Password Security

• Aim: To make a Password Security System using ATmega16 microcontroller, LCD (16x2), Keypad (4x3) and motor.

NOTE: Motor needs L293D IC ( I have not used it for the simulation).

• Code:

#define F_CPU 8000000UL
#include<avr/io.h>
#include<util/delay.h>
void initialize();
void lcd_cmd(char value);
void lcd_data(char value);
void lcd_string(char *str);
void lcd_num(unsigned int number);
void motor();
void initialize()
{
lcd_cmd(0x01); //clear LCD
lcd_cmd(0x02);    //home position
lcd_cmd(0x06);    //L-R
//lcd_cmd(0x04);
lcd_cmd(0x28); //4 bit mode
lcd_cmd(0x0C);    //character generation
}

void lcd_cmd(char value)
{
int un,ln; // pc7-pc4 = un ; pc3-pc4 =ln
un=value&0xF0; // & is anding function
PORTC=0x04|un;
_delay_ms(2);
PORTC=0x00|un;
_delay_ms(2);
ln=(value<<4)&0xF0; //<<=left shif by 4 bits
_delay_ms(2);
PORTC=0x04|ln;
_delay_ms(2);
PORTC=0x00|ln;
}

void lcd_data(char value)
{
int un,ln; // pc7-pc4 = un ; pc3-pc4 =ln
un=value&0xF0; // & is anding function
PORTC=0x05|un;
_delay_ms(2);
PORTC=0x01|un;
_delay_ms(2);
ln=(value<<4)&0xF0; //<<=left shif by 4 bits
_delay_ms(2);
PORTC=0x05|ln;
_delay_ms(2);
PORTC=0x01|ln;
}

void lcd_string(char *str)
{
int i=0;
while(str[i]!='\0')
{
lcd_data(str[i]);
i++;
}
}

void lcd_num(unsigned int number)
{
lcd_cmd(0x04);
int d=0;
while(number!=0)
{
d=number%10;
lcd_data(d+48);
number=number/10;
}
}

void motor(){
DDRA=0xFF;
PORTA=0xFE;

}

int pass=1234;
int ar[4];
void main()
{
DDRC=0xFF;
initialize();
int i=0;
DDRD=0x00;
DDRB=0xFF;

lcd_cmd(0xC0);
lcd_string("Enter Password");

while(1)
{

PORTD=0x0F;
PORTB=0x06;

if(PIND==0x0E)
{
lcd_cmd(0x80+i);
lcd_string("1");
_delay_ms(200);
ar[i]=1;
i++;

}

else if(PIND==0x0D){
lcd_cmd(0x80+i);
lcd_string("4");
_delay_ms(200);
ar[i]=4;

i++;

}

else if(PIND==0x0B){
lcd_cmd(0x80+i);
lcd_string("7");
_delay_ms(200);
ar[i]=7;

i++;

}
else if(PIND==0x07){
lcd_cmd(0x80+i);
lcd_string("*");
_delay_ms(200);
ar[i]=11;

i++;

}

PORTD=0x0F;
PORTB=0x05;

if(PIND==0x0E){
lcd_cmd(0x80+i);
lcd_string("2");
_delay_ms(200);
ar[i]=2;

i++;

}
else if(PIND==0x0D){
lcd_cmd(0x80+i);
lcd_string("5");
_delay_ms(200);
i++;

}

else if(PIND==0x0B){
lcd_cmd(0x80+i);
lcd_string("8");
_delay_ms(200);
ar[i]=8;

i++;

}
else if(PIND==0x07){
lcd_cmd(0x80+i);
lcd_string("0");
_delay_ms(200);
ar[i]=0;

i++;}

PORTD=0x0F;
PORTB=0x03;

if(PIND==0x0E){
lcd_cmd(0x80+i);
lcd_string("3");
_delay_ms(200);
ar[i]=3;

i++;

}
else if(PIND==0x0D){
lcd_cmd(0x80+i);
lcd_string("6");
_delay_ms(200);
ar[i]=6;

i++;

}

else if(PIND==0x0B){
lcd_cmd(0x80+i);
lcd_string("9");
_delay_ms(200);
ar[i]=9;

i++;

}
else if(PIND==0x07){
if(ar[0]==1 && ar[1] ==2 && ar[2]==3 && ar[3]==4){
lcd_data(0x00);
lcd_cmd(0xC0);
lcd_string("password correct");
motor();

}
else {
lcd_cmd(0xC0);
lcd_string("Pass incorrect");
}

}


}
}

• Hardware information: 

Port B and D= Keypad
PortC = LCD display
Port A= Motor
Password set: 1234

• Proteus Simulation:

Password security Simulation

•  Constraints: 

1) To reset, Close the program and the restart.

2)Motor needs external Power
3) Password can't be reset externally

• Conclusion: 

Password Security Systems has been created using C programming in Avr studio software and simulation of the same in proteus software. The simulation picture is shown above and the constraints have been noted.