Serial Monitor statements

Projects Programming
8

Hello,
if someone is interested reading:
i tried that prevState proposal by tuxdino and tadaaah! Seems to work. Thank you :slight_smile:

  int prevState = 0;
  int nowState = 0;
  // i'm two int variables
  
void setup() {
  Serial.begin(9600);

}

void loop() {

  int sensorValue = analogRead(A0);
  prevState = sensorValue;
  // prevState gets the actual number
  delay (1);
  sensorValue = analogRead(A0);
  // read once again
  nowState = sensorValue;
  // nowState is even more actal!!!
  if (nowState>500 && prevState<500)
    {
       Serial.println("UP");
            }
  if (nowState<500 && prevState>500)
      {
         Serial.println("DOWN");
            }
}

Only thing i don't understand:
Every now and then the monitor doesn't change like tic tac between the two statements, but prints the same statement 'UP' or 'DOWN' twice - how can this happen? Once the analog signal goes from up to down it has to go up again to go down, right? This is a mystery to me... Might have something to do with debouncing?
Anyway, thanks everybody for reading and commenting. It helped me a lot.
(The next thing i want to do is count the time between the changes and print it insdead of printing UP or DOWN.)