PWM ajustavel

//http://labdegaragem.com/forum/topics/convertendo-valores-e-jogando-no-lcd
  #include <LiquidCrystal.h>
  #include <TimerOne.h>
  #define botao_incremento A0
  #define botao_decremento A1
  #define botao_frequencia_incremento A2
  #define botao_frequencia_decremento A3
  unsigned long freq;
  float dspduty;
  unsigned int duty;
  LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
// ------------------------------------ setup -------------------------------
  void setup()
  {
    Serial.begin(9600);
    lcd.begin(16,2);
    lcd.print("BEM VINDOS");
    pinMode(A0, INPUT);
    pinMode(A1, INPUT);
    pinMode(A2, INPUT);
    pinMode(A3, INPUT);
    pinMode(9, OUTPUT);
  }
// ---------------------------------- map floating ------------------------
float map_double(double x, double in_min, double in_max, double out_min, double out_max)
{
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}
// ------------------------------------ loop -------------------------------
  void loop()
  {

    lcd.print ("  ");
    lcd.setCursor(0,1);
    Timer1.initialize(freq);
    Timer1.pwm(9, duty);
    delay(100);
    if(digitalRead(botao_frequencia_incremento) == HIGH)
    {
       freq = freq +1000;
//       Serial.println(freq);
       delay(500);
    }
    if(digitalRead(botao_frequencia_decremento)== HIGH)
    {
       freq = freq -1000;
  //     Serial.println(freq);
       delay(500);
    }
    lcd.print ("  ");
    lcd.setCursor(0,1);
    if(digitalRead(botao_incremento) == HIGH)
    {
      duty = duty +500;
      delay(500);
    }
    if(digitalRead(botao_decremento) == HIGH)
    {
      duty = duty -500;
      delay(500);
    }
//          Serial.println(duty);
//    dspduty = map(duty,0 ,1023,0, 100);
    dspduty = map_double(duty,0 ,1023,0, 100);
          Serial.println(dspduty,1);
    lcd.print(dspduty);
  }