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

// DEFINE SENSOR PIN
const int lm35Pin = 32;
const int ldrPin = 34;
const int voltageSensorPin = 35;
const int soilMoisturePin = 39; // Example analog pin for soil moisture sensor

// Define relay
const int relayPin = 27; // Example digital pin for relay

// Voltage divider resistors
const float R1 = 30000.0;
const float R2 = 7500.0;

// Soil moisture threshold
const int soilMoistureThreshold = 2000;

// Initialize LCD
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  // Initialize the serial communication
  Serial.begin(115200);
  Serial.println("SOLAR POWER MONITORING SYSTEM");
  Serial.println("======================================");
  Serial.println();

  // Initialize the LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Starting up...");

  // Delay to allow the LCD to initialize properly
  delay(2000); // 2 seconds delay

  // Configure the analog pins as input (optional as it's the default)
  pinMode(lm35Pin, INPUT);
  pinMode(ldrPin, INPUT);
  pinMode(voltageSensorPin, INPUT);
  pinMode(soilMoisturePin, INPUT);

  // Configure the relay pin as output and ensure it is off initially
  pinMode(relayPin, OUTPUT);
  digitalWrite(relayPin, LOW); // Ensure the relay is initially off (active low)
}

void loop() {
  // Read and process LM35 data, LDR and VOLTAGE SENSOR
  float temperatureC = readTemperature();
  float lux = readLDR();
  float vIN = readVoltage();

  // Read and process Soil Moisture Sensor data
  int soilMoistureValue = analogRead(soilMoisturePin);
  Serial.print("Soil Moisture Value: ");
  Serial.println(soilMoistureValue);

  // Control the relay based on the soil moisture value
  if (soilMoistureValue < soilMoistureThreshold) {
    Serial.println("Soil is dry, turning on the pump...");
    digitalWrite(relayPin, HIGH); // Turn on the relay (active low)
  } else {
    Serial.println("Soil is wet, turning off the pump...");
    digitalWrite(relayPin, LOW); // Turn off the relay
  }

  // Print a separator for readability
  Serial.println("---------------------------------------------");
  Serial.println();

  // Print the values to the LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Tmp:");
  lcd.print(temperatureC, 1);  // Print temperature with 1 decimal place

  lcd.setCursor(9, 0);
  lcd.print("V:");
  lcd.print(vIN, 1);  // Print voltage with 1 decimal place

  lcd.setCursor(0, 1);
  lcd.print("Lux:");
  lcd.print(lux, 0);  // Print light level without decimal places

  lcd.setCursor(9, 1);
  lcd.print("M:");
  lcd.print(soilMoistureValue);  // Print soil moisture value

  // Delay before the next reading
  delay(2000);
}

float readTemperature() {
  // Read the analog value from the LM35
  int lm35Value = analogRead(lm35Pin);

  // Convert the analog value to voltage (for ESP32 with 12-bit ADC)
  float voltage = lm35Value * (3.3 / 4095.0);

  // Convert the voltage to temperature in Celsius
  float temperatureC = voltage * 100.0;

  // Print the temperature in Celsius
  Serial.println("Temperature Sensor (LM35):");
  Serial.print("  Temperature: ");
  Serial.print(temperatureC);
  Serial.println(" °C");
  Serial.println();

  return temperatureC;
}

float readLDR() {
  // Read the analog value from the LDR
  int ldrValue = analogRead(ldrPin);

  // Convert the analog value to voltage (for ESP32 with 12-bit ADC)
  float voltage = ldrValue * (3.3 / 4095.0);

  // Calculate the resistance of the LDR (assuming a 10kΩ resistor in series with the LDR)
  float RLDR = (10000.0 * (3.3 - voltage)) / voltage;

  // Convert the resistance to a light level (Lux)
  float Lux = RLDR / 500;

  // Print the LDR value and the corresponding light level in Lux
  Serial.println("Light Sensor (LDR):");
  Serial.print("  LDR Value: ");
  Serial.print(ldrValue);
  Serial.print("  /  Voltage: ");
  Serial.print(voltage, 4); // Print voltage with 4 decimal places
  Serial.print(" V  /  Light Level: ");
  Serial.print(Lux);
  Serial.println(" Lux");
  Serial.println();

  return Lux;
}

float readVoltage() {
  // Read the analog value from the voltage sensor
  int sensorValue = analogRead(voltageSensorPin);

  // Convert the analog value to voltage (for ESP32 with 12-bit ADC)
  float vOUT = sensorValue * (3.3 / 4095.0);

  // Calculate the input voltage using the voltage divider formula
  float vIN = vOUT / (R2 / (R1 + R2));

  // Print the voltage sensor value and the corresponding input voltage
  Serial.println("Voltage Sensor:");
  Serial.print("  Sensor Value: ");
  Serial.print(sensorValue);
  Serial.print("  /  Output Voltage: ");
  Serial.print(vOUT, 4); // Print output voltage with 4 decimal places
  Serial.print(" V  /  Input Voltage: ");
  Serial.print(vIN);
  Serial.println(" V");
  Serial.println();

  return vIN;
}