iButton electronic lock

Since iButton DS1990A introduced in market from Dallas Semiconductor (MAXIM), it has been used in many applications concerning security, access control systems etc. In this project we will use iButton as a key to an electronic lock. This electronic lock can use many different kinds of iButtons and can store up to 9 different keys. One of the keys is the master key and is permanent stored in memory. With the use of master key we can add or remove slave keys.

This electronic lock can be used with any type of iButtons you may already have, since the only thing needed is the internal serial number, that's different for every iButton. The command used to read the serial number is the same for all iButtons. The iButton family code that goes with every iButton, can be anything and is calculated as part of the whole serial number. We must also notice that DS1990A series iButtons are the cheapest.
 

 

This electronic lock designed to work stand-alone and it's easy to construct. What the user sees (outside of the door for example) is a iButton socket and a led. From inside the door, we can open it using a simple push button. For the actual lock of the door a solenoid and a bold are used. Solenoid must be rated at 12Vdc. iButtons serial numbers stored in memory can be removed and updated when needed. One master key is used to manage the rest of them. Totally a number of 9 different keys can be stored in memory.

Schematic diagram is shown at figure 1. The circuit is build around an Atmel AT89C2051(U1) microcontroller. The port 1 (P1) of mcu is used to connect a 7-segment common anode led display. This led display will be used on the programming of additional keys. For the same reason a push-button labelled SB1 is connected on P.3.7. Storage of iButtons serial numbers is done on a 24C02 EEPROM (U3). It is connected on P3.4 (SDA) and P3.5 (SCL) of U1. The external iButton socked is connected on port P3.3 via XP2 pin array. The rest of components VD4, R3, VD5 and VD6 are used for protection of mcu ports. One pull-up resistor R4 is used as required from 1-wire protocol. An additional iButton socket is connected parallel with the predefined at pins XS1. This one is used for programming the keys. The door OPEN button is connected on P3.2 through XP1 connector, using the same protection components as above. The solenoid that does the lock is connected on XT1 connector. Solenoid is controlled from a power MOSFET IRF540 (VT3). Diode VD7 is added to protect MOSFET from voltage strikes due to solenoid inductance. Transistor VT3 is controlled from VT2, which reverses the logic state that's appears on P3.0, so on VT3 we have output 0V and 12V. This additional transistor is useful as it translates the mcu logic levels to 0V and 12V, capable to drive the solenoid.

3V LED Chaser

General

There are many 9V chaser circuits that seem to waste about 7V when driving LEDs that are only about 2V. This project is unique, because it uses only two inexpensive alkaline battery cells totaling 3V for power. Since most of the waste is eliminated, the cells last a long time.

Unlike the other circuits, this one flashes the LEDs for only about 30ms each, further extending the battery life. For user convenience, it has a stepper speed control and a brightness control. At slower speeds and with reduced brightness, the battery life is further extended considerably. Mounted in a circle, the LEDs appear to rotate as they step from one to the next.

Specifications
� Battery: Two alkaline cells (AA size were used in the prototype)
� Battery Life: AA cells C cells D cells
Minimum speed and brightness 8 months 2 years 4.9 years
Medium speed and brightness 6 months 1.5 years 3.6 years
Maximum speed and brightness 2 weeks 1.5 months 3.6 months
� Stepper speed: 2 LEDs/sec to 2 revolutions/sec
� Brightness: Controlled with Pulse Width Modulation, from very dim to 161mcd (very bright)
� Pulse Width Modulation frequency: 1.4KHz very bright to 6KHz very dim
� LED current: 15mA pulses, reduced to 10.5mA at maximum Pulse Width Modulation
� LED voltage drop: 1.76V (measured, not rated) @ 10.5mA
� Minimum battery voltage (total of both cells): <1.24V, circuit is running but LEDs are not lit
1.6V, LEDs are very dim at maximum brightness
2.0V, LEDs reach almost full brightness, battery replacement is recommended.
� Radio interference: None

Circuit Description
The 74HC Cmos ICs are rated for a 2V to 6V power supply for high-speed logic circuits. They continue to operate at a much lower voltage but no longer meet high-speed logic specifications. To reach high speeds, their output current can momentarily exceed 400mA (low voltage drop) but thermal considerations limit maximum continuous output current to 20mA. Perfect for driving LEDs!

