Input high, output high for one second - How?

Projects Programming
1

Hey guys!
I just started playing with arduino, and i have to the solve the following problem. If i press a button, an output have to stay high for one second, then go off, no matter how long i press the button, and must not to go high again until i release the button, and press again. Right now it's working with a delay, but it's not really good. Any help would be appreciated.
Thank you!

2

Hi, try the following:

if(digitalRead(button, HIGH){
  digitalWrite(LED, HIGH);
  delay(1000);
  digitalWrite(LED,LOW);
  while(digitalRead(button, HIGH);
}
3

It says too many arguments ito function 'int digitalRead (uint8_t)

int LED = 13;
int buttonPin = 12;
void setup() {
   pinMode(buttonPin, INPUT_PULLUP);
   pinMode(LED, OUTPUT);
 }
void loop(){
   int buttonValue = digitalRead(buttonPin);
   if(digitalRead(buttonPin, LOW )
  digitalWrite(LED, HIGH);
  delay(1000);
  digitalWrite(LED,LOW);
  while(digitalRead(button, LOW);
}
else {
      // Otherwise, turn the LED off
      digitalWrite(LED, LOW);
}
4

Sorry my fault... :sweat_smile:

it has to be:

if(digitalRead(button)){
  digitalWrite(LED, HIGH);
  delay(1000);
  digitalWrite(LED,LOW);
  while(digitalRead(button));
}
5

Don't use delay() as it blocks the Arduino from doing other things.

The best way to do something like this is to check when the button becomes pressed and start a timer. Something like this ...

prevButtonState = buttonState;   // save the previous state
buttonState = digitaRead(buttonPin);
if (buttonState != prevButtonState and buttonState = LOW) { // assumes LOW when pressed
   ledStartTime = millis();
   digitalWrite(ledpin, HIGH);
}

if (millis() - ledStartMIlls() > ledOnInterval) {
   digitalWrite(ledPin, LOW);
}

...R

6

Linze99:
Sorry my fault... :sweat_smile:

it has to be:

if(digitalRead(button)){

digitalWrite(LED, HIGH);
  delay(1000);
  digitalWrite(LED,LOW);
  while(digitalRead(button));
}

Yeah, i tried that but still...

7

Fercsi4646:
If i press a button, an output have to stay high for one second, then go off, no matter how long i press the button, and must not to go high again until i release the button, and press again.

Referencing IDE -> file/examples/digital/stateChangeDetection

Use this to generate a signal which is active for only one pass through the code when it changes.

You can verify you've done it right by using the change to increment a counter and displaying the count value on the serial monitor.

Use the fact of the change (some variable, like buttonWasPressed) to reset a timer.

As long as the timer accumulated value is less than what you've set as a preset/timed out value, make the output high. Else make the output low.