int pbVal = 0;
int pbPin;
#define ledPin 13

void setup() {
  Serial.begin(9600);
  Serial.println("Test Push Button");
  Serial.println("================");
  Serial.println();
  Serial.println("Connecting guidelines:");
  Serial.println("Place the PB above the mid rail of the breadboard");
  Serial.println("in way that two legs are on one side of the rail");
  Serial.println("and the other two legs are on the other side");
  Serial.println();
  Serial.println("One leg is connected to 5V");
  Serial.println("the opposite leg is connected to digital pin, and");
  Serial.println("to a 10K Ohm resistor that goes to GND");
  Serial.println("This is PULL DOWN connection");
  Serial.println();
  Serial.println();
  Serial.println("The program reads the state of the button (pressed or released)");
  Serial.println("and prints the state to screen and controlls the on board led");

  pinMode(ledPin, OUTPUT);

  Serial.println();
  Serial.println();
  Serial.println("Enter the pin number that the PB is connected to:");
  while (Serial.available() == 0);
  pbPin = Serial.parseInt();
  while (pbPin < 2 || pbPin > 13) {
    Serial.println("Pin number " + String(pbPin) + " is invalid.");
    Serial.println("Check your connection and/or eneterd data");
    Serial.println();
    Serial.println("Enter the pin number that the PB is connected to:");
    Serial.println();
    while (Serial.available() == 0);
    pbPin = Serial.parseInt();
  }
  pinMode(pbPin, INPUT);
}

void loop() {

  pbVal = digitalRead(pbPin);
  Serial.println("PB state is:" + String((pbVal ? "HIGH" : "LOW")) );
  digitalWrite(ledPin, pbVal);
  delay(1000);
}