� IC2 is a 10 stage Johnson counter/decoder. On the rising edge of each clock pulse its outputs step one-at-a-time. It drives the anode of each conducting LED toward the positive supply.
� IC1a is a standard Cmos inverter Schmitt-trigger oscillator with C3 and C4 totaling 800nF for a very slow step rate. R2 is the speed control pot with R1 limiting its maximum speed. It clocks IC2 and feeds the inverters/drivers. D1 and R3 reduce its output high time to 30mS.
� IC1d, IC1e, IC1f and IC1b are paralleled inverter/drivers for a low output voltage drop and drive the emitter of T1 to ground.
� IC1c is another standard Cmos inverter Schmitt-trigger oscillator. R5 is its Pulse Width Modulation control and with D3 performs dimming of the LEDs. D2 and R4 extend the PWM�s maximum pulse width.
� T1 is a transistor that is used as a PWM switch. R7 limits maximum LED pulse current.
� C1 bypasses the battery�s supply voltage at low frequencies and C2 bypasses at high frequencies.

Construction
The ten LEDs mount on a Compact-Disc which is glued to a plastic box with contact cement. The box houses the Veroboard circuit in its lower main part with the battery holder in its lid. Multiconductor ribbon cable joins the LEDs to the circuit. The pots mount on the sides of the box.
 

ATMEL 89 Series Flash Microcontroller

 

Open GPS Tracker

  The Open GPS Tracker is a small device which plugs into a $20 prepaid mobile phone to make a GPS tracker. The Tracker responds to text message commands, detects motion, and sends you its exact position, ready for Google Maps or your mapping software. The Tracker firmware is open source and user-customizable.

The current supported hardware platform is:

* Tyco Electronics A1035D GPS module
* Motorola C168i AT&T GoPhone prepaid mobile phone
* Atmel ATTINY84-20PU AVR microcontroller

Project requires no interface chips! All you need is a GPS module, a phone, an ATTINY84, a voltage regulator, a PNP transistor, and a few passive components. This is a commercial grade tracker and is currently a second-generation stable beta V0.17.

This version stores messages while out of GSM coverage, and forwards them when it regains coverage.
 

 The current supported hardware platform is:

• Tyco Electronics A1035D GPS module
• Motorola C168i AT&T GoPhone prepaid mobile phone
• Atmel ATTINY84-20PU AVR microcontroller 
  
  

Microcontroller Based Event Counter

The project presented here is based on world’s most powerful micro-controller based on intel’s mcs-51 family , generally known as intel-8051. We have used its derivative atmel-89c2051.

Event Counter Block Diagram Operation: Any type os active or passive switch can be connected to the con1 connected
When ever that switch closes event will be counted inside the microcontroller and would be displayed on the 2×16 lcd. Switch could be capacitive,inductive or any other type which suits to your construction.
Ic3 an optocoupler will receive incoming count pulse at pin3 and output from pin 5 is connected to p3.4 pinof the ic2 microcontroller,
Two line by 16 character on each line (2×16) is used in nibble mode and maximun count can reach upto 65536 there after it will reset to 00000.
SW1 is manual reset switch to make the counter to reset to zero.
Circuit is driven by 9v 1 ampere transformer connected to PCON1
Diode D1-D4 forms bridge circuit C1,c2 and c3 are filter capacitors and are part of power supply section..
Ic1 7805 is 5v regulator ic to give stablised supply to microcontroller. Ld1 is a power indication led. R1 controls the current flowing thrugh led LD1 Crystal X1 along with C5 and C6 gives the necessary clock to microcontroller.
Capacitor C4 and R2 gives the required reset pulse to microcontroller.

