/*
 * ESP32 Single Relay Test - Minimal Example
 * 
 * This is a simplified version for testing just ONE relay
 * Perfect for beginners or initial hardware testing
 * 
 * Hardware Setup:
 * - Connect ESP32 5V to Relay Module VCC
 * - Connect ESP32 GND to Relay Module GND  
 * - Connect ESP32 GPIO 13 to Relay Module IN1
 * 
 * Commands via Bluetooth:
 * - ON: Turn relay on
 * - OFF: Turn relay off
 * - STATUS: Check relay state
 */

#include "BluetoothSerial.h"

BluetoothSerial SerialBT;

// Relay configuration
const int RELAY_PIN = 13;  // Change this to your GPIO pin
bool relayState = false;

void setup() {
  // Start serial for debugging
  Serial.begin(115200);
  Serial.println("ESP32 Single Relay Test");
  
  // Configure relay pin
  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, HIGH);  // Start with relay OFF (active LOW)
  
  // Start Bluetooth
  SerialBT.begin("ESP32-Test-Relay");
  Serial.println("Bluetooth ready! Device: ESP32-Test-Relay");
  Serial.println("Commands: ON, OFF, STATUS");
}

void loop() {
  // Check for Bluetooth commands
  if (SerialBT.available()) {
    String command = SerialBT.readStringUntil('\n');
    command.trim();
    command.toUpperCase();
    
    Serial.println("Received: " + command);
    
    if (command == "ON") {
      relayState = true;
      digitalWrite(RELAY_PIN, LOW);  // Active LOW relay
      SerialBT.println("Relay is ON");
      Serial.println("Relay is ON");
    }
    else if (command == "OFF") {
      relayState = false;
      digitalWrite(RELAY_PIN, HIGH);  // Active LOW relay
      SerialBT.println("Relay is OFF");
      Serial.println("Relay is OFF");
    }
    else if (command == "STATUS") {
      String status = relayState ? "ON" : "OFF";
      SerialBT.println("Relay: " + status);
      Serial.println("Relay: " + status);
    }
    else {
      SerialBT.println("Unknown command. Use: ON, OFF, or STATUS");
    }
  }
  
  delay(10);
}