Blink LED with different on off times just once with millis

Question

So Im having trouble trying to figure this out. My project needs a valve to stay shut and when an event is triggered, 3 seconds into that event the valve opens for 2 seconds, then remain shut till it's triggered again. I was just treating it like an LED in the code. I was trying to code it to jump from one if-statement to the next with the appropriate delays but it doesn't work the way i thought it would. Any help would be great. Thanks

//the event does ventGo0 = true;
if(((millis() - previousVenting) > offoffDuration)&&(ventGo0==true)){ 
        previousVenting1 = millis();
        ventGo1=true;
        ventGo0=false;
       }
 if(((millis() - previousVenting1) &gt; onDuration)&amp;&amp;(ventGo1==true)){ 
   digitalWrite(ventPin, HIGH);
   previousVenting2 = millis();
   ventGo2=true;
   ventGo1=false;
 }



   if(((millis() - previousVenting2) &gt; offDuration)&amp;&amp;(ventGo2==true)){  
     digitalWrite(ventPin, LOW);
     ventGo2=false;
   }

  ```

just a note ... if (ventGo1==true) is same as if (ventGo1) — jsotola, May 08 '21 at 20:55

VE7JRO · Accepted Answer · 2021-05-08T21:53:26.227

You could use two millis() based timers.

// Sketch uses 1066 bytes (3%) of program storage space.
// Global variables use 27 bytes (1%) of dynamic memory.
// Arduino Uno, IDE 1.8.9
class MillisTimer{
private:
unsigned long m_timeInMilliSeconds;
unsigned long m_previousMillis;
byte m_timerActive;


public:
MillisTimer(unsigned long timeInMilliSeconds):
  m_timeInMilliSeconds(timeInMilliSeconds){
  m_timerActive = 0;
  m_previousMillis = 0;
}

bool Update(){
  if(m_timerActive &amp;&amp; (millis() - m_previousMillis &gt;= m_timeInMilliSeconds)){
    m_previousMillis += m_timeInMilliSeconds;
    return 1;
  }
  else{
    return 0;
  }
}

void Start(){
  m_timerActive = 1;
}

void Stop(){
  m_timerActive = 0;
}

void ReStart(){
  m_timerActive = 1;
  m_previousMillis = millis();
}

byte IsActive(){
  return m_timerActive;
}


};
// Make copies of the object to work with.
MillisTimer TwoSecondTimer(2000);
MillisTimer ThreeSecondTimer(3000);
void setup(){
// Call this function when an event is triggered.
  ThreeSecondTimer.ReStart();
// Timer status indicator.
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, LOW);
}
void loop(){
// Call the update function as fast as possible.
  if(ThreeSecondTimer.Update()){
    digitalWrite(LED_BUILTIN, HIGH);
    ThreeSecondTimer.Stop();
    TwoSecondTimer.ReStart();
  }
// Call the update function as fast as possible.
  if(TwoSecondTimer.Update() && !ThreeSecondTimer.IsActive()){
    digitalWrite(LED_BUILTIN, LOW);
    TwoSecondTimer.Stop();
  }
}

Great thanks Ve7jro. I put your code in my project and it works great, just what I needed. When the arduino is booted up for the first time, it does tigger the the led or in my case the valve. Is there a way to stop that from happening? Thanks — Jason8899, May 08 '21 at 23:24
@Jason8899 _ If you update your question with the complete "sketch", I'll take a look at it for you. Keep in mind that, ThreeSecondTimer.ReStart(); in setup() starts the timer immediately, so you should remove it from setup() and add it to your code, the "event driven" part of your code. — VE7JRO, May 08 '21 at 23:44

Blink LED with different on off times just once with millis

1 Answers1