Garage: new pin for moisture sensor

Doorbell: Vibration motor connected via PC817C optocoupler

doorbell/klingel_sender_nano_serial/klingel_sender_nano_serial.ino

@@ -1,35 +1,31 @@
 /*  Klingel-Sensor auf Arduino Nano ATmega168
  * 
  *  https://www.arduino.cc/en/Tutorial/BuiltInExamples/Button
- *  https://elektro.turanis.de/html/prj035/index.html
- * 
- *  D2  -------------
- *          |       |
- *        10kOhm    |
- *          |       |
- *  +5V -----       |
- *                Button
- *                  |
- *  GND -------------
+ *  https://docs.arduino.cc/tutorials/generic/digital-input-pullup/
  */
 
+
 const int ledPin = LED_BUILTIN;
 const int buttonPin = 2; // Button connected to D2
 const int flare_threshold = 200;
 const int ring_delay = 250;
 
+
 bool active = false;
 
+
 void setup() {
   pinMode(ledPin, OUTPUT);
-  pinMode(buttonPin, INPUT);
+  pinMode(buttonPin, INPUT_PULLUP);
   Serial.begin(9600);
   Serial.println("Doorbell sensor");
 }
 
+
 void loop() {
   int val = digitalRead(buttonPin);
 
+
   if (val == LOW) {
     delay(flare_threshold); // catch flares
     val = digitalRead(buttonPin);
@@ -45,8 +41,10 @@ void loop() {
       Serial.print(flare_threshold);
       Serial.println(")");
     }
-  } else {
+  }
+  else {
     digitalWrite(ledPin, LOW);
     active = false;
   }
 }
+