BLOCK DIADRAM DESCRIPTION
FINGERPRINT SENSOR
Here we are using a fingerprint module named R303A to receive the thumb impressions of each voters. When the voter place his/her finger on the sensor, the sensor will read the thumb impression and handover them to a SCU ( signal conditioning unit). The out put of this sensor will be voltage levels in the form of pulses which are after passing through a SCU will store on the EEPROM.
SCU (SIGNAL CONDITIONING UNIT)
A SCU is used to convert the received signal into binary codes. Here the output of the FPS, in the form of pulses, is feed to the SCU and after converting them to binary codes it is given to the MC and MC will execute the specified programs.
KEYPAD
A numeric keypad, or numpad for short, is the small, palm-sized, seventeen key section of a computer keyboard, usually on the very far right. The numeric keypad features digits 0 to 9, addition (+), subtraction (-), multiplication (*) and division (/) symbols, a decimal point (.) and Num Lock and Enter keys. Laptop keyboards often do not have a numpad, but may provide numpad input by holding a modifier key (typically lapelled "Fn") and operating keys on the standard keyboard.
It is used for voting and also at the control key panel. A voting is accomplish only by pressing the switch corresponding to the candidate.
16X2 LCD DISPLAY
A 16x2 LCD display is interfaced with the MCU in order to provide instructions to the voter. LCD stands for Liquid Crystal Display. The most commonly used LCDs found in the market today are 1 Line, 2 Line or 4 Line LCDs which have only 1 controller and support at most of 80characters.
MICROCONTROLLER
Microcontrollers are destined to play an increasingly important role in revolutionizing various industries and influencing our day to day life more strongly than one can imagine. This unit controls all the functions of other blocks explained here. MCU takes or read data from the sensor and controls all the functions of the whole system by manipulating these data.
Here the popular microcontroller AT89C51 from MICROCHIP corporation is used as the CPU of the system. This is a popular 8 bit microcontroller in the world. They are available in wide variety in pin outs, memory capacity and have lots of integrated peripherals like ADCs, SERIAL and EEPROM.
EEPROM
EEPROM (also written E2PROM and pronounced "e-e-prom," "double-e prom," "e-squared," or simply "e-prom") stands for Electrically Erasable Programmable Read-Only Memory and is a type of non volatile memory used in computers and other electronic devices to store small amounts of data that must be saved when power is removed.
EEPROM is interfaced with the MCU that can act as a database to store the thumb impressions of the voter.
LED
LED is used for visual indications.
A light emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices, and are increasingly used for lighting. It is introduced as a practical electronic component in 1962, early LEDs emitted low intensity red light, but modern versions are available across the visible, ultraviolet and infrared wavelengths, with very high brightness.