File content as of revision 0:e6c4994727c2:

#include "mbed.h"
#include <string>

using namespace std;

DigitalOut R1 (D6);
DigitalOut R2 (D7);
DigitalOut R3 (D8);
DigitalOut R4 (D9);

InterruptIn C1 (D10);
DigitalIn C2 (D11);
DigitalIn C3 (D12);

DigitalOut keyled(LED1);
DigitalOut flash(LED4);

AnalogIn ain(PTB0);

Timer t;
float tm ;

char key;
int s=0;

float value_adc =0.0f;
int dig_value = 0;


unsigned char arrkey[12]={ '1' , '2' , '3' ,
                            '4' , '5' , '6' ,
                            '7' , '8' , '9' ,
                            '*' , '0' , '#' };
 
 
void unlock (){
    printf("DOOR UNLOCK: Welcome!\n\r");
}

void lock (){
    printf("DOOR LOCK\n\r");
} 
 
unsigned char char_string[4]= {'*' ,'*' ,'*' ,'*'};
unsigned char password[4]={'1' , '2' , '3' , '4'};
unsigned char passwordA[4]={'4' , '5' , '6' , '7'};
 
unsigned char keypad(){
    unsigned char r,b;
      
    while(1){
        
        for (r=0; r<4; r++){
            b=4;
            R1 = 1; R2 = 1 ; R3 = 1 ; R4 = 1;
            if (r == 0) R1 = 0;
            if (r == 1) R2 = 0;
            if (r == 2) R3 = 0;
            if (r == 3) R4 = 0;
              
            if(C1==0) b=0;
            if(C2==0) b=1;
            if(C3==0) b=2;
             
            if ((!(b==4))){
                key=arrkey[(r*3)+b];
                while(C1==0);
                while(C2==0);
                while(C3==0);
           
                wait(0.2);
            
                char_string[s] = key;
                s++;
                return key;
            }
          
        }
    }
}
 
void handleKeypad (){
    //C1.disable_irq ();
    
    t.start();
    
    int firsttime = 0;
    keyled = 0;
    
    if (firsttime == 0)
            s = -1;
            
    while (1){
       
        //tm = t.read();
        
            key = keypad();

            if (s == 4){
            
                //t.reset();
                firsttime = 1;
                printf("Password: ");  
                for (int i = 0 ; i < 4 ; i++)
                    printf("%c", char_string[i]);
                    printf("\n\r");
                s = 0; 
                
                int j = 0;
                int matchSara = 1;
                while (j < 4){
                    if (char_string [j] == password[j])
                        j++;
                    else{
                        matchSara = 0;
                        break;
                        }       
                }
                
                int k = 0;
                int matchAmir = 1;
                while (k < 4){
                    if (char_string [k] == passwordA[k])
                        k++;
                    else{
                        matchAmir = 0;
                        break;
                        }       
                }
                
                if (matchSara == 1){
                    printf("MATCH Sara\n\r");
                    unlock();
                    t.reset();
                    break;
                }
                else if (matchAmir == 1){
                    printf("MATCH Amir\n\r");
                    unlock();
                    t.reset();
                    break;
                }
                else{
                    printf("WRONG\n\r");
                    printf("lock for wrong password\n\r");
                    t.reset();
                    break;
                    //t.reset();
                }
            
            }
            if (t.read() > 7){ 
                lock();
                t.stop();
                t.reset();
                break;
            } // end timer
        
    } // end while                          
            
}
    

void TestIntrpt(){
     int counter = 0;
     
     t.start();
     
     while (1){
         counter++ ;
         keyled = 1; 
         wait(0.2);
         keyled = 0;
         wait(0.2);
       //  tm = t.read();
         if (t.read() > 5){
            keyled = 1;
            t.stop();
            t.reset();
            C1.enable_irq();
            break;
        }       
     } 
}


int main() {
    
    keyled = 1; 
    C1.fall(&handleKeypad);
    
    while(1) {           // wait around, interrupts will interrupt this!
        
        value_adc = ain.read();
        printf("Analog %5.2f\n\r",value_adc);  
       
        if (value_adc < 0.2){
            printf("Nobody is here!\n\r");
        }
        else {
            printf("Somebody is here!\n\r");
        }
        wait(2);
        //lcd.cls();
        
    }
    
    //TestIntrpt();
    //handleKeypad();
}