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

const float ADC_VREF_mV = 3300.0;// in millivolt
const float ADC_RESOLUTION = 4096.0;
const int PIN_LM35 = 4; // ESP32 pin GPIO4 (ADC2_0) connected to LM35

const int ledPins[] = {32, 33, 25, 26, 27, 14};  // Pin LED

#define SCREEN_WIDTH 128 // OLED width,  in pixels
#define SCREEN_HEIGHT 64 // OLED height, in pixels

Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  for (int i = 0; i < 6; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("failed to start SSD1306 OLED"));
    while (1);
  }
}

void loop() {
  int adcVal = analogRead(PIN_LM35);
  float adcValVoltage = adcVal * (ADC_VREF_mV / ADC_RESOLUTION);
  float tempC = adcValVoltage / 10;
  float x = (53+31+3+3)*0.01;
  float temperature = tempC * x;

  Serial.print("Temperature: ");
  Serial.print(temperature);   // print the temperature in °C
  Serial.println("°C");

  if (temperature < 27) {
    digitalWrite(ledPins[0], HIGH);
    digitalWrite(ledPins[1], HIGH);
    digitalWrite(ledPins[2], LOW);
    digitalWrite(ledPins[3], LOW);
    digitalWrite(ledPins[4], LOW);
    digitalWrite(ledPins[5], LOW);
  } else if (temperature >= 27 && temperature <= 29) {
    digitalWrite(ledPins[0], HIGH);
    digitalWrite(ledPins[1], HIGH);
    digitalWrite(ledPins[2], HIGH);
    digitalWrite(ledPins[3], LOW);
    digitalWrite(ledPins[4], LOW);
    digitalWrite(ledPins[5], LOW);
  } else if (temperature > 29 && temperature <= 31) {
    digitalWrite(ledPins[0], HIGH);
    digitalWrite(ledPins[1], HIGH);
    digitalWrite(ledPins[2], HIGH);
    digitalWrite(ledPins[3], HIGH);
    digitalWrite(ledPins[4], LOW);
    digitalWrite(ledPins[5], LOW);
  } else {
    digitalWrite(ledPins[0], HIGH);
    digitalWrite(ledPins[1], HIGH);
    digitalWrite(ledPins[2], HIGH);
    digitalWrite(ledPins[3], HIGH);
    digitalWrite(ledPins[4], HIGH);
    digitalWrite(ledPins[5], HIGH);
    blinkLEDs();
  }

  oled.clearDisplay(); // clear display

  oled.setTextSize(2);         // set text size
  oled.setTextColor(WHITE);    // set text color
  oled.setCursor(14, 28);       // set position to display (x,y)
  oled.print(temperature);
  oled.print((char)247);
  oled.print("C");

  oled.display();              // display on OLED

}

void blinkLEDs() {
  static bool state = false;
  digitalWrite(ledPins[4], state);
  digitalWrite(ledPins[5], state);
  state = !state;
  delay(2000);
}