// Lift Control Code for Arduino Uno

// Define the pin numbers for the limit switches, the relays, and the push buttons
const int topLimitSwitch = 2;   // Top limit switch connected to pin 2
const int bottomLimitSwitch = 3;   // Bottom limit switch connected to pin 3
const int relay1 = 4;   // Relay 1 connected to pin 4
const int relay2 = 5;   // Relay 2 connected to pin 5
const int insideButton = 8; // Inside button connected to pin 8

// Define the pin numbers for the push buttons
const int groundFloorButton = 6;   // Ground floor button connected to pin 6
const int firstFloorButton = 7;   // First floor button connected to pin 7

// Define the variables to store the current floor and the destination floor
int currentFloor = 0;   // Start at ground floor
int destinationFloor = 0;

void setup() {
  // Set the pin modes for the limit switches, the relays, and the push buttons
  pinMode(topLimitSwitch, INPUT_PULLUP);
  pinMode(bottomLimitSwitch, INPUT_PULLUP);
  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);
  pinMode(groundFloorButton, INPUT_PULLUP);
  pinMode(firstFloorButton, INPUT_PULLUP);
  pinMode(insideButton, INPUT_PULLUP);
}

void loop() {
  // Check if the lift is at the top or bottom floor
  if (digitalRead(topLimitSwitch) == LOW) {
    currentFloor = 1;
  } else if (digitalRead(bottomLimitSwitch) == LOW) {
    currentFloor = 0;
  }
  
  // Check if a button has been pressed on either floor or inside the lift
  if (digitalRead(groundFloorButton) == LOW) {
    destinationFloor = 0;
  } else if (digitalRead(firstFloorButton) == LOW) {
    destinationFloor = 1;
  } else if (digitalRead(insideButton) == LOW) {
    destinationFloor = (currentFloor + 1) % 2; // Change the destination floor to the other floor
  }
  
  // Move the lift to the destination floor
  if (destinationFloor > currentFloor) {
    digitalWrite(relay1, HIGH);   // Activate relay 1 to move the lift up
    digitalWrite(relay2, LOW);    // Deactivate relay 2
  } else if (destinationFloor < currentFloor) {
    digitalWrite(relay1, LOW);    // Deactivate relay 1
    digitalWrite(relay2, HIGH);   // Activate relay 2 to move the lift down
  } else {
    digitalWrite(relay1, LOW);    // Deactivate both relays
    digitalWrite(relay2, LOW);
  }
}