Technology

SMART HELMET

Vehicle accidents are most common if the driving is inadequate and hence these necessary methodologies may help in reducing the rate of accidents to a greater extent. Driver drowsiness and drunken driving may have fatal results and by using smart helmet we can detect and stop them from driving. This project involves measure and controls the eye blink using IR sensor also alcoholic and smoke sensor and alert them upcoming risk of driving that can save their precious lives.

 Introduction:

Road accidents are a major problem in nowadays due to heavy rush and speedy life. Vehicle accident become more common due to inadequate driving. Most of the accident are due to drunken driving where the driver loses his control over the vehicle which may result in fatal accidents. Also driver drowsiness is recognize as an important factor in vehicle accident. This project involves use of IR sensor, Smoke sensor and alcohol sensor to minimize the risk of accidents to a considerable extent. No proper methodology is adopted. Increasing rate of traffic is also a major reason of most of the accidents. Widening of roads is not an alternative in India.

Working:

Here 18f4520 interfaced with different sensors to prevent accidents.  This unit  continuously scans for various parameters of bike. Also the µc scans for alcohol and eye blink sensor.

We have designed a sensor  which continuously monitors the number of times the eye blinks. If the eye blink count decreases that means the driver is sleepy .In that case a buzzer is operated.

If the driver is found to have alcohol in the breath, the ignition is turned off by the µc .And hence the possibility of accident is avoided. Smoke sensor will sense smoking condition of driver.

Finally Smart helmet used to avoid accidents.

 

 Specifications:

Power supply:

In Power supply design the bridge rectifier and capacitor input filter produce an unregulated DC voltage of 15v which is applied at the input of 7812.As the minimum dropout voltage is 2v for IC 78012, the voltage applied at the input terminal should be at least 7 volts.C1 (1000 µf / 65v) is the filter capacitor and C2 and C3 (0.1 pF) is to be connected across the regulator to improve the transient response of the regulator.

Assuming the drop out voltage to be 2 volts, the minimum DV voltage across the capacitor C1 should be equal to 15volts.

 

A supply of 12 volts and 2 Ampere we have to use a 7812 as the voltage regulator and transformer input 15volts AC and current rating 2Ampere.

 

Microcontroller IC:

  1. C compiler optimized architecture:
  2. Optional extended instruction set designed to optimize re-entrant code
  3. 100,000 erase/write cycle Enhanced Flash program memory typical
  4. 1,000,000 erase/write cycle Data EEPROM memory typical
    1. Flash/Data EEPROM Retention: 100 years typical
    2. Self-programmable under software control
    3. Priority levels for interrupts
    4. 8 x 8 Single-Cycle Hardware Multiplier
    5. Extended Watchdog Timer (WDT):
  5. Programmable period from 4 ms to 131s
    1. Single-supply 5V In-Circuit Serial
  6. Programming™ (ICSP™) via two pins
    1. In-Circuit Debug (ICD) via two pins
    2. Wide operating voltage range: 2.0V to 5.5V
    3. Programmable 16-level High/Low-Voltage
    4. Detection (HLVD) module: Supports interrupt on High/Low-Voltage Detection
  7. Programmable Brown-out Reset (BOR) with software enable option

 

Circuit Diagram:

 

Circuit_Smart Helmet
Circuit_Smart Helmet

Working:

The above circuit diagram shows the circuit of Smart Helmet. The AC supply given to the step down transformer in the circuit, it converts 230V power supply into 12V DC supply as we need it for circuit operation further. The voltage regulator IC7805 also connected in circuit for giving 5V DC supply to our PIC 18F4520 IC. The 12MHz crystal oscillator also used for triggering .

In this circuit we have used    Alcohol Sensor To Detect Weather The Person have Consumed The Alcohol Or Not. Mq3 Sensor is used as Alcohal detector. This Sensor Is An Analog Sensor And The Output Is In Analog Form. So The Output Of This Sensor Is Provided To The Input Of The Adc Which Will Convert This Analog Output In Digital Input To The Microcontroller. We have designed a  sensor  which continuously monitors the number of times the eye blinks. If the eye blink count decreases that means the driver is sleepy .In that case a buzzer is operated. And smoke detector is also use to detect the percentage of smoke.

Thus in this way accidents can be avoided by using smart helmets.

LIQUID CRYSTAL DISPLAY:

LCD is used in a project to visualize the output of the application. We have used 16×2 LCD which indicates 16 columns and 2 rows. So, we can write 16 characters in each line. So, total 32 characters we can display on 16×2 LCD.

LCD can be also used in a project to check the output of different modules interfaced with the microcontroller. Thus LCD plays a vital role in a project to see the output and to debug the system module wise in case of system failure in order to rectify the problem.

