Block definition Project consists of vehicle section and toll gate section In vehicle section, each vehicle having its own RFID In Tollgate section, vehicle id to be received by the RFID receiver,which is transferred to the microcontroller through decoder Then microcontroller performs data storage and also which comparesavailability of the amount in the money card And also details about vehicle stored into the database of thecomputer through serial communication Then gate section which opens automatically In case person has not having money, then gate will not open Database which contains entire database about the vehicle
Hardware Tools Power Supply Unit Microcontroller AT89S51 Encoder/Decoder RF module Serial communication RS232,Max232
Power supplyAC Input(Transformer)RectifierBridgeRectifierVoltageRegulator(LM7805)MCU
Power Supply CircuitVDDVDDC70.1 uFJP2220 VAC12- +D11432U27805132VINGNDVOUTC6100 uFC5470 uFR4220 ohmD2LED
Power Supply• The operation of power supply circuits built using filters, rectifiers, andthen voltage regulators. Starting with an AC voltage, a steady DCvoltage is obtained by rectifying the AC voltage• Then filtering to a DC level, and finally, regulating to obtain a desiredfixed DC voltage.• The regulation is usually obtained from an IC voltage regulator Unit,which takes a DC voltage and provides a somewhat lower DC voltage,Which remains the same even if the input DC voltage varies, or theoutput Load connected to the DC voltage changes.
Need of Microcontroller A microcontroller (also MCU or µC) is afunctional computer system-on-a-chip. Itcontains a processor core, memory, andprogrammable input/output peripherals. Microcontrollers include an integrated CPU,memory (a small amount of RAM, programmemory, or both) and peripherals capable ofinput and output.
Features of MCU• 4K Bytes of In-System Programmable (ISP) FlashMemory• 4.0V to 5.5V Operating Range• Fully Static Operation: 0 Hz to 33 MHz• 128 x 8-bit Internal RAM• 32 Programmable I/O Lines• Two 16-bit Timer/Counters• Six Interrupt Sources• Full Duplex UART Serial Channel• Low-power Idle and Power-down Mode• Watchdog Timer , Dual Data Pointer
Serial communication ATMEL microcontroller and write the code to initializethe UART and use it to send and receive data Data you need to transmit and it will do the rest. It transmits data at standard speeds of 9600,19200 bpsetc The advantage of hardware UART is that you just need towrite the data to one of the registers of UART and yourdone, you are free to do other things while UART istransmitting the byte. UART automatically senses the start of transmission ofRX line and then inputs the whole byte and when it hasthe byte it informs you(CPU) to read that data from oneof its registers
Voltages The USART input/output uses 0V for logic 0 and5V for logic 1. The RS-232 standard (and the COM port) use+12V for logic 0 and –12V for logic 1. To convert between these voltages levels we needan additional integrated circuit (such as Maxim’sMAX232).
UART pins in AT89S51 The UART always transmits data on pin P3.1/TX The UART always receives data on pin P3.0/RX The RS-232 standard defines lots of other signalsother than TX and RX used for handshaking.
RF TRANSMITTER The transmitter output isup to 8mW at 433.92MHzwith a range ofapproximately few meters It accepts both linear anddigital inputs It can operate from 1.5 to12 Volts-DC It is approximately thesize of a standard postagestamp.
HT-12E ENCODERFeatures Operating voltage:2.4V~12V for the HT12E Low power and high noise immunityCMOS technology Minimum transmission word’s of4 words for the HT12E Built-in oscillator needs only 5% resistor Data code has positive polarity Minimal external components HT12E: 18-pin DIP/20-pin SOP package
RF RECEIVER It also operates at433.92MHz, and has asensitivity of 3uV. It operates from 4.5 to5.5 volts-DC, It has both linear anddigital outputs.
HT12D DECODER Operating voltage: 2.4V~12V Low power and high noise immunity CMOS technology Low standby current Capable of decoding 12 bits of information Binary address setting Received codes are checked 3 times Address/Data number combination - HT12D: 8 address bits and 4 data bits Built-in oscillator needs only 5% resistor Valid transmission indicator Easy interface with an RF transmission medium Minimal external components Pair with Holteks 212 series of encoders 18-pin DIP, 20-pin SOP package
Software Tools Keil C compiler Orcad Tool for Circuit Design Flash programmer
Conclusion By application of this project into real time we canavoid malfunctions , Time maintenance system, andlong wait on the Highways can be avoided.
References through Books Council of Europe, “Legal, Operational AndTechnical Standards For E-voting”,Recommendation Rec(2004)1130th of September2004, Council of Europe Publishing, 2004. Federal Election Commission, “Voting SystemStandards.Volume I: Performance Standards”, U.S.Federal Election Commission, 2002.