int led = 9; //Set LED in Pin 9
int cycleDir, dutyCycle; //cycleDir for increment/decrement, dutyCycle as integer input

// Function to set PWM duty cycle
void setPWMDutyCycle(int pin, int dutyValue) {
  // Map the duty cycle percentage (0-100) to a value (0-255) for analogWrite
  int pwmValue = map(dutyValue, 0, 100, 0, 255);
  // Set the PWM signal on the specified pin
  analogWrite(pin, pwmValue);
}

void setup() {
  // Set the pin mode for PWM output
  pinMode(led, OUTPUT);
}

void loop() {
/*****For dummy only, set value 0 to 100 then back to 0******/
  if(dutyCycle == 0)
  {
    cycleDir = 1;
  }
  else if(dutyCycle >= 100)
  {
    dutyCycle = 100; // To make sure that the duty cycle is between 0 and 100
    cycleDir = 0;
  }
  if(cycleDir == 1)
    dutyCycle += 5;
  else
    dutyCycle-= 5;
  /************************************************/
  setPWMDutyCycle(led, dutyCycle); // Set int duty cycle for LED pin
  delay(100); // Wait for 0.1 second
}