ALCOHOL SENSOR:

Alcohol Sensor Is Used To Detect Weather The Person P9OHave Consumed The Alcohol Or Not. The Sensor Which We Have Used Is Mq3 Sensor. This Sensor Is An Analog Sensor And The Output Is In Analog Form. So The Output Of This Sensor Is Provided To The Input Of The Adc Which Will Convert This Analog Output In Digital Input To The Microcontroller. As We Are Using The Arm Microcontroller, The Arm Microcontroller Have In Build Adc. This Analog Signal Will Be Given At The Input Of The In Build Adc To Convert Analog Into Digital Signal.

Sensitive Material Of Mq-3 Gas Sensor Is Sno2, Which With Lower Conductivity In Clean A. When The Target Alcohol Gas Exist, The Sensor’s Conductivity Is More Higher Along With The Gas Concentration Rising.

Please Use Simple Electro Ccuit, Convert Change Of Conductivity To Correspond Output Signal Of Gas Concentration.

Mq-3 Gas Sensor Has High Sensitity To Alcohol, And Has Good Resistance To Disturb Of Gasoline, Smoke And Vapour. The Sensor Could Be Used To Detect Alcohol With Different Concentration; It Is With Low Cost And Suitable For Different Application.

Eye Blink  Sensor:

Here We Are Connecting An  Based  Sensor. The 50 Ohm Resister Is Used For Current Limiting. The Current Through The Led Is 5v / 50 Ohm = 100 Mamp, Which Is High For An Led. But To Increase The Range Of The  Sensor We Are Using A Lower Range Resistor (50 Ohm).

On The Receiver Side We Have Connected The  Receiver In Reverse Bias. So As Soon As The Light Falls In The  Receiver  ,The Anode Voltage Increases And When The Anode Voltage Is More Than The Cathode Voltage Then The Led Is In Forward Bias Mode And Start Conducting.

 

IR Sensor:

IR SENSOR

The basic concept of IR(infrared) obstacle detection is to transmit the IR signal(radiation) in a direction and  a signal is received  at the IR receiver when the IR radiation bounces back  from a surface of the object.

Actually when LED glow it will transmit light & from obstacle light get reflect back & receive by another led.

 

Power Supply:

 

The basic step in the designing of any system is to design the power supply required for that system. The steps involved in the designing of the power supply are as follows,

1) Determine the total current that the system sinks from the supply.

2) Determine the voltage rating required for the different components

 

The bridge rectifier and capacitor input filter produce an unregulated DC voltage of 15v which is applied at the input of 7812.As the minimum dropout voltage is 2v for IC 78012, the voltage applied at the input terminal should be at least 7 volts.

C1 (1000 µf / 65v) is the filter capacitor and C2 and C3 (0.1 pF) is to be connected across the regulator to improve the transient response of the regulator.

Assuming the drop out voltage to be 2 volts, the minimum DV voltage across the capacitor C1 should be equal to 15volts.

 

PIC 18F4520 Micro Controller:

Here we have used PIC18F4520

 FEATURES:

  • C compiler optimized architecture with optional extended instruction set.
  • 100,000 erase/write cycle Enhanced Flash program memory typical
  • 1,000,000 erase/write cycle Data EEPROM memory typical
  • Flash/Data EEPROM Retention: > 40 years
  • Self-programmable under software control
  • Priority levels for interrupts
  • 8 x 8 Single Cycle Hardware Multiplier
  • Extended Watchdog Timer (WDT): Programmable period from 41 ms to 131s
  • Single-Supply 5V In-Circuit Serial
  • Programming™ (ICSP™) via two pins
  • In-Circuit Debug (ICD) via two pins
  • Wide operating voltage range: 2.0V to 5.5V

 

Power supply design of the Project:

 

The average voltage at the output of a bridge rectifier capacitor filter combination is given by

 

 

Vin(DC) = Vm – Idc / 4 f C1

 

Where , Vm=√2 Vs  and Vs = rms secondary voltage

 

Assuming Idc to be equal to max. load current, say 100mA

 

C = 1000 Gf / 65v , f=50hHz

 

 

19 = Vm – 0.1 / 4*50*1000*10¯6

 

19= Vm – 0.1 /  0.2

 

Vm=19.5 volts

 

Hence the RMS secondary Voltage

 

Vrms = vm /  √2

 

= 19.5 /  √2

 

=19,5 / 1.4421

 

=13.5 volts

 

So we can select a 15v secondary Voltage.

So in conclusion for a supply of 12V and 2A we have to use a 7812 as the voltage regulator and transformer I/p 15v AC and current rating 2Ampere.

 

      The reasons for choosing the bridge rectifier are,

  1. The TUF is increased to 0.812 as compared the full wave rectifier.
  2. The PIV across each diode is the peak voltage across the load = Vm, not 2Vm as in the two diode rectifier

Output of the bridge rectifier is not pure DC and contains some AC ripples in it. To remove these ripples we have used capacitive filter, which smoothens the rippled out put that we apply to 7805 regulators IC that gives 5V DC. We preferred to choose capacitor filters since it is cost effective, readily available and not too bulky.

