มีใครพอเขียน Flowchart Diagram เป็นมั่งใหมครับ ผมมี code อยู่อะครับ

//Keypad connection: 
#define row0 PIN_B4 
#define row1 PIN_B5 
#define row2 PIN_B6 
#define row3 PIN_B7 
#define col0 PIN_B0 
#define col1 PIN_B1 
#define col2 PIN_B2 
#define col3 PIN_B3 

// Keypad layout: 
char const KEYS[4][4] = 
{{'1','2','3','A'}, 
 {'4','5','6','B'}, 
 {'7','8','9','C'}, 
 {'*','0','D','#'}}; 


#define KBD_DEBOUNCE_FACTOR 33 // Set this number to apx n/333 where 
// n is the number of times you expect 
// to call kbd_getc each second 

void kbd_init() 
  { 
	//set_tris_b(0xF0); 
 	//output_b(0xF0); 
	port_b_pullups(true);  
  } 

short int ALL_ROWS (void) 
   { 
	if(input (row0) & input (row1) & input (row2) & input (row3)) 
   		return (0); 
	else 
   		return (1); 
   } 



char kbd_getc() 
{ 
	static byte kbd_call_count; 
	static short int kbd_down; 
	static char last_key; 
	static byte col; 

	byte kchar; 
	byte row; 

	kchar='\0'; 

	if(++kbd_call_count>KBD_DEBOUNCE_FACTOR) 
  	{ 
   		switch (col) 
     		{ 
      			case 0: 
        		  output_low(col0); 
        		  output_high(col1); 
        		  output_high(col2); 
       			  output_high(col3); 
        		  break; 
    
      			case 1: 
        		  output_high(col0); 
        		  output_low(col1); 
        		  output_high(col2); 
        		  output_high(col3); 
        		  break; 

     			case 2: 
        		  output_high(col0); 
        		  output_high(col1); 
        		  output_low(col2); 
        		  output_high(col3); 
        		  break; 

      			case 3: 
        		  output_high(col0); 
        		  output_high(col1); 
        		  output_high(col2); 
        		  output_low(col3); 
        		  break; 
      		} 

   	if(kbd_down) 
     		{ 
      			if(!ALL_ROWS()) 
        		{ 
         		  kbd_down=false; 
         		  kchar=last_key; 
         		  last_key='\0'; 
        		} 
     		} 
   			else 
     			{ 
      			  if(ALL_ROWS()) 
        		  { 
         		    if(!input (row0)) 
            			row=0; 
         		    else if(!input (row1)) 
            			row=1; 
         		    else if(!input (row2)) 
           			 row=2; 
         		    else if(!input (row3)) 
            			row=3; 

         		    last_key =KEYS[row][col]; 
         		    kbd_down = true; 
        		  } 
      			  else 
        		  { 
         			++col; 
         		   	if(col==4) 
            			col=0; 
        		   } 
     		} 
   	kbd_call_count=0; 
  	} 
     return(kchar); 
}