8051 Based code Lock With dial up

8051 Based code Lock More and more devices are coming every day to protect your house and property from thiefs .Present project is also one of them. The project presented here is based on world’s most powerful intel’s mcs-51 family of microcontroller atmel at89c51.
8051 Based code Lock With dial up Block Diagram When ever somebody tries to open your latch by entering wrong numbers.
After three wrong retries. The project takes the following action
1) Sounds an siron to attract your or public attention .
2) It will call a telephone number you wanted the device should call you in such case.
3) I will make 5 attempts to call you at the interval of one second and deliver the emergency message stored in speech ic.
4) During this operation the key board will get lock and will not except any key press.
5) Key lock will be indicated by an led LD4 connected on top of kaypad, will glow permanently till the time keypad is lock.
6) Key pad will get unlock only after 5 retries of the phone.
The project comprises of the following blocks:
• Microcontroller
• Password store key
• Telephone store key
• Indication leds
• 4×3 matrix key pad
• serial eprom to store the password and telephone number.
• Speech circuit
• Amplifier circuit
• Off-hook circuit
• Dialer circuit
• Latch relay
• Power supply

IVRS System For Industrial Control

The mentioned project is based on the world,s most powerful intel controller 8051. Most of the services provided in todays world are voice interactive, you call up your bank and computrised voice will speak to you,and guide you to enter a particular number from your phone to get the desired service.this service is only available through the fast speed computers and having huge ammount of memory.we emplemented interactive service for industrial applications.


IVRS Block Diagram
This device has the following blocks
1.ring detector circuit comprises of bridge rectifire d1-d4 and opto coupler u8 mct2e
2. Watch dog timer comprising of ic 7400 and u7 ic 4047
3. Dtmf decoder ic u6 8870
4. Dialer circuit relay rl2 transister q1
5. Off hook circuit relay rl1 and transformer tr1 c5 and r8.
6. Microcontroller circuit the central processor 89c51
7. Speech circuit ic uv1 1840 where all the messages are stored
8. Amplifire circuit ic uv2 lm 386
9. Security storage ic 93c46
10. And load controller where relay boards will be connected p1
11. Power supplay circuit ic u10 7805,bridge rectifires d1-d4
12. Capacitor c1 and c2
13. Fire sensor is connected to connector p2 connector

8051 Based Electronic Eye

This project is based on high sensitive IR Transmitter & Receiver having range of more than 15 feet. When you are away for your house any if anyone tries to enter the house by any means the device shouts CHOR-CHOR-CHOR-PAKDO-PAKDO-PAKDO Continuously more than 40 seconds, that is enough to chase the thief, he will run away so your house is protected. The device not only shouts but also dials out previously stored telephone number ( which you have stored) and gives you the message CHOR- CHOR- CHOR. So that you understand that something is wrong at your house, you can immediately call up your neighbor to look after your house. 8051 Based Electronic Eye Block Diagram Working Description of Electronic Eye with Dial-Up
1. Keep the transmitter & receiver aligned in a straight position facing each other about a distance more than 2 meter but not less than that.
2. Connect the two 1.5v cells inside the bobbin of transmitter module properly.
3. Connect the telephone line to telephone line input of the circuit.
4. Connect the mains cord to 230v AC of your supply & switch on the supply.
5. When you switch on the supply if the circuit initially plays any alarming message only press the reset switch to make the message off.
6. The message will reset only after completing the total message when you have pressed the reset switch SW1.
7. If the message is continuously playing after the reset switch has been pressed means that the transmitter (TX) & receiver (RX) is not properly aligned or it is being obstructed.
8. Switch on the power supply if no message is played first step is to store the telephone number of the concerned person.
9. To store the telephone number press the off hook switch SW2. Dial the telephone number by the keypad.
10. By doing that the green LED on the PCB will be glowing showing that the telephone number has been dialed.
11. Wait for 5 to 6 seconds after dialing out the telephone number then take off the hand from the off hook switch means that your number has been stored.
12. After that obstruct the beam created between infrared receiver (RX) & transmitter (TX) immediately after that you hear the alarming message (chor chor ….) through the speaker.
13. At the same time it will dial out the telephone number which has been stored.
14. You can hear the same alarming message through telephone line for 30 seconds.
15. The message will be stopped for 30 seconds & again after 30 seconds you can hear the same message through telephone line till no one is resetting the circuit.

