/************************************************************************************************
  *   LAB TEST 2025 - TRAFFIC LIGHTS                                                            *
  *                                                                                             *
  *   Student Name: Zainab Khan                                                                          *
  *                                                                                             *
  *   Description: You will need to wire and code the following program:                        *
  *   Attach all items (breadboard is optional). When the program runs,                         *
  *   a green, yellow then red light should flash (none at the same time). When                 *
  *   the red light is on, a STOP! message should be displayed on the LCD screen, a SLOW!       * 
  *   message when the yellow light is on and a GO! message when the green light is on.         * 
  *   These messages should flash on and off (a blank screen between messages).                 *
  *   The speed that you cycle through the lights/delays should be controlled by the            *
  *   potentiometer. The delay between lights should range between 200-500 milliseconds.        *
  *   The program must be properly commented, indented and variables must be created            *
  *   using proper naming procedures. You must use PORTB and DDRB commands when setting up and  * 
  *   controlling the LED's. The LiquidCrystal I2C library has been added for you.              *
  *                                                                                             *
  *                               GOOD LUCK!                                                    *
  *                                                                                             *
  ***********************************************************************************************/

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 columns and 2 rows

int potPin = A3; // Potentiometer is connected to A5

int potVal; // variable to store potentiometer reading 

int lightSpeed; // variable for the delay between lights


void setup() {

  lcd.init(); // initialize the lcd
  lcd.backlight(); // turn on backlight

  DDRB = B111111; // setting pins 8 - 13 to outputs

  Serial.begin(9600);

} //end of void setup

void loop() {

  potVal = analogRead(potPin); // read the value from the potentiometer - range (0-1023)
 
  lightSpeed = map(potVal, 0, 1023, 200, 500); // changes the 0-1023 reading to a 200-500 millisecond scale
  
  //displaying lightSpeed
  Serial.print("lightSpeed: ");
  Serial.print(lightSpeed);
  Serial.println("   ");


  lcd.setCursor (5,0); // move the cursor to second column in top row
  lcd.print("GO!"); // print on lcd "GO!"
  lcd.print("    ");

  PORTB = B001000; // turns green LED on 
  delay(lightSpeed);

  lcd.setCursor (5,0); // move the cursor to 5th column in top row
  lcd.print("         ");
  delay(lightSpeed);



  lcd.setCursor (5,0); // move the cursor to 5th column in top row
  lcd.print("SLOW!"); // print on lcd "SLOW!"
  lcd.print("    ");

  PORTB = B010000; // turns yellow LED on
  delay(lightSpeed);

  lcd.setCursor (5,0); // move the cursor to 5ht column in top row
  lcd.print("         ");
  delay(lightSpeed);



  lcd.setCursor (5,0); // move the cursor to 5th column in top row
  lcd.print("STOP!"); // print on lcd "STOP!"
  lcd.print("    ");

  PORTB = B100000; // turns red LED on
  delay(lightSpeed);

  lcd.setCursor (5,0); // move the cursor to 5th column in top row
  lcd.print("         ");
  delay(lightSpeed);

} // end of void loop