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But always test such things with an oscilloscope. FYI: this is not an ideal debounce function, but it should make the idea clear.

But always test such things with an oscilloscope, no guarantee. FYI: this is not an ideal debounce function, but it should make the idea clear.

EDIT2:

Here is a debounce function that should work:

const uint8_t PIN = 13;

/*
 * Returns debounced value for `PIN`
 */
boolean debounce(void)
{
    // Current state of the pin
    boolean currentState;
    // Last state of the pin, initial value is zero
    static boolean lastCurrentState = 0;
    // Timer
    static unsigned long debounceTimer = millis();
    // Debounced value, initial value is zero
    static boolean debouncedValue = 0;
    
    // We first read the current state of the pin
    currentState = digitalRead(PIN);
    
    // Then we look if the state has changed
    if (currentState != lastCurrentState) {
        // If it has, we need to reset the debounce timer
        debounceTimer = millis();
    }
    
    // Then we check if the timer has expired
    if ((millis() - 50) > debounceTimer) {
        // The timer expired so we update the value
        debouncedValue = currentState;
    }

    // Save the latest state
    lastCurrentState = currentState;
    
    // We always return a debounced value:
    return debouncedValue;
}

But always test such things with an oscilloscope. FYI: this is not an ideal debounce function, but it should make the idea clear.

This probably won't answer your question completely, but here are some notes from me:

buttonState = current ;  //read value again now that bouncing is over

This won't read the value again, it just copies current into buttonValue.

What you wanted is:

buttonState = digitalRead(BUTTON); // read value again now that bouncing is over

You have multiple issues with your debounce call:

• lastTimeDebounce is never used by your code, so it is always zero.
• lastButtonState will be always buttonVal making the debounce function useless.

Some other tips:

• Don't use the same names for parameters as for global variables:

  boolean debounce(boolean lastButton, long lastDebounce, int BUTTON)

  The global variable BUTTON will be shadowed by int BUTTON, essentially overriding it.

• Don't use global variables (unless you have a very good reason)

This probably won't answer your question completely, but here are some notes from me:

buttonState = current ;  //read value again now that bouncing is over

This won't read the value again, it just copies current into buttonValue.

What you wanted is:

buttonState = digitalRead(BUTTON); // read value again now that bouncing is over

You have multiple issues with your debounce call:

• lastTimeDebounce is never used by your code, so it is always zero.
• lastButtonState will be always buttonVal making the debounce function useless.

Some other tips:

• Don't use the same names for parameters as for global variables:

  boolean debounce(boolean lastButton, long lastDebounce, int BUTTON)

  The global variable BUTTON will be shadowed by int BUTTON, essentially overriding it.

• Don't use global variables (unless you have a very good reason)

EDIT

I would strongly recommend writing a function that debounces only one pin.

Because if you want a function which can debounce any pin you would need a state variable for each pin (which needs arrays hence a lot of space).