Turn off light with Blynk after PIR detects motion

[John93]

Hey there,

first of all you must keep your void loop clean, the ideal blynk void loop should look like this

void loop() {
  Blynk.run();
}

Check this out

Keep your void loop() clean

second,

@rickler

int value = digitalRead(PIR);
  //if its high or if an any object is detected it will activate the LED
  if (value == HIGH) {
    digitalWrite(LED, HIGH);
    digitalWrite(relay1, LOW);
  }
  else {
    digitalWrite(LED, LOW);
    digitalWrite(relay1, HIGH);
  }

Use this in a separate void function and call it using a blynk timer.
For more details, read this topic

Using BlynkTimer or SimpleTimer

Many users seem to struggle with the basic concepts of using BlynkTimer in their projects, despite the excellent discussions and tutorials that exist on this forum, so I thought I’d write a guide that will hopefully help clarify things. It’s rather long, as it attempts to explain the reasoning behind why and how we use timers, and covers some more advanced subjects, but I’ve tried to organise it in a way that helps people to find answers to specific questions… Why use a timer at all? Let’s say …