long currentTime = 0;
long lastLED2Time = 0;
long lastLED3Time = 0;
long lastLED4Time = 0;
long lastLED5Time = 0;
hw_timer_t *timer1000ms = NULL;
void ARDUINO_ISR_ATTR isrTimer1000ms() {
  digitalWrite(2, !digitalRead(2));
}
void setup() {
  Serial.begin(115200);
  Serial.println("Start!");
  //LED pin
  pinMode(2, OUTPUT);         // LED1
  pinMode(16, OUTPUT);        // LED2
  pinMode(17, OUTPUT);        // LED3
  pinMode(18, OUTPUT);        // LED4
  pinMode(19, OUTPUT);        // LED5
  timer1000ms = timerBegin(1000000);
  timerAttachInterrupt(timer1000ms, &isrTimer1000ms);
  timerAlarm(timer1000ms, 1000000, true, 0); // 1M=1s, 1s=1,000,000
}
void loop() {
  currentTime = millis();
  //  LED2 0.1 seconds
  if (currentTime - lastLED2Time >= 100) {
    lastLED2Time = currentTime;
    digitalWrite(16, !digitalRead(16));  // Toggle LED
  }
  //  LED3 0.5 seconds
  if (currentTime - lastLED3Time >= 500) {
    lastLED3Time = currentTime;
    digitalWrite(17, !digitalRead(17));  // Toggle LED
  }
  // LED4 1.5 seconds
  if (currentTime - lastLED4Time >= 1500) {
    lastLED4Time = currentTime;
    digitalWrite(18, !digitalRead(18));  // Toggle LED
  }
  // LED5 3 seconds
  if (currentTime - lastLED5Time >= 3000) {
    lastLED5Time = currentTime;
    digitalWrite(19, !digitalRead(19));  // Toggle LED
  }
}