Problem with butttons and i2c lcd

Projects Programming
7

In the code below you are checking for the state of the button rather than the change in state of the button (i.e., not pressed -> pressed). This in combination with the 5s delay in your code means that you have to hold the a button and release it at exactly the right time to cause an action to happen. Study the following tutorials:

StateChangeDetection
Example-code for timing based on millis()
BlinkWithoutDelay

  buttonState1 = digitalRead(buttonPin1);
  buttonState2 = digitalRead(buttonPin2);
  buttonState2 = digitalRead(buttonPin3);
  if (buttonState1 == HIGH) {
    letter = letter + 1;
    buttonState1 == LOW;
  }

  if (buttonState2 == HIGH) {
    letter = letter - 1;
    buttonState2 == LOW;
  }
  // lcd.setCursor(0, 0);

  // lcd.setCursor(0,1);
  // lcd.print(val);

  if (buttonState3 == HIGH) {
    print = true;
    lcd.setCursor(0, 0);
    lcd.print("A letter has been entered!");
  }

The following code:

  switch (letter) {
    case 1:
      lcd.print('a');
      val = 'a';
      break;

    case 2:
      lcd.print('b');
      val = 'b';
      break;
      .
      .
      .
    case 26:
      lcd.print('z');
      val = 'z';
      break;
  }

can be replaced by:

  val = 'a' + letter;
  lcd.print(val);