Pin state fluctuation

[WBr]

I use a wemos mini d1 for a project with my pi and Node-Red

When I provide 3V to a pin (D4/GPIO 2) it should give me "high" state. when not connected it should be "Low"

But when I switch the toggle Node-Red start to act strange...

This is one toggle movement:

cleared the debug and toggled the switch back and got this:

could someone help me with how I can get 1 high when the pin state is high? and only 1 low when the pin state is low?

[Colin]

If, each time you change the connection, you get a short sequence of high and low and after a few milliseconds the value stabilises on the correct signal, then that is caused by Switch bounce as it opens or closes. You need to implement debounce logic in the s/w on the D1.

[gerry]

Or if you determine it is contact bounce and s/w doesn't fix it you can put in a hardware debounce circuit

[WBr]

Brilliant! It works like a charm

const int triggerPin = D4;  // Pin to monitor
bool isTriggered = false;   // Flag to track trigger status
bool triggerState = LOW;    // Current state of the trigger pin
bool lastTriggerState = LOW; // Previous state of the trigger pin
long debounceDelay = 50;    // Debounce delay time in milliseconds
long lastDebounceTime = 0;  // Time of the last pin state change

void setup() {
  Serial.begin(115200);
  pinMode(triggerPin, INPUT_PULLUP);

// Read the state of the trigger pin
  int reading = digitalRead(triggerPin);

  // Check if the current state of the trigger pin is different from the previous state
  if (reading != lastTriggerState) {
    // Reset the debounce timer
    lastDebounceTime = millis();
  }

  // Check if the debounce delay has passed
  if ((millis() - lastDebounceTime) > debounceDelay) {
    // Check if the current state of the trigger pin is different from the stored state
    if (reading != triggerState) {
      triggerState = reading;

      // Check for trigger transition from low to high
      if (triggerState == HIGH) {
        Serial.println(20);
        isTriggered = true;

        // Add your message or data to send here
      } else {
        // Check for trigger transition from high to low
        Serial.println(50);
        isTriggered = false;