ANTI HELMET THEFT SYSTEM

Semester 6 Electronics and communication A - Mini Project

Guided by: Satheesh N Kaimal

Presented by: Brolwin Thankachan, Dileep Kadavarath, Hebin Aloor,

Job Pulikkottile

Introduction•Helmets are mostly left out in the open•Relatively easy pickings for even most unskilled snatchers•Not many care to complain as they are impossible to trace•Helmet usage can improve chances of head on clash survival three fold•Recent urges by the motor vehicle department makes them unavoidable too•More people are willing to use helmets with their premium motorbikes•Better certified helmets costing north of 1000 are not expendable

Introduction•Our proposed system is designed to put an end to helmet theft•A helmet with loud alarms wont be appealing for a thief•Operating on high frequency waves reduces antenna size•Final product is idealised to be located within the helmet shell•This protects the circuit from destruction by the thief•Finalised product is advised to use a sealed rechargeable lithium battery

Block Representation:Transmitter

Encoder IC RF transmitterPower Supply

Block Representation:Receiver

Atmega8MicrocontrollerDecoder ICRF receiver

Power Supply

DTMFdecoder

Block explanation•DTMF Decoder – decodes key presses from a device•Encoder and Decoder – They convert parallel data to serial and vice versa for transmission and reception respectively.•Transmitter – It transmits data from encoder.•Receivers – It receives data from transmitter, and outputs it to decoder.•Microcontroller – it has the responsibility of sounding the alarm according to the signal received from the decoder.• Power supply – power is provided by batteries for both units.

Working•Base unit broadcasts a monotonous signal•Receiver section on the helmet checks for its authenticity•The control logic on the helmet sounds the alarm when the received signal is turned low, which happens when the receiver goes out of range.•The receiver unit can be disabled using DTMF tones from a phone.

TransmitterCircuit

ReceiverCircuit

Features of Atmega8•High-performance, Low-power 8-bit Microcontroller•Up to 16MIPS Throughput at 16MHz•8Kbytes of In-System Self-programmable Flash program memory•512Bytes EEPROM•1KByte Internal SRAM•Write/Erase Cycles: 10,000 Flash/100,000 EEPROM•Data retention: 20 years at 85°C/100 years at 25°C

Features of Atmega8•23 Programmable I/O Lines•Operating Voltages•4.5V - 5.5V• Speed Grades : 0 - 16MHz• Power Consumption at 12Mhz, 5V

– Active: 3.6mA– Idle Mode: 1.0mA– Power-down Mode: 0.5µA

Pin Out

Power Supply•We are using 9V 6LR61 Alkaline battery per receiver & transmitter sections•Regulated 5V supply using LM7805 IC•The output of LM7805 will be in the range of 4.9 and 5.1V•The main power consuming components include RF transmitter module, HT12 Encoder & Atmega8 microcontroller in transmitter section•The main power consuming components include RF receiver module, HT12 Decoder & Atmega8 microcontroller in receiver section•All the above components around 5V supplied by LM7805

DTMF(Dual Tone Multi Frequency)

•DTMF signaling is used for telecom signaling over analog telephone lines in the voice frequency band between telephone handsets and other communication devices and the switching center•DTMF is a method of instructing switching system of the telephone numbers to be dialed, or to issue commands to switching system

DTMF Keypad Table

•Row and Column represents low and high frequency respectively•The multiple tones are the reason for calling the system multi frequency•Tones are then decoded by switching centers to determine which keys are pressed

DTMF Decoder IC (HT9170B)

•Operating voltage is 2.5V-5.5V•No external filter required •Excellent performance•18 pin package•3.58 crystal or ceramic resonator•18 pin package

Encoder•HT12E used here is a 18-pin DIP•Operating voltage-2.4V~12V for the HT12E• Low power and high noise immunity CMOS technology• Low standby current: 0.1A (typ.) at VDD=5V• It has 8 address lines• It can accept up to 4 bits of parallel data from the microcontroller•Output serial data is fed into a external RF transmitter module

Decoder•HT12D used here is a 18-pin DIP•Operating voltage-2.4V~12V for the HT12D• Low power and high noise immunity CMOS technology• Low standby current• It has 8 address bits to identify its corresponding encoder• It can accept serial data from the RF receiver module & output up to 4 bits of parallel data to the microcontroller

RF Modules• In this RF system, the digital data is represented as variations in the amplitude of carrier wave. This kind of modulation is known as Amplitude Shift Keying•This RF module comprises of an RF Transmitter and an RF Receiver. The transmitter/receiver (Tx/Rx) pair operates at a frequency of 315 MHz

Buzzer•We are using a piezoelectric

buzzer•The piezo buzzer produces

sound based on reverse of the piezoelectric effect. The generation of pressure variation or strain by the application of electric potential across a piezoelectric material is the underlying principle•The buzzer produces a same

noisy sound irrespective of the voltage variation applied to it

Receiver Flowchart

Start

Check DV

Valid DV:Compare

True:Turn Off receiver

False:Continue normal

Operation

Invalid DV:Continue normal

Operation

Check transmission

From transmitter

No reception:Sound alarm

Reception:Do nothing

Result and future scope

•User can now leave the helmet on the two-wheeler while parking, without any particular actions involved.• The security system kicks in automatically and makes the

helmet locked onto the vehicle and if it leaves the vicinity, the buzzer on it will sound continuously.• Future scope of improvement in our system may include

provisions to turn off the devices while security is not needed, i.e., while the bike is running.• Further developments can be done by replacing the buzzer

with a proper speaker that can playback the voice of user warning the thief to place the helmet back

Conclusion

•Our proposed project hopes to put an end to helmet theft.•This effortless automated system is poised to make our everyday better

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• "Heinrich Hertz: The Discovery of Radio Waves". Juliantrubin.com. Retrieved 2011-11-08.

• http://www.1728.org/freqwave.htm

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Thank you.