// Simple ESP32 Tilt Detection with MPU-6050
// Detects tilt using accelerometer and triggers alert

#include <Wire.h>

int ledPin = 2;       // LED connected to GPIO 2 (D2)
int buzzerPin = 5;    // Buzzer connected to GPIO 5 (D5)

// MPU-6050 I2C address
const int MPU = 0x68;

// Tilt threshold (adjust sensitivity)
float tiltThreshold = 30.0;  // degrees

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);  // SDA=21, SCL=22 for ESP32
  
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  
  // Initialize MPU-6050
  Wire.beginTransmission(MPU);
  Wire.write(0x6B);  // PWR_MGMT_1 register
  Wire.write(0);     // Wake up MPU-6050
  Wire.endTransmission(true);
  
  Serial.println("MPU-6050 Tilt Detection Ready!");
  Serial.println("Tilt threshold: " + String(tiltThreshold) + " degrees");
  
  // Test components
  digitalWrite(ledPin, HIGH);
  digitalWrite(buzzerPin, HIGH);
  delay(300);
  digitalWrite(ledPin, LOW);
  digitalWrite(buzzerPin, LOW);
}

void loop() {
  // Read accelerometer data
  Wire.beginTransmission(MPU);
  Wire.write(0x3B);  // Starting register for accelerometer
  Wire.endTransmission(false);
  Wire.requestFrom(MPU, 6, true);
  
  // Read X, Y, Z acceleration values
  int16_t AcX = Wire.read() << 8 | Wire.read();
  int16_t AcY = Wire.read() << 8 | Wire.read();
  int16_t AcZ = Wire.read() << 8 | Wire.read();
  
  // Convert to angles (tilt calculation)
  float angleX = atan2(AcY, AcZ) * 180.0 / PI;
  float angleY = atan2(AcX, AcZ) * 180.0 / PI;
  
  // Calculate total tilt angle
  float totalTilt = sqrt(angleX * angleX + angleY * angleY);
  
  // Check if tilted beyond threshold
  if (totalTilt > tiltThreshold) {
    // TILT DETECTED!
    digitalWrite(ledPin, HIGH);      // Turn on LED
    digitalWrite(buzzerPin, HIGH);   // Turn on buzzer
    Serial.print("⚠️ TILT DETECTED! Angle: ");
    Serial.print(totalTilt, 1);
    Serial.println("°");
    
  } else {
    // DEVICE LEVEL
    digitalWrite(ledPin, LOW);       // Turn off LED
    digitalWrite(buzzerPin, LOW);    // Turn off buzzer
    Serial.print("Device level - Tilt: ");
    Serial.print(totalTilt, 1);
    Serial.println("°");
  }
  
  delay(200);
}

/*
WOKWI CIRCUIT CONNECTIONS - MPU-6050 TILT DETECTION:

Components needed:
- ESP32 DevKit V1
- MPU-6050 Accelerometer/Gyroscope
- LED
- 220Ω resistor
- Buzzer (Active buzzer)

Simple connections:

MPU-6050 (I2C connection):
1. MPU-6050 VCC → 3V3
2. MPU-6050 GND → GND
3. MPU-6050 SDA → GPIO 21 (SDA pin)
4. MPU-6050 SCL → GPIO 22 (SCL pin)

LED:
5. LED long leg → GPIO 2 (D2 pin)
6. LED short leg → 220Ω resistor → GND

Buzzer:
7. Buzzer positive (+) → GPIO 5 (D5 pin)
8. Buzzer negative (-) → GND

How it works:
- MPU-6050 measures acceleration in X, Y, Z axes
- Code calculates tilt angle from acceleration data
- Alert triggers when tilt > 30 degrees (adjustable)
- Shows exact tilt angle in serial monitor

Test: In Wokwi, rotate the MPU-6050 to simulate tilting
*/