Answer ball on an Arduino Uno

// Answer ball: ask a yes-or-no question, tip the tilt switch, and the LCD
// shows an answer picked at random.
//
//   LCD     RS -> pin 12, E -> pin 11, D4 to D7 -> pins 5, 4, 3, 2
//           VSS, RW, K -> GND; VDD, A -> 5V; V0 -> GND for full contrast
//   pin 6   the tilt switch, its other leg to GND (internal pull-up)
//
// random(8) picks a number from 0 to 7, and that number picks a line from
// the table. The numbers come from a generator that would start the same way
// every time, so setup() seeds it from analogRead of a pin with nothing on it,
// which wanders a little.

#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

const int TILT = 6;

const char *ANSWERS[8] = {
    "Yes", "Most likely", "Certainly", "Outlook good",
    "Unsure", "Ask again", "Doubtful", "No",
};

int lastTilt = LOW;

void setup() {
  pinMode(TILT, INPUT_PULLUP);
  lcd.begin(16, 2);
  lcd.print("Ask me a");
  lcd.setCursor(0, 1);
  lcd.print("question");
  randomSeed(analogRead(A5));
  Serial.begin(9600);
  Serial.println("Mokxi Uno: answer ball. Tip it to ask.");
  lastTilt = digitalRead(TILT);
}

void loop() {
  int tilt = digitalRead(TILT);
  // Tipped over: the switch opens and the pull-up reads HIGH.
  if (tilt != lastTilt && tilt == HIGH) {
    const char *answer = ANSWERS[random(8)];
    lcd.clear();
    lcd.print("The ball says:");
    lcd.setCursor(0, 1);
    lcd.print(answer);
    Serial.print("answer: ");
    Serial.println(answer);
  }
  lastTilt = tilt;
  delay(20);
}