 

CRYSTAL CIRCUIT:

 

Pins OSC1 & OSC2 are provided for connecting a resonant network to form oscillator. Typically a quartz crystal and capacitors are employed. The crystal frequency is the basic internal clock frequency of the microcontroller. The manufacturers make available PIC designs that can run at specified maximum & minimum frequencies, typically 1 MHz to 16 MHz.

 

P2    P1     P2    P1    P2     P1    P2    P1     P2     P1   P2     P1     P2   P1

 

 

 

 

State 1           State 2    State 3  State 4  State 5    State 6

 

One Machine Cycle

 

 

CRYSTAL OSCILLATOR

 

Here we are connecting two ceramic capacitors which are basically used for filtering. That is to give a pure square wave to the µC.

The basic rule for placing the crystal on the board is in such a way that it should be as close to the µC as possible to avoid any interference in the clock.

 

Why 11.0592 MHz?                             

Serial data communication needs often dictate the frequency of the oscillator because of the requirement that internal counters must divide the basic clock rate to yield standard communication baud rates.  If the basic clock frequency is not divisible without a reminder, then the resulting communication is not standard.

 

 

Here we keep

SPBRG = 143 ;for 4800 baud rate and 71 for 9600 baud rate

BRGH = 1 ; high speed

Therefore      11.0592Mhz / 16 (143 +1);

11.0592Mhz / 16(144);

11.0592Mhz / 2304;

4800 bits/sec (a standard communication baud rate)

 

 

 

Schematic verification

 

               Layout                   Verification
                    C1                        1000uf
                    C2                        100nf
                    C3                        100nf
                    C4                        1000uf
                    C5                        33pf
                    C6                        33pf
                    C7                        10uf
                    R1                        10k
                    D1                        IN4007
                    D2                        IN4007
                    D3                        IN4007
                    D4                        IN4007
                    D5                        IN4007

 

Table.1 schematic verification table

 

 

 

 

 

PCB ARTWORK:

 

STEPS OF PCB DESIGNING:

  1. Copper Clad or Glass EPOXY Fiber PCB Board.
  2. Glossy Photo Paper or Magazine Paper (I Used Glossy Photo Paper).
  3. Copper Etching Chemical (Ferric Chloride or Hydrogen Peroxide) (I Used Ferric Chloride)
  4. 2 Containers (1 Small And 1 Big) (Make Sure That The Smaller One Gets Fitted Between The Bigger One, There Must Be Space Between Them)
  5. Hand Drill Machine (With 1mm Bit).
  6. Laser Printer (If You Don’t Have Then Drawn the Designs with Permanent Marker on Board).
  7. PCB Designs On Your Computer (Make Your Own In Proteus Software).
  8. First make Schematic Diagram after that Layout.

Step 1: Design Your Schematics and Print Them

Make your circuit design on Proteus Software.
Print The Design On Glossy Photo Paper Or Magazine Paper Using Laser Printer Only.
If you don’t have a Laser Printer then you can draw the design with Permanent Marker on The COPPER CLAD or GLASS EPOXY FIBER Board.

 

  Step 2: Prepare Your Copper Clad Board

To preare the copper clad board:

  1. Apply liquid soap or dishwasher liquid on the coper clad board.
  2. Rub steel wool on it till it gets shiny.
  3. Rub it with Scotch-Brite.
  4. Soak it with water.
  5. Finally, clean it with a cloth.

Now Your Copper Clad Board Is Ready For Toner Transfer (Toner Onto The Board).

Step 3: Toner Transfer (Transfer of Toner onto the Board)

For the toner transfer:

  1. Heat the iron to its maximum setting.
  2. Cut the design and place it up side down on the board.
  3. Slowly move and press the iron on the board with pressure for 20-25 minutes.

Step 4: Washing the Board and Completely Removing the Paper

After Heating, Wash The Board With Water Till the Paper Completely Gets Removed, Now Only Black Lines Are Left on the board do not remove those lines. After That IF There Are any Non Transferred Lines Then Grab a Permanent marker And Draw The Lines.

 

TEST RESULTS:

  1. Give VCC and GND to microcontroller.
  2. Check voltage between 61-62 pins (XTAL1, XTAL2) it should be 2.5V.
  3. Check available voltage pin 57 RESET —1.4V.
  4. If all these voltage are coming then the microcontroller is working properly
  5. LCD check VCC and GND write a RTN for display any message on LCD if the message does not come CLK the supply again also check the data lines for any opens or short

Conclusion:

  1. We have successfully implemented the circuit of Smart Helmet on PCB.
  2. We made less costly, small in design, less complex and more useful.
  3. We can renovate this circuit for further use like temperature sensing.

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