• // LED Mode Selection

• void setMode(int mode) {

• //RED

• if (mode == 1) {

• digitalWrite(RLED, HIGH);

• digitalWrite(GLED, LOW);

• digitalWrite(BLED, LOW);

• }

• //GREEN

• else if (mode == 2) {

• digitalWrite(RLED, LOW);

• digitalWrite(GLED, HIGH);

• digitalWrite(BLED, LOW);

• }

• //BLUE

• else if (mode == 3) {

• digitalWrite(RLED, LOW);

• digitalWrite(GLED, LOW);

• digitalWrite(BLED, HIGH);

• }

• //PURPLE (RED+BLUE)

• else if (mode == 4) {

• analogWrite(RLED, 127);

• analogWrite(GLED, 0);

• analogWrite(BLED, 127);

• }

• //TEAL (BLUE+GREEN)

• else if (mode == 5) {

• analogWrite(RLED, 0);

• analogWrite(GLED, 127);

• analogWrite(BLED, 127);

• }

• //ORANGE (GREEN+RED)

• else if (mode == 6) {

• analogWrite(RLED, 127);

• analogWrite(GLED, 127);

• analogWrite(BLED, 0);

• }

• //WHITE (GREEN+RED+BLUE)

• else if (mode == 7) {

• analogWrite(RLED, 170);

• analogWrite(GLED, 170);

• analogWrite(BLED, 170);

• }

• //OFF (mode = 0)

• else {

• digitalWrite(RLED, LOW);

• digitalWrite(GLED, LOW);

• digitalWrite(BLED, LOW);

• }

• }

•

• void setup() {

• // For 1st Arduino Interaction

• pinMode(BUTTON1, INPUT);

• pinMode(LED1, OUTPUT);

•

• // For 2nd Arduino Interaction

• pinMode(BUTTON2, INPUT);

• pinMode(LED2, OUTPUT);

•

• // For 3rd Arduino Interaction

• pinMode(BUTTON3, INPUT); // Set button as input

• pinMode(BLED, OUTPUT); // Set Blue LED as Output

• pinMode(GLED, OUTPUT); // Set Green LED as Output

• pinMode(RLED, OUTPUT); // Set Red LED as Output

•

• // For 4th Arduino Interaction (Melody)

• pinMode(BUTTON4, INPUT);

• lastButton4 = LOW;

•

• // Check if the button is pressed during setup and start playing the melody

• boolean currentButton4 = digitalRead(BUTTON4);

• if (currentButton4 == HIGH && lastButton4 == LOW) {

• // Button is pressed

• // Start playing the melody

• for (int i = 0; i < sizeof(notes) / sizeof(notes[0]); i++) {

• tone(SPEAKER, notes[i], times[i]);

• delay(times[i]);

• }

• }

• lastButton4 = currentButton4;

• }

•

• void loop() {

• unsigned long melodyStartTime = 0; // Declare melodyStartTime

• int melodyIndex = 0; // Declare melodyIndex

•

• // For 1st Arduino Interaction

• boolean currentButton1 = debounceButton(BUTTON1, lastButton1);

• if (lastButton1 == LOW && currentButton1 == HIGH) {

• if (millis() - lastDebounceTime > debounceDelay) {

• lastDebounceTime = millis();

• led1On = !led1On;

• digitalWrite(LED1, led1On);

• }

• }

• lastButton1 = currentButton1;

•

• // For 2nd Arduino Interaction

• boolean currentButton2 = debounceButton(BUTTON2, lastButton2);

 if (lastButton2 == LOW && currentButton2 == HIGH) {

• led2On = !led2On;

• }

•

• if (led2On) {

• val = analogRead(LIGHT);

• val = map(val, MIN_LIGHT, MAX_LIGHT, 255, 0);

• val = constrain(val, 0, 255);

• analogWrite(LED2, val);

• } else {

• analogWrite(LED2, 0);

• }

•

• lastButton2 = currentButton2;

•

• // For 3rd Arduino Interaction

• boolean currentButton3 = debounceButton(BUTTON3, lastButton3);

• if (lastButton3 == LOW && currentButton3 == HIGH) {

• if (millis() - lastDebounceTime > debounceDelay) {

• lastDebounceTime = millis();

• ledMode = (ledMode + 1) % 8;

• setMode(ledMode);

• }

• }

• lastButton3 = currentButton3;

•

• // For 4th Arduino Interaction (Melody)

• boolean currentButton4 = digitalRead(BUTTON4);

• if (currentButton4 == HIGH && lastButton4 == LOW) {

• // Reset button is pressed, play the melody again

• for (int i = 0; i < sizeof(notes) / sizeof(notes[0]); i++) {

• tone(SPEAKER, notes[i], times[i]);

• delay(times[i]);

• }

• }

•

• lastButton4 = currentButton4;

• }

•

• boolean debounceButton(int buttonPin, boolean last) {

• boolean current = digitalRead(buttonPin);

• if (last != current) {

• delay(5);

• current = digitalRead(buttonPin);

• }

• return current;

• }