Interface LCD 16x2 with Arduino

/*
 * LM35 Temperature Sensor with Arduino
 * 
 * Description:
 *   Reads the analog voltage from the LM35 temperature sensor
 *   and converts it to temperature in Celsius and Fahrenheit.
 *   Results are printed to the Serial Monitor.
 * 
 * Wiring:
 *   LM35 VCC  --> Arduino 5V
 *   LM35 OUT  --> Arduino A0
 *   LM35 GND  --> Arduino GND
 */

// Define the analog pin connected to the LM35 output
const int sensorPin = A0;

// Variable to store the raw analog reading (0–1023)
int rawValue = 0;

// Variables to store calculated temperature
float voltage = 0.0;
float temperatureC = 0.0;
float temperatureF = 0.0;

void setup() {
  // Start Serial communication at 9600 baud rate
  // This lets us print messages to the Serial Monitor
  Serial.begin(9600);
  
  // Print a welcome message once when the Arduino starts
  Serial.println("LM35 Temperature Sensor");
  Serial.println("========================");
  Serial.println("Starting readings...");
  Serial.println();
}

void loop() {
  // Step 1: Read the raw analog value from pin A0
  // analogRead() returns a value between 0 and 1023
  rawValue = analogRead(sensorPin);
  
  // Step 2: Convert raw ADC value to voltage
  // Arduino's ADC uses a 5V reference, divided into 1024 steps
  // Formula: voltage = (rawValue / 1023.0) * 5000  (result in millivolts)
  voltage = (rawValue / 1023.0) * 5000;
  
  // Step 3: Convert voltage to Celsius
  // LM35 outputs 10mV per degree Celsius
  // Formula: temperatureC = voltage / 10
  temperatureC = voltage / 10;
  
  // Step 4: Convert Celsius to Fahrenheit (optional)
  // Standard formula: F = (C × 9/5) + 32
  temperatureF = (temperatureC * 9.0 / 5.0) + 32.0;
  
  // Step 5: Print the results to the Serial Monitor
  Serial.print("Raw ADC Value : ");
  Serial.println(rawValue);
  
  Serial.print("Voltage       : ");
  Serial.print(voltage);
  Serial.println(" mV");
  
  Serial.print("Temperature   : ");
  Serial.print(temperatureC);
  Serial.print(" °C  |  ");
  Serial.print(temperatureF);
  Serial.println(" °F");
  
  Serial.println("------------------------");
  
  // Wait 1 second before taking the next reading
  // 1000 milliseconds = 1 second
  delay(1000);
}