Pc to Pc Fiber - optic communication

The above project uses two nos transreceiver modules ,and the circuit communicates at 9600 kbps. ‘c’ codes comes with along with project.

Pc to Pc Laser Communication Block Diagram

TELE-SAFE HOME SECURITY SYSTEM

The Project Team considered many different design alternatives for the
Tele-Safe Home Security System. However, time and money constraints
limited the choices.
• There are different types of sensors which are available that could have
been used to trigger the system such as:
• Infrared sensors
• Heat sensors
• Motion sensors
• Magnetic sensors
• There are different methods that could have been used to connect the
sensors to the system such as:
• Wireless/Bluetooth
• There are different methods that could have been used to power the system
such as:
• One single source powering the whole system instead of multiple
sources.
• The circuitry of the system could have been smaller and more compact.
• The casing for the system and the sensor could have been smaller and
lighter – Perhaps a lighter material?
• To seal the case we could have used something else other than tape.

The four critical components of the project include:
•The Atmel 89C51 Microcontroller.
Used to arm and disarm the operational amplifier.
•The auto-dialer.
When triggered, a phone number is dialed.
•The infrared motion detector.
Creates an infrared beam.
Becomes triggered when the beam is broken.
•The operational amplifier.
Provides the required voltage to the infrared motion
detector when armed.

GPS Rover

This project consists of a mobile robot vehicle which can be controlled using data from an onboard GPS unit and a remote laptop base station. The robot uses advanced communication mediums in order to control and monitor its movement. Although the robot itself has a limited use, the purpose of developing the vehicle is a proof of concept. The combined technology used in this project may lead to future development in the area of GPS navigation.

A GPS receiver is used to determine the current location of the robot. A wireless communications device with WiFi capability captures the GPS raw data from the receiver and transmits the data to a base station. Based on the GPS data readings, the base station calculates the direction the robot needs to travel in order to reach the final destination. The base station does not take into account the mechanical issues with the physical structure of the robot or the obstacles that may be in the way of the vehicle. The base station sends data and commands via wireless link to a microprocessor onboard the vehicle. The microprocessor controls the physical motion of the vehicle, taking into account the obstacles that may be in the way and adjusts the steering accordingly. There are always accuracy issues in any mechanical device. Some of the issues include wheel slippage, steering adjustments and speed of communication between mechanical and electrical devices. The microprocessor provides the control and speed to handle these mechanical problems and adjusts the robot’s motion accordingly.

Intelligent Combat Robot Ver-02

We cannot forget 9/11 when 101 people including nine foreigners and 14 policemen have lost their lives while about 300 people were injured in the worst terror attack seen in the country in which desperate men fired indiscriminately at people.Being an ex– defense person , my blood was boiling as our brave soldiers were fighting the militants to free all the hostages from mumbai hotels.

