#define ECHO_PIN 14
#define TRIG_PIN 12

#define RED_LED 23
#define YELLOW_LED 19
#define GREEN_LED 18

// Include libraries for servo motor
#include <ESP32Servo.h>

#define SERVO_PIN 2
Servo myservo;

int angle = 0;
bool up = true;

// Include libraries for OLED display
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <Wire.h>

// Define OLED parameters
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
#define SCREEN_ADDRESS 0x3C

// Create OLED display object
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);


void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(YELLOW_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);

  myservo.attach(SERVO_PIN);

  // Initialize display
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  display.display();
  delay(2000);
  display.clearDisplay();
  display.display();
  
}

float readDistanceCM() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}

// Function to print a line of text onto OLED
void print_line(String text, int column, int row) {
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(column, row); // (column, row)
  display.println(text);
  display.display();
}

void loop() {
  float distance = readDistanceCM();
  //float distance =60.0
  String s = String(distance);
  print_line(s, 0, 0);

  if (distance < 60){
    digitalWrite(RED_LED, HIGH);
    digitalWrite(YELLOW_LED, LOW);
    digitalWrite(GREEN_LED, LOW);
    myservo.write(60);
  }else if(distance<240){
    digitalWrite(YELLOW_LED, HIGH);
    digitalWrite(RED_LED, LOW);
    digitalWrite(GREEN_LED, LOW);
    int angle = map(distance, 60, 240, 60, 180);
    myservo.write(angle);
  }else{
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(RED_LED, LOW);
    digitalWrite(YELLOW_LED, LOW);
    myservo.write(180);
  }

  if ((angle==0)||(angle==180)) {
    up = !up;
  }

  delay(500);
  display.clearDisplay();
  display.display();
  delay(500);

}