/* * Lab 1 - Task 5: Basic ADC with Potentiometer & I2C LCD
 * Objective: Read analog values and display them on Serial and LCD.
 */

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Set the LCD address to 0x27 for a 16 chars and 2 line display
// If 0x27 doesn't work, try 0x3F
LiquidCrystal_I2C lcd(0x27, 16, 2); 

// Define your new custom I2C pins 
const int custom_SDA = 4; 
const int custom_SCL = 5;

const int potPin = 18;      // Potentiometer connected to GPIO 34 (ADC1_CH6)

void setup() {
  Serial.begin(115200);     // Initialize Hyperterminal / Serial Monitor

	 //Start the I2C bus with the custom pins 
 Wire.begin(custom_SDA, custom_SCL);
  
  // Initialize the LCD
  lcd.init();
  lcd.backlight();          // Turn on the LCD backlight
  
  // Print a welcome message
  lcd.setCursor(0, 0);      // Column 0, Row 0
  lcd.print("ESP32 ADC Lab");
  lcd.setCursor(0, 1);      // Column 0, Row 1
  lcd.print("Initializing...");
  
  Serial.println("Task 5 Ready: Reading Potentiometer...");
  delay(2000);              // Wait for 2 seconds before clearing
  lcd.clear();
}

void loop() {
  // 1. Read the raw ADC value (0 to 4095)
  int adcValue = analogRead(potPin);

  // 2. Convert the raw value to Voltage (0.0V to 3.3V)
  // Formula: (ADC_Value * Max_Voltage) / Max_ADC_Resolution
  float voltage = adcValue * (3.3 / 4095.0);

  // 3. Display on Hyperterminal (Serial Monitor)
  Serial.print("Raw ADC Value: ");
  Serial.print(adcValue);
  Serial.print("\t Voltage: ");
  Serial.print(voltage);
  Serial.println(" V");

  // 4. Display on I2C LCD 16x2
  // Format Row 0 -> "ADC: 4095    "
  lcd.setCursor(0, 0);
  lcd.print("ADC: ");
  lcd.print(adcValue);
  lcd.print("    ");        // Extra spaces to clear trailing characters

  // Format Row 1 -> "Volt: 3.30 V   "
  lcd.setCursor(0, 1);
  lcd.print("Volt: ");
  lcd.print(voltage);
  lcd.print(" V  ");

  delay(500);               // Update every half second
}