Intelligent Combat Robot Block Diagram  It struck an adea in my mind, why cant we make a robot to tackle such type of situation.
This combat robo is an improved version of my previous robot which I designed years ago named SPY ROBO.
Circuit operation receiver:
RF433-RX is 433mhz radio receiver which receives the transmitted codes from the remote place transmitted by the transmitter these codes are converted to digital format and out put is available to the pin no 2 of the ic2 master micro-controller, this is the rx pin of inbuilt UART of the micro-controller. We are using uart to receive our codes at 1200 boud rate.. Based on the input codes master will give command to slave microcontroll ic3 and robo will behave as follows.
a. moves in forward direction
b. moves in reverse direction,
c. speed controls in both the direction
d. it can even turn left or right while moving forward or in reverse direction.
e. Instent reverse or forward running without stopping
f. In case of bump,moves reverse turn left or right and wail for the next instruction .
g. On the spot left or right turn to pass through the nerrow space
h. We have also added head light, back light.and turing lights to left a right . These lights automatically comes on while robo is in Movement.
i. Pin no 7,8,9.11,12,and 13 of the master micro-controller are connected to the slave micro-controller ic3 to give the following command pulses to the slave micro-controller ic3 pin 2,3,6,7,8 and 9,
1.Start/stop
2. Increase speed
3. Increase speed
4. Direction change
5. Turn left
6. Turn right
Slave microcontroller ic3 pins 15,16,17,18,19 are connected to ic4 motor driver ic, pin17 of the slave gives the pulse width modulation pulse which is connected to pin 1 and 9 of ic4 this is EN pin of ic 4 Pin 18 and 19 controlls one motor m1 and pin 15 and 16 of the slave controller controls the m2 motor.

Electronic muscle stimulator

IT is also know as muscle enhancers.
This is an electronic muscle stimulator circuit that stimulates nerves of that part of your body where electrodes are attached. Can be used for diy electron stimulation.It is useful to relieve headache and muscle pain and revive frozen muscles that impair movement. It’s mainly electronic muscle stimulation aid is removing cellulitis and build up you muscles.
The system comprises two units: muscle stimulator and timer.
Fig. 1 shows the circuit of the muscle stimulator. IC 7555 is wired as an astable multivibrator to generate about 80Hz pulses.
Using potentiometer VR1 you can control the intensity of current sensing at the electrodes. The brightness level of LED1 indicates the amplitude of the pulses. If you want to increase the intensity level, replace the 1.8 kΩ resistor with 5.6 kΩ or higher value up to 10 kΩ.
X1 is a small mains transformer with 220V primary to 12V, 100/150mA secondary. It must be reverse connected, i.e., connect the secondary winding to the collector of T2 and ground, and primary winding to the output electrodes. The output voltage is about 60V but the output current is so small that there is no threat of electric shock.

DIY Electronic muscle stimulation circuit diagram

Electrodes are made of small, thinguage metallic plates measuring about 2.5×2.5 cm2 in size. Use flexible wires to solder electrodes and connect to the output of the device. Before attaching metal electrodes to the body, wipe them with a damp cloth.
After attaching the electrodes to the body (with the help of elastic bands on velcro straps), flip switch S1 to activate the circuit and rotate the knob of intensity-control preset VR1 very slowly until you feel a slight tingling sensation.
Fig. 2 shows the timer circuit. It uses IC NE555 wired in monostable mode. Initially, when you press switch S2, the monostable triggers and its output goes high for 10 minutes. Thereafter, its output goes low to give a beep sound from the piezobuzzer and lights up the red LED (LED2) indicating that muscle stimulation time is over.

Electronic muscle stimulator timer circuit

muscle stimulator timer schematic

Assemble the timer with a separate switch and a 9V DC battery in the same cabinet as the stimulator. Tape the electrodes to the skin at opposite ends of the chosen muscle and rotate VR1 knob slowly until you sense light itching when the muscle stimulation circuit is powered on. At the same time, flip switch S2 to start the timer for counting the time. At the end of the timing cycle, the piezobuzzer beeps. Each session
should last about 10 minutes.

Caution: Heart patients and pregnant women should not use this device. Also, do not attach electrodes to burns, cuts, wounds or any injury. Consult your physician before using this circuit.

MICROPROCESSOR BASED RAILWAY SYSTEM

The aim of this project is to demonstrate the incorporation of computer method in railway traffic control to improve, safety, speed of handling the traffic and reliability. Here we employ the microprocessor (Intel 8085) to handle the signaling, track changing and gate operation and to monitoring the traffic. The system starts with the tracking if the train is sensed at the station side or starts with the gate operation (i.e. gate closing and opening) along with the track changing if the train is sensed at the gate side. Once the train arrival is sensed at a distance of about 3 kms the microprocessor performs the gate operation along with the track changing, the identification of the train is done at a distance of 3 kms accordingly the particular operation is performed by the processor. Depending upon the priority of the incoming train, the unengaged track is given for train halting.

Universal Electronic Credit Card

An average Americans owns 9 credit cards and as a result they continue to
increase the chance of fraud that costs companies billions of dollars every year. By
unifying all cards and increasing the difficulty of discovering the numbers, we can both
reduce the clutter and the money lost due to fraudulent purchases.
This makes for a good project because we have to start dealing with size
constraints since credit cards have to fit an ISO 7813 standard requiring that they be .
76mm thick. We are shooting to get the card to an average thickness of that size meaning
that we have to consider size when we start making the card. This is becoming a very
common problem in commercial devices because consumers demand smaller and smaller
objects as technology makes it feasible.
Benefits
· Unify multiple cards
· Eliminate scratches and demagnetization
· Increase security
· Upgradeable in software.
Features
· TI-MSP430 microprocessor
· Electromagnetic coils instead of permanent magnets
· Physical security as well as possible software encryption
· Real time clock
· Super thin battery
· LED display

Home Security System

The purpose of this project is to add an element of security to the average household. The idea is to scare potential intruders away by sounding an alarm while they attempt to enter a house equipped with this system. The system is intended to be very precise and sensitive, while also being cost effective. The project is practical in that the user interface is very simple. The entire system can be controlled from a single console, and merely a few keystrokes are required to perform any of the system’s functions.

1.2 Functions

This system takes in a user pass-code to perform all of its actions. Using this pass-code, the user can arm and disarm the system. The user can also change the pass-code. The state of the system will be displayed using LEDs. It will display red for the arm state, green for the disarm state, and yellow for the pass-code changing state. While the system is in the arm state, the system alarm will sound if any of the break-beam sensors are tripped. The alarm can only be disabled by entering the correct user pass-code. The system will also automatically clear an incorrect pass-code once it is fully entered.

1.3.1 Power Supply

The supply provides dual 5 volt DC outputs. One of the outputs is dedicated to the break-beam sensors and the Piezo horn, and the other output supplies the rest of the components.

1.3.2 HC12 Microcontroller

The HC12 controls what state the system is in. It takes inputs from the keypad. It outputs to the LCD to show when the keypad is being pressed. It also outputs to the three state LEDs.

1.3.3 Keypad

The 16-Key keypad allows the user to control the system. It is coupled with a decoder that communicates with the microcontroller directly.

1.3.4 LCD

The LCD displays a ‘*’ whenever a key is pressed on the keypad. This is simply to show a response to user input. Another function that the LCD serves is its auto-clear function. If all 6 digits of the pass-code have been entered and they are incorrect, the LCD clears the screen.

1.3.5 Sensors 

The sensors used in this system are infrared emitter-detector pairs. They output a voltage HI when the beam is broken. TTL logic is used to configure these sensors with the state indicating LEDs. The output of that logic is sent to the alarm.

1.3.6 Alarm

A Piezo horn is used as an alarm for the system. This horn is sufficient for the prototype. In a real world setting, this horn can be easily replaced with a higher outputting horn. The alarm is turned on by logic output of the sensors and the state indicating LEDs. 

2.1 Power Supply

The block diagram for the power supply is shown in figure 2a below. This configuration allows the system to be plugged into any standard wall socket.

Figure 2a

The circuit diagram for the power supply is shown in figure 2b. An important characteristic of this diagram is the use of two 7805 regulator chips. These chips provided the dual outputs that were needed to power the system properly.

Figure 2b