Insert argument

Using Arduino Programming Questions
1

How could I insert an argument where it says digitalWrite high to check if the output pin is high; digitalWrite low, if low digitalWrite high.

const int INPUT_PIN = 12;
const int OUTPUT_PIN = 13;

unsigned long startTime = 0;
const unsigned long interval = 5000; // 5 seconds in milliseconds
bool timerStarted = false;
const unsigned long debounceDelay = 50; // 50 milliseconds for debounce
unsigned long lastDebounceTime = 0; // the last time the output pin was toggled

void setup() {
  pinMode(INPUT_PIN, INPUT_PULLUP);
  pinMode(OUTPUT_PIN, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  int state = digitalRead(INPUT_PIN);

  // check if the input has stayed stable for longer than the debounce delay
  if ((millis() - lastDebounceTime) > debounceDelay) {
    // if the current reading has been stable for longer than debounceDelay, take action
    if (state == LOW) {
      if (!timerStarted) {
        // start the timer
        startTime = millis();
        timerStarted = true;
        Serial.println("starting");
      }
      else if (millis() - startTime <= interval) {
        digitalWrite(OUTPUT_PIN, HIGH); // set the output pin high
        Serial.println("success"); // write to serial console
        timerStarted = false; // reset the timer
      }
    }
  }

  // reset the debounce timer
  if (state == LOW) {
    Serial.println("resetting debounce");
    lastDebounceTime = millis();
  }

  // time exceeds 5 seconds without a second trigger, reset the timer
  if (timerStarted && millis() - startTime > interval) {
    Serial.println("5 seconds no trigger; resetting");
    timerStarted = false;
  }
}
2

Sorry, but I cannot make sense of what you want to do. Please try explaining again

3

To start with you don't understand what the word argument means. So maybe try to use some different words that you do know and you will make more sense.

If it says digitalWrite(OUTPUT_PIN, HIGH); then the output pin is HIGH. You don't need to check. You can rest assured.

If you want to also write another pin low at that time, then digitalWrite with that pin number and LOW.

4

@noguru Or, is it that you want to flip the bit, in which case
digitalWrite(OUTPUT_PIN, !digitalRead(OUTPUT_PIN);
would do what you want.
Please, clarify what it is you want, if not that.

5

I'm essentially wanting to toggle the output pin. If a second button press is sensed on the input pin within 5 seconds the output pin is set high and the timer is reset. That works. I need pin 13 to toggle so that the first time the second button press is sensed in the 5 seconds, the output pin goes high and the next cycle it goes low. Alternatively and maybe a better solution, is to have pin 13 go high every time the button is pressed twice and go low every time the button is pressed 3 times within the time period.

6

There is a missing ). Also, this discussion may be relevant:

1 Like
7

Ok, I see what you are wanting. You should set a variable to hold the pin state.

int pinState = LOW;


// in loop

if(the button is pressed) {
   pinState = 1 - pinState;  // toggles LOW and HIGH
   digitalWrite(OUTPUT_PIN, pinState);
}

Now since you're writing the value of the variable pinState to the pin, you can always check pinState to see what was the last value you put there.

if(pinState == HIGH){
   // the pin has been set high
   // if you want to set it low then
   pinState = LOW;
   digitalWrite(OUTPUT_PIN, pinState);
}
8

You could read the pin before you get to the digitalWrite, however if the pin is already high writing digitalWrite(PIN#, HIGH) will do no harm.

9

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