/*
  Two Tones at once test.

  https://www.arduino.cc/en/Tutorial/BuiltInExamples/BlinkWithoutDelay
*/

// constants won't change. Used here to set a pin number:
const int piezoPinOne = LED_BUILTIN;  // the number of the LED pin
const int piezoPinTwo = 12;

// Variables will change:
int ledState = LOW;  // ledState used to set the LED

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMicros = 0;  // will store last time LED was updated

// constants won't change:
const long interval = 10;  // interval at which to blink (microseconds)
//10 microseconds see: https://www.arduino.cc/reference/en/language/functions/time/micros/ 
// accuracy 4-8 depending on board.


void setup() {
  // set the digital pin as output:
  pinMode(piezoPinOne, OUTPUT);
  pinMode(piezoPinTwo, OUTPUT);
}

void loop() {
  // here is where you'd put code that needs to be running all the time.

  // check to see if it's time to blink the LED; that is, if the difference
  // between the current time and last time you blinked the LED is bigger than
  // the interval at which you want to blink the LED.
  unsigned long currentMicros= micros();

  if (currentMicros - previousMicros >= interval) {
    // save the last time you blinked the LED
    previousMicros = currentMicros;

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW) {
      ledState = HIGH;
      noTone(piezoPinOne);
      tone(piezoPinOne, 200);
      
    } else {
      ledState = LOW;
      noTone(piezoPinTwo);
      tone(piezoPinTwo, 400);
    }

    // set the LED with the ledState of the variable:
    
  }
}