// LECTURE 08 WHAT DOES THIS CODE DO PB NEWTONE LED BUZZER INTERRUPT

#include <TimerOne.h>
#include <NewTone.h>

const byte LED = 3;  // LED
const byte PB = 2;   // PUSHBUTTON
const byte PIEZO = 7; // PASSIVE BUZZER
volatile bool state = HIGH;
volatile unsigned long futureTime = millis();

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(PB, INPUT_PULLUP);
  pinMode(PIEZO, OUTPUT);

  attachInterrupt(digitalPinToInterrupt(PB), pinISR, CHANGE);
  Timer1.initialize(5000000);    // 5 seconds on 5 seconds off
  Timer1.attachInterrupt(timerISR);
}
void loop() {
}
void timerISR() {
  state = ! state;
  digitalWrite(LED, state);
}
void pinISR() {
  if (millis() > futureTime) {
    NewTone(PIEZO, 1000, 500);    //  1000 hz every 500 millisec
    futureTime = millis() + 500;   // o.5 second tone
  }
}