counter IC3 is wired here as a bistable.

Each pulse applied at clock pin 14 changes the output state at pin 2 (Q1) of IC3 because Q2 is connected to reset pin 15. The high output at pin 2 drives transistor T2 and also energises relay RL1. LED2 indicates activation of relay RL1 and on/off status of the appliance. A free-wheeling diode (D1) prevents damage of T2 when relay de-energises

A very simple IR remote control switch for an electrical appliance

This project describes a technique of adding the remote control feature to an electrical appliance. The goal is to construct a black box where you can plug-in your 240V AC appliance and control the ON and OFF operations with a ir remote.The good thing about this project is that it does not use any microcontroller and is only based on the CD4017 decade counter IC.

Microcontroller-Based Solar Charger

As the sources of conventional energy deplete day by day, resorting to alternative sources of energy like solar and wind energy has become need of the hour.

Solar-powered lighting systems are already available in rural as well as urban areas. These include solar lanterns, solar home lighting systems, solar streetlights, solar garden lights and solar power packs. All of them consist of four components: solar photovoltaic module, rechargeable battery, solar charge controller and load.

In the solar-powered lighting system, the solar charge controller plays an important role as the system’soverall success depends mainly on it. It is considered as an indispensable link between the solar panel, battery and load.

The microcontroller-based solar charge controller described here has the following features:

1. Automatic dusk-to-dawn operation of the load.
2. Built-in digital voltmeter (0V-20V range)
3. Parallel- or shunt-type regulation
4. Overcharge protection
5. System status display on LCD
6. Deep-discharge protection
7. Low battery lock
8. Charging current changes to ‘pulsed’ at full charge
9. Low current consumption
10. Highly efficient design based on microcontroller
11. Suitable for 10-40W solar panels for 10A load

courtesy:electronics4you

DOWNLOAD:HEX FILE 

A SIMPLE DARK DETECTING CIRCUIT USING LDR

                                          

Displaying numbers on seven segment for begineers

A seven-segment display (SSD), or seven-segment indicator, is a form of electronic display device for displaying decimalnumerals that is an alternative to the more complex dot-matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, and other electronic devices for displaying numerical information.

A seven segment display, as its name indicates, is composed of seven elements. Individually on or off, they can be combined to produce simplified representations of the arabic numerals. Often the seven segments are arranged in an oblique (slanted) arrangement, which aids readability. In most applications, the seven segments are of nearly uniform shape and size (usually elongated hexagons, though trapezoids and rectangles can also be used), though in the case of adding machines, the vertical segments are longer and more oddly shaped at the ends in an effort to further enhance readability.

Each of the numbers 0, 6, 7 and 9 may be represented by two or more different glyphs on seven-segment displays.

here is a circuit which shows the interfacing of a seven segment with 8051 microcontroller and displays the numbers from 0 to 7.The numbers on the seven segment can be controlled by the port 1 buttons.

Download file for 89s52:

https://rapidshare.com/files/4150646605/sevensegment.zip

TEXT DISPLAY ON LCD USING 89S51/52 MICROCONTROLLER

Video showing the characters displayed on lcd using 89s52

A static message can be displayed on a 16x2 LCD by interfacing it to the microcontroller (AT89C51). The same message can also be displayed with certain animated effects like moving, blinking etc. This topic explains how to create dynamic effects with the text displayed in LCD.A string or message can be displaced on  LCD by sending its characters to data register after configuring the command register of LCD. To create dynamic effects, a specific command instruction is sent to LCD via microcontroller AT89C51.  The different command codes for LCD are tabulated below:

Hex Code	Command to LCD Instruction Register
1	Clear screen display
2	Return home
4	Decrement cursor
6	Increment cursor
5	Shift display right
7	Shift display left
8	Display OFF, cursor OFF
A	Display OFF, cursor ON
C	Display ON, cursor OFF
E	Display ON, cursor blinking
10	Shift cursor position to left
14	Shift cursor position to right
18	Shift the entire display to the left
1C	Shift the entire display to the right
80	Force the cursor to the beginning of the 1st line
C0	Force cursor to the beginning of the 2nd line
38	Use 2 lines and 5x7 matrix

 courtsey : www.engineersgarage.com