GY-89 10DOF LSM303D+L3GD20 +BMP180 sensor module

// Pin definitions for GY-89 chip select
#define CS1_PIN 8   // Connect to CS1 on GY-89
#define CS2_PIN 9   // Connect to CS2 on GY-89

void selectBMP180() {
  digitalWrite(CS1_PIN, HIGH);
  digitalWrite(CS2_PIN, HIGH);
}

void selectL3GD20() {
  digitalWrite(CS1_PIN, HIGH);
  digitalWrite(CS2_PIN, LOW);
}

void selectLSM303D() {
  digitalWrite(CS1_PIN, LOW);
  digitalWrite(CS2_PIN, HIGH);
}

/*
  GY-89 10DOF Module – Complete Sensor Initialization Example
*/

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP085.h>
#include <Adafruit_LSM303_Accel.h>
#include <Adafruit_LSM303_Mag.h>
#include <L3G.h>

// Pin definitions for chip select
#define CS1_PIN 8
#define CS2_PIN 9

// Create sensor objects
Adafruit_BMP085 bmp;
Adafruit_LSM303_Accel_Unified accel = Adafruit_LSM303_Accel_Unified(12345);
Adafruit_LSM303_Mag_Unified mag = Adafruit_LSM303_Mag_Unified(12345);
L3G gyro;

void setup() {
  Serial.begin(115200);
  Wire.begin();
  
  // Configure chip select pins as outputs
  pinMode(CS1_PIN, OUTPUT);
  pinMode(CS2_PIN, OUTPUT);
  
  // Initialize BMP180 Barometer
  selectBMP180();
  if (!bmp.begin()) {
    Serial.println("BMP180 not found!");
  } else {
    Serial.println("BMP180 OK");
  }
  
  // Initialize L3GD20 Gyroscope
  selectL3GD20();
  if (!gyro.init()) {
    Serial.println("L3GD20 not found!");
  } else {
    gyro.enableDefault();
    Serial.println("L3GD20 OK");
  }
  
  // Initialize LSM303D Accelerometer
  selectLSM303D();
  if (!accel.begin()) {
    Serial.println("LSM303D Accelerometer not found!");
  } else {
    Serial.println("LSM303D Accelerometer OK");
  }
  
  // Initialize LSM303D Magnetometer
  if (!mag.begin()) {
    Serial.println("LSM303D Magnetometer not found!");
  } else {
    Serial.println("LSM303D Magnetometer OK");
  }
  
  Serial.println("GY-89 All Sensors Ready");
}

void selectBMP180() {
  digitalWrite(CS1_PIN, HIGH);
  digitalWrite(CS2_PIN, HIGH);
}

void selectL3GD20() {
  digitalWrite(CS1_PIN, HIGH);
  digitalWrite(CS2_PIN, LOW);
}

void selectLSM303D() {
  digitalWrite(CS1_PIN, LOW);
  digitalWrite(CS2_PIN, HIGH);
}

void loop() {
  // Read BMP180 (Barometer)
  selectBMP180();
  float temperature = bmp.readTemperature();
  float pressure = bmp.readPressure() / 100.0;  // Convert to hPa
  float altitude = bmp.readAltitude();
  
  // Read L3GD20 (Gyroscope)
  selectL3GD20();
  gyro.read();
  float gx = gyro.g.x, gy = gyro.g.y, gz = gyro.g.z;
  
  // Read LSM303D (Accelerometer)
  selectLSM303D();
  sensors_event_t accelEvent;
  accel.getEvent(&accelEvent);
  
  // Read LSM303D (Magnetometer)
  sensors_event_t magEvent;
  mag.getEvent(&magEvent);
  
  // Calculate heading (degrees from North)
  float heading = atan2(magEvent.magnