#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define PRESSURE_PIN A0
#define LED_PIN 7

float voltage;
float pressure;

const float LOW_PRESSURE = 28.0;
const float HIGH_PRESSURE = 36.0;

void setup() {
  Serial.begin(9600);
  pinMode(LED_PIN, OUTPUT);

  // Initialize OLED
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED not found");
    while (1);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
}

void loop() {

  int adc = analogRead(PRESSURE_PIN);

  // Convert to voltage
  voltage = adc * (5.0 / 1023.0);

  // Convert to pressure
  pressure = ((voltage - 0.5) / 4.0) * 100.0;

  if (pressure < 0) pressure = 0;

  Serial.print("Voltage = ");
  Serial.print(voltage);
  Serial.print(" V   Pressure = ");
  Serial.print(pressure);
  Serial.println(" PSI");

  // OLED DISPLAY
  display.clearDisplay();

  display.setCursor(0, 0);
  display.println("Tire Monitor");

  display.setCursor(0, 15);
  display.print("Volt: ");
  display.print(voltage, 2);
  display.println(" V");

  display.setCursor(0, 30);
  display.print("ضغط: ");
  display.print(pressure, 1);
  display.println(" PSI");

  // Warning logic
  if (pressure < LOW_PRESSURE || pressure > HIGH_PRESSURE) {
    digitalWrite(LED_PIN, HIGH);

    display.setCursor(0, 50);
    display.println("WARNING!");

    Serial.println("⚠ WARNING: Tire Pressure Abnormal!");
  } else {
    digitalWrite(LED_PIN, LOW);

    display.setCursor(0, 50);
    display.println("Normal");
  }

  display.display();

  delay(500);
}