Basic Arduino (by circuit)

/* Simple LED circuit configuration */

// Turn on and off the LED
const int LED = 13;

void setup() {
  pinMode(LED, OUTPUT);

}

void loop() {
  digitalWrite(LED, HIGH);
  delay(500);
  digitalWrite(LED, LOW);
  delay(500);
}

/* Complex circuit configuration */

// Turn on the entire LED (6)
const unsigned int led_0 = 2;
const unsigned int led_1 = 3;
const unsigned int led_2 = 4;
const unsigned int led_3 = 5;
const unsigned int led_4 = 6;
const unsigned int led_5 = 7;



void setup() {
  // Initialize LED
  pinMode(led_0, OUTPUT);
  pinMode(led_1, OUTPUT);
  pinMode(led_2, OUTPUT);
  pinMode(led_3, OUTPUT);
  pinMode(led_4, OUTPUT);
  pinMode(led_5, OUTPUT);
  

  // Turn on the LED
  digitalWrite(led_0, HIGH);
  digitalWrite(led_1, HIGH);
  digitalWrite(led_2, HIGH);
  digitalWrite(led_3, HIGH);
  digitalWrite(led_4, HIGH);
  digitalWrite(led_5, HIGH);
  
}

void loop() {

}

/* Complex circuit configuration */

// Turn on the entire LED (6) - Iteration Statement(for)
/*
const unsigned int led_0 = 2;
const unsigned int led_1 = 3;
const unsigned int led_2 = 4;
const unsigned int led_3 = 5;
const unsigned int led_4 = 6;
const unsigned int led_5 = 7;
*/

const unsigned int led[8] = {2, 3, 4, 5, 6, 7};

void setup() {
  // Initialize LED
  /*
  pinMode(led_0, OUTPUT);
  pinMode(led_1, OUTPUT);
  pinMode(led_2, OUTPUT);
  pinMode(led_3, OUTPUT);
  pinMode(led_4, OUTPUT);
  pinMode(led_5, OUTPUT);
  */
  int i;
  for (i = 0; i <= 5; i++){
    pinMode(led[i], OUTPUT);
  }
  

  // Turn on the LED
  /*
  digitalWrite(led_0, HIGH);
  digitalWrite(led_1, HIGH);
  digitalWrite(led_2, HIGH);
  digitalWrite(led_3, HIGH);
  digitalWrite(led_4, HIGH);
  digitalWrite(led_5, HIGH);
  */
  for (i = 0; i <= 5; i++){
    digitalWrite(led[i], HIGH);
  }

  
}

void loop() {

}

/* Complex circuit configuration */

// Turn all LEDs on and off in order - Iteration Statement(for)
/*
const unsigned int led_0 = 2;
const unsigned int led_1 = 3;
const unsigned int led_2 = 4;
const unsigned int led_3 = 5;
const unsigned int led_4 = 6;
const unsigned int led_5 = 7;
*/

const unsigned int led[8] = {2, 3, 4, 5, 6, 7};

void setup() {
  // Initialize LED
  /*
  pinMode(led_0, OUTPUT);
  pinMode(led_1, OUTPUT);
  pinMode(led_2, OUTPUT);
  pinMode(led_3, OUTPUT);
  pinMode(led_4, OUTPUT);
  pinMode(led_5, OUTPUT);
  */
  // int i;
  for (int i = 0; i <= 5; i++){
    pinMode(led[i], OUTPUT);
  }
  
}

void loop() {
  // int j;
  for (int i = 0; i <= 5; i++){
    for(int i = 0; i<=5; i++){
      digitalWrite(led[i], LOW);
    }
    digitalWrite(led[i], HIGH);

    delay(500); //  1/4 = 0.25Hz
  }
}

/* Turning the LED dark */

const int LED = 10;

void setup()
{
  analogWrite(LED, 25);
}

void loop(){
  
}

/* Turning the LED bright */

const int LED = 10;

void setup()
{
  analogWrite(LED, 225);
}

void loop(){

}

/* Make the LED Slowly Bright(by analogWrite) */

const int LED = 10;

void setup()
{

}

void loop(){
  int i;
  for (i = 0; i <= 10; i++)
  {
    analogWrite(LED, i*25);
    delay(100);
  }
}

/* LED brightness level 256 adjustment(by analogWrite) */

const int LED = 10;

void setup()
{

}

void loop(){
  int i;
  for (i = 0; i <= 255; i++)
  {
    analogWrite(LED, i);
    delay(4);
  }
}

/* LED brightens up in order */
const unsigned int led[6] = {3, 5, 6, 9, 10, 11};

void setup(){

}


void loop(){
  int i;
  for (i = 0; i <=255; i++){
    analogWrite(led[0], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[1], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[2], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[3], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[4], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[5], i);
    delay(2);
  }


}

/* LED brightens up in order  (iteration statement - for)*/
const unsigned int led[6] = {3, 5, 6, 9, 10, 11};

void setup(){

}


void loop(){
  /*
  int i;
  for (i = 0; i <=255; i++){
    analogWrite(led[0], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[1], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[2], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[3], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[4], i);
    delay(2);
  }

  for (i = 0; i <=255; i++){
    analogWrite(led[5], i);
    delay(2);
  }
  */

  int i;
  int j;

  for (i = 0; i <= 255; i ++)
  {
    for (j = 0; j <= 5; j++){
      analogWrite(led[j], i);
      delay(2);
    }
  }

  for(int k=0; k <= 5; k ++){
    analogWrite(led[k], 0);
  }

  delay(500);

}

/* Brightening and darkening in turn*/
const unsigned int led[6] = {3, 5, 6, 9, 10, 11};

void setup(){

}


void loop(){


  int i;
  int j;

  for (i = 0; i <= 255; i ++)
  {
    for (j = 0; j <= 5; j++){
      analogWrite(led[j], i);
      delay(2);
    }
  }

  for(int k=0; k >= 0; k ++){
    for (int n = 255; n >=0; n--)
    {
      analogWrite(led[k], n);
      delay(2);
    }
    
  }

  delay(500);

}