Arduino practice 3

const int numReadings = 10;

int readings[numReadings];      // the readings from the analog input
int index = 0;                  // the index of the current reading
int total = 0;                  // the running total
int average = 0;                // the average
int brightness = 0;
int fadeAmount = 5;
int delayDuration = 30;
int flag=0;



int inputPin = A0;

void setup()
{
    pinMode(3, OUTPUT);
  // initialize serial communication with computer:
  Serial.begin(9600);                
  // initialize all the readings to 0:
  for (int thisReading = 0; thisReading < numReadings; thisReading++)
    readings[thisReading] = 0;        
}

void loop() {
  // subtract the last reading:
  total= total - readings[index];      
  // read from the sensor:
  readings[index] = analogRead(inputPin);
  // add the reading to the total:
  total= total + readings[index];    
  // advance to the next position in the array:
  index = index + 1;                  

  // if we're at the end of the array...
  if (index >= numReadings)            
    // ...wrap around to the beginning:
    index = 0;                        

  // calculate the average:
  average = total / numReadings;      
  // send it to the computer as ASCII digits
  Serial.println(average);
  delay(1);
  if(average<341) {
  analogWrite(3, brightness);
  if(brightness==0) {
    delayDuration=60;
  }
  if(brightness==255) {
    delayDuration=30;
  }
  brightness = brightness + fadeAmount;
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount ;
 
    if(brightness==0) flag=1;
  }  
  delay(delayDuration);

  }
  else if(average<682){
    analogWrite(3, brightness);

  delayDuration=30;
  brightness = brightness + fadeAmount;
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount ;
    if(brightness==0) flag=1;
  }  
  delay(delayDuration);

  }

  else if(average<1024) {
  analogWrite(3, brightness);
  if(brightness==0) {
    delayDuration=30;
  }
  if(brightness==255) {
    delayDuration=60;
  }
  brightness = brightness + fadeAmount;
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount ;
 
    if(brightness==0) flag=1;
  }  
  delay(delayDuration);

  }
}



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