All Hands Active! ATMegaZero Workshop with ishotjr Learning Shield Demo

ATMegaZero_LS_Demo.ino

/*
 * ATMegaZero Learning Shield Demo
 * for the All Hands Active! ATMegaZero Workshop with ishotjr
 * https://www.meetup.com/AllHandsActive/events/276805820/
 * 
 * You can purchase the ATMegaZero Learning Shield from the ATMegaZero Online Store at:
 * https://shop.atmegazero.com/products/atmegazero-learning-shield
 * 
 * For full documentation please visit https://atmegazero.com
 */

// Learning Shield pins
const int BUZZER_PIN = 6;
const int GREEN_LED_PIN = A2;
const int YELLOW_LED_PIN = A1;
const int RED_LED_PIN = A0;
const int BUTTON_PIN = 7;

// button state variables
int lastState = HIGH;
int currentState;

// this function runs once when the board powers on
void setup() {
  // set up pin modes
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(YELLOW_LED_PIN, OUTPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  
  // turn all LEDs ON
  digitalWrite(GREEN_LED_PIN, HIGH);
  digitalWrite(YELLOW_LED_PIN, HIGH);
  digitalWrite(RED_LED_PIN, HIGH);
  
  // quick buzzer sweep
  for (int note = 440; note <= 880; note += 20) {
    // you can either use the third parameter or a delay to persist the tone
    tone(BUZZER_PIN, note);   //, 1000 / 10);
    delay(100);
  }
  // silence please
  noTone(BUZZER_PIN);
}

// after setup, this function runs over and over as long as the board has power
void loop() {
  // read button state (high = pressed)
  int currentState = digitalRead(BUTTON_PIN);

  // if the button was not pressed, but is now
  // *no debounce
  if (lastState == LOW && currentState == HIGH) {
    blink_em();
  }

  // save the current state for next time
  lastState = currentState;
}

// this is a user-defined function that runs on button press
void blink_em() {

  // turn all LEDs OFF, buzzer ON!
  // 440 is an easy-to-remember Hz value corresponding to A above middle C
  // 220 is A one octave down; 880 is A one octave up
  tone(BUZZER_PIN, 220);
  digitalWrite(GREEN_LED_PIN, LOW);
  digitalWrite(YELLOW_LED_PIN, LOW);
  digitalWrite(RED_LED_PIN, LOW);
  
  // wait 1 second (total)
  delay(900);
  noTone(BUZZER_PIN);
  delay(100);
  
  // turn just red LED ON, buzzer ON!
  tone(BUZZER_PIN, 220);
  digitalWrite(GREEN_LED_PIN, LOW);
  digitalWrite(YELLOW_LED_PIN, LOW);
  digitalWrite(RED_LED_PIN, HIGH);

  // wait 1 second (total)
  delay(900);
  noTone(BUZZER_PIN);
  delay(100);

  // turn yellow LED ON, buzzer ON!
  tone(BUZZER_PIN, 220);
  digitalWrite(YELLOW_LED_PIN, HIGH);
  
  // wait 1 second (total)
  delay(900);
  noTone(BUZZER_PIN);
  delay(100);
  
  // turn green LED ON, others OFF, buzzer ON!
  tone(BUZZER_PIN, 880, 1500);  // note 3rd parameter vs. delay()
  digitalWrite(GREEN_LED_PIN, HIGH);
  digitalWrite(YELLOW_LED_PIN, LOW);
  digitalWrite(RED_LED_PIN, LOW);

  // note that we are repeating ourselves above with slightly different parameters;
  // we could be more "DRY" and refactor to abstract these repetitions into their
  // own function and just call it with the differing parameters
}