#include "mbed.h"
#include "TextLCD.h"

TextLCD lcd(D8,D9,D10,D11,D12,D13);

BusOut sigout(D0,D1,D2,D3);//scan lines
BusIn sigin(D4,D5,D6,D7);//return lines

BusOut Lcd_pins(D8,D9,D10,D11,D12,D13);

int read;

int main()
{
    sigin.mode(PullDown);
    
    sigout=0xF;
    while(sigin!=0);
    
    while(1)
    {
        sigout=0xF;
        while(sigin==0);
        
        sigout=0x1;
        if((sigin&0x1)==0x1)
        {
            while((sigin&0x1)==0x1)
            {
                read=0;
            }
         }
         
         else if((sigin&0x2)==0x2)
         {
           while((sigin&0x2)==0x2) 
           {
                read=4;
            }
         }
         
         else if((sigin&0x4)==0x4)
         {
           while((sigin&0x4)==0x4) 
           {
                read=8;
            }
         } 
         
         else if((sigin&0x8)==0x8)
         {
           while((sigin&0x8)==0x8) 
           {
                read=12;
            }
         } 
         
         else
         {
              sigout=0x2;
              if((sigin&0x1)==0x1)
              {
                  while((sigin&0x1)==0x1) 
                 {
                  read=1;
                 }
              }
              
         else if((sigin&0x2)==0x2)
         {
           while((sigin&0x2)==0x2) 
           {
                read=5;
            }
         } 
         
         else if((sigin&0x4)==0x4)
         {
           while((sigin&0x4)==0x4) 
           {
                read=9;
            }
         } 
         
         else if((sigin&0x8)==0x8)
         {
           while((sigin&0x8)==0x8) 
           {
                read=13;
            }
         }
         
         else
         {
              sigout=0x4;
              if((sigin&0x1)==0x1)
              {
                  while((sigin&0x1)==0x1) 
                 {
                  read=2;
                 }
              }
              
              else if((sigin&0x2)==0x2)
              {
                while((sigin&0x2)==0x2) 
                 {    
                   read=6;
                 }
              }
              
              else if((sigin&0x4)==0x4)
              {
                while((sigin&0x4)==0x4) 
                 {    
                   read=10;
                 }
              }
              
              else if((sigin&0x8)==0x8)
              {
                while((sigin&0x8)==0x8) 
                 {    
                   read=14;
                 }
              }
              
              
              else
           {
              sigout=0x8;
              if((sigin&0x1)==0x1)
              {
                  while((sigin&0x1)==0x1) 
                 {
                  read=3;
                 }
            }
            
            else if((sigin&0x2)==0x2)
              {
                while((sigin&0x2)==0x2) 
                 {    
                   read=7;
                 }
              }
              
              else if((sigin&0x4)==0x4)
              {
                while((sigin&0x4)==0x4) 
                 {    
                   read=11;
                 }
              }
              
              else if((sigin&0x8)==0x8)
              {
                while((sigin&0x8)==0x8) 
                 {    
                   read=15;
                 }
              }
            
            else
            {
                read=0;
            }
            
           }
          }
         }
        }
        Lcd_pins=read;
        }
       }  
      }