WEEK 4

CHAPTER 3 

METHODOLOGY

  

3.1              Introduction

The methodology part is used to define about how the project should be designed based on a few requirements and function of the component in the circuit. The system will be divide with 2 common parts consists of combination between hardware and software development.

I-key for vehicle is the project to upgrade conventional key with new system. In this project, there have two parts which are hardware part and software part. The device has three main segments which are input segment, processing segment, and output segment. In the input segment, the fingerprint reader is to identify the data.  In the processing segment, the microcontroller is used to process the input signal and send to the output segment. In the output segment, there have two components which are starter motor and the LED indicator. In the software part, the programming is design according to the device’s operation. The language that has been used is depending on the type of microcontroller. 

The block diagram above show how this system operates. Fingerprint reader is used as input to identify the data given. So the data will be read by microcontroller and delivered to starter motor. LCD just to show that the system in running condition. Push button key will be used if vehicle need to service at workshop. The owner can choose the mode to deactivate thumbprint system, and key can be used as usual. The DC motor will run and stop according to the signal that given by mircocontoller.

3.1              Hardware Development

3.1.1        UART Fingerprint Reader

Item Description:

·         Sensor CAMA optical sensor CMOS

·         Glass material  K9

·         Scan area 18mm*20mm

·         Fingerprint image        210 x 250 (pixel)

·         Resolution       500 DPI

·         Fingerprint template    496tes

·         Communication port   UART

·         FRR    < 0.1%

·         FAR    < 0.001%

·         Identification speed    1:1 <0.5S; 1:N (2000 fingerprints) <0.9S

·         Fingerprint capacity    3000

·         Work current   < 100mA

·         Standby current          < 20μA

·         Power supply  DC 3.3V

·         Working temperature  -10°C- 60°C

·         Working humidity       20%– 80%

·         Dimensions     58*23*22mm

UART fingerprint reader used as an input. It’s can save the data and transfer into microcontroller. This fingerprint reader ability is low power consumption, small size and excellent performance.

3.3.2    PIC16F877A

A PIC microcontroller is a single integrated circuit small enough to fit in the palm of a hand. ‘Traditional’ microprocessor circuits contain four or five separate integrated circuits such as microprocessor (CPU) itself, an EPROM program memory chip, some RAM memory and an input/output interface. With PIC microcontrollers all these functions are included within one single package, making them cost effective and easy to use. 

PIC microcontrollers can be used as the ‘brain’ to control a large variety of products. In order to control devices, it is necessary to interface (or ‘connect’) them to the PIC microcontroller. One of the main advantages dealing with PIC Microcontroller is the large database of information and technical support from the internet. The PIC family is a small microcontroller designed for fast input/output control using a small instruction set.

The PIC is a low-cost microcontroller and can be reprogrammed thousands of times again and again using Flash programmable EEPROM using just electronic signals from a PC like a higher-level microcontroller such as BASIC stamps. The PIC Microcontroller is able to store and run unique programs and can be programmed to perform functions based on predetermined situations (1/O-line logic) and selections.

There are 40 pins on PIC16F877A. Most of them can be used as an IO pin. Others are already for specific functions. These are the pin functions:

1.         MCLR - to reset the PIC                    21.       RD2 - port D pin 2

2.         RA0 - port A pin 0                              22.       RD3 - port D pin 3

3.         RA1 - port A pin 1                              23.       RC4 - port C pin 4

4.         RA2 - port A pin 2                              24.       RC5 - port C pin 5

5.         RA3 - port A pin 3                              25.       RC6 - port C pin 6

6.         RA4 - port A pin 4                              26.       RC7 - port C pin 7

7.         RA5 - port A pin 5                              27.       RD4 - port D pin 4

8.         RE0 - port E pin 0                               28.       RD5 - port D pin 5

9.         RE1 - port E pin 1                               29.       RD6 - port D pin 6

10.       RE2 - port E pin 2                               30.       RD7 - port D pin 7

11.       VDD - power supply                          31.       VSS     -ground

12.       VSS - ground                                      32.       VDD - power supply

13.       OSC1 - connect to oscillator               33.       RB0 - port B pin 0

14.       OSC2 - connect to oscillator               34.       RB1 - port B pin 1

15.       RC0 - port C pin 0                              35.       RB2 - port B pin 2

16.       RC1 - port C pin 0                              36.       RB3 - port B pin 3

17.       RC2 - port C pin 0                              37.       RB4 - port B pin 4

18.       RC3 - port C pin 0                              38.       RB5 - port B pin 5

19.       RD0 - port D pin 0                              39.       RB6 - port B pin 6

20.       RD1 - port D pin 1                              40.       RB7 - port B pin 7

3.1.1        LCD Screen Display

A liquid crystal display (LCD) is a thin, flat electronic visual display that uses the light modulating properties of liquid crystals (LCs). LCs does not emit light directly. They are used in a wide range of applications, including computer monitors, television, instrument panels, aircraft cockpit displays, signage, etc. They are common in consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones. LCDs have displaced cathode ray tube (CRT) displays in most applications. They are usually more compact, lightweight, portable, less expensive, more reliable, and easier on the eyes.

A character LCD is display device designed for interfacing with embedded systems. These screens come in common configurations of 8x1, 16x2, 20x4, and so on. The character LCD can come with or without backlights, which may be LED, fluorescent, or electroluminescent. Character LCDs use a standard 14 pin interface. If the screen has a backlight, it will have 16 pins.

           

The backlight power rail differs often, the polarity can be different and some screens need an external resistor. Usually the supply voltage is 5V DC. Character LCDs can operate in 4-bit or 8-bit mode. In 4-bit mode, pins 7 through 10 are unused and the entire byte is sent to the screen using pins 11 through 14 by sending 4-bits (nibble) at a time.

3.3.4DC Motor

A DC motor is an electric motor that runs on direct current (DC) electricity. DC motors were used to run machinery, often eliminating the need for a local steam engine or internal combustion engine. DC motors can operate directly from rechargeable batteries, providing the motive power for the first electric vehicles. For this project, the DC motor is used as outputs that represent the real vehicle engine.

3.4              Software Development

3.4.1        Flowchart of Operation

This I-Key for Vehicle project has three (3) modes for start the motor. This system has three(3) modes that can be choose by owner for start the vehicle. Mode 1is by using the key for start the vehicle. Mode 2 is by using fingerprint and for the mode 3 that are using both key and fingerprint to start the vehicle. Fingerprint can save up to 10 different data. The LCD will display the mode and motor will function.

Press the selected button to choose the mode. If mode 1 is selected, just press the push button key to start and stop the vehicle. For using mode 2 and mode 3, the data must be save first. To save the data into the memory system, press Enroll button and place the fingerprint at fingerprint reader. The buzzer will beep once and the LCD will display Id 1 for the first data. After the data have been saving, the vehicle can be start by placing the fingerprint. To add the data, press Enroll button and place the fingerprint. Then LCD will show Id 2, means the second person also can start the vehicle. To stop the vehicle just put any fingerprints that have been saving into the data. The vehicle can be start and stop just by the saving fingerprint data. Mode 3 used both systems to start and stop the vehicle, key and fingerprint. Place the fingerprint at scanner first then press the push button key to start the vehicle. To stop the vehicle engine, place the fingerprint at scanner and press push button key again. Then the system will stop the vehicle engine.

To delete the data one by one, press delete button then LCD will display Delete? word. If agree to delete, place the fingerprint at fingerprint reader the buzzer will beep once and LCD will display delete Id 1. For delete all the data, press reset button and press enroll button for 5 second. The LCD will display delete all users and all the data will be removed from the system.