Press On Hold Off Power Switch

Question

Hi everyone I am hoping someone here can help me. I am trying to make an arduino turn my project on and off.Using a relay. I am looking for it to act like a computer power button. A short press to turn on and them stay on and a long press (say 5 sec) to turn off and then stay off till button is pressed again. I would like it so that the project can not be accidentally turned off Can anyone please help. Thanks

Answer 1

Here is a test sketch that I wrote for a different question. The other question's requirement was for a short press (minimum 100ms) to turn on an LED, and a long press (1 second) would turn it off. With a slight modification of this sketch, it may work for you. You will need to install the Bounce2 library.

// Press and hold button for 100 ms to turn LED ON.
// Press and hold button for 1000 ms to turn LED OFF.
#include <Bounce2.h>

byte buttonState = 0;
const byte ledPin = 3;
const byte buttonPin = 2;
const unsigned long debouncerInterval = 50;
unsigned long buttonPressedTime = 0;
unsigned long currentMillis = 0;

Bounce debouncer = Bounce();

void setup(){
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  debouncer.attach(buttonPin, INPUT_PULLUP);
  debouncer.interval(debouncerInterval);
}

void loop(){

  // Get the current time.
  currentMillis = millis();

  // Check if button was pressed or released.
  if(debouncer.update()){

    // Pressed.
    if(debouncer.read() == 0){
      if(buttonState == 0){
        buttonState = 1;
        buttonPressedTime = currentMillis;
      }
    }

    // Released.
    else{
      buttonState = 0;
    }
  }

  // Turn the LED ON or OFF.
  if(buttonState == 1){
    if(currentMillis - buttonPressedTime >= 1000){
      digitalWrite(ledPin, LOW);
      buttonState = 0;
    }
    else if(currentMillis - buttonPressedTime >= 100){
      digitalWrite(ledPin, HIGH);
    }
  }
}

Answer 2

To clarify the problem, do you want to control ON OFF using Arduino? It is very simple. Please read this simple tutorial, and modify it according to your needs.