#define SEG_A   9  
#define SEG_B   10 
#define SEG_C   2  
#define SEG_D   3  
#define SEG_E   4  
#define SEG_F   5  
#define SEG_G   6  
#define PD      7  

char caractere = 0;
byte segmentos[16] = { 0b11000000,
           0b11111001,           
           0b10100100,           
           0b10110000,           
           0b10011001,           
           0b10010010,           
           0b10000010,           
           0b11111000,           
           0b10000000,           
           0b10010000,           
           0b10001000,           
           0b10000011,           
           0b10100111,           
           0b10100001,           
           0b10000110,           
           0b10001110 
           };

void display_7seg( byte display_seg )
{
  digitalWrite(SEG_A, bitRead(display_seg, 0));  
  digitalWrite(SEG_B, bitRead(display_seg, 1));  
  digitalWrite(SEG_C, bitRead(display_seg, 2));  
  digitalWrite(SEG_D, bitRead(display_seg, 3));  
  digitalWrite(SEG_E, bitRead(display_seg, 4));  
  digitalWrite(SEG_F, bitRead(display_seg, 5));  
  digitalWrite(SEG_G, bitRead(display_seg, 6));  
  digitalWrite(PD, bitRead(display_seg, 7));
}

void setup()
{
  pinMode(SEG_A, OUTPUT); 
  pinMode(SEG_B, OUTPUT);
  pinMode(SEG_C, OUTPUT);
  pinMode(SEG_D, OUTPUT);
  pinMode(SEG_E, OUTPUT);
  pinMode(SEG_F, OUTPUT);
  pinMode(SEG_G, OUTPUT);
  pinMode(PD, OUTPUT);

  Serial.begin(9600);

  display_7seg( 0b11111111 ); }

void loop()
{
  if(Serial.available() > 0)
  {
    caractere = Serial.read();
    
    if( ( caractere >= '0' ) && ( caractere <= '9' ) )      
    {    
      display_7seg( segmentos[caractere - '0'] );               }
    else if( ( caractere >= 'a' ) && ( caractere <= 'f' ) )  
    {    
      display_7seg( segmentos[caractere - 87] );               }
    else if( ( caractere >= 'A' ) && ( caractere <= 'F' ) )  
    {    
      display_7seg( segmentos[caractere - 55] );               }
    else
    {
      display_7seg( 0b11111111 );
    }
    Serial.println( caractere );
  }
}