/*
==== Task 4 - LED Chase Sequence Using a Function ====
              Author: Roberto Palozzo
======================================================
*/
 
#include <Wire.h>                   // I2C communication library
#include <Adafruit_GFX.h>           // graphics library for the OLED
#include <Adafruit_SSD1306.h>       // driver library for the OLED display
 
#define SCREEN_WIDTH 128            // OLED width in pixels
#define SCREEN_HEIGHT 64            // OLED height in pixels
#define OLED_SDA 35                 // I2C data pin
#define OLED_SCL 0                  // I2C clock pin
 
int buzzerPin = 10;  // pin connected to the buzzer
 
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);  // create OLED display object
 
// Turns on a single LED for "delayTime" ms, then turns it off
void lightLED(int ledPin, int delayTime) {
  digitalWrite(ledPin, HIGH);       // turn LED on
  delay(delayTime);                 // keep it on
  digitalWrite(ledPin, LOW);        // turn LED off
}
 
// Runs once, every time the chase completes a full lap
void endOfSequence() {
  tone(buzzerPin, 1000);            // play a short beep
  delay(200);
  noTone(buzzerPin);                // stop the beep
  
  display.clearDisplay();           // clear old content
  display.setTextSize(2);           // set text size
  display.setCursor(0, 20);         // set text position
  display.println("Lap done!");     // write message
  display.display();                // show it on screen
  delay(500);                       // keep message visible
  display.clearDisplay();           // clear message
  display.display();                // update screen (now blank)
}
 
void setup() {
  pinMode(4, OUTPUT);               // set pin 4 as output
  pinMode(5, OUTPUT);               // set pin 5 as output
  pinMode(6, OUTPUT);               // set pin 6 as output
  pinMode(7, OUTPUT);               // set pin 7 as output
  pinMode(buzzerPin, OUTPUT);       // set buzzer pin as output
 
  Wire.begin(OLED_SDA, OLED_SCL);                // start I2C on custom pins
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);     // initialize OLED at I2C address 0x3C
  display.clearDisplay();                        // clear display buffer
  display.setTextColor(SSD1306_WHITE);           // set text color
  display.display();                             // apply initial blank screen
}
 
void loop() {
  lightLED(4, 200);   // chase LED 1
  lightLED(5, 200);   // chase LED 2
  lightLED(6, 200);   // chase LED 3
  lightLED(7, 200);   // chase LED 4
 
  endOfSequence();    // buzzer beep + OLED message at the end of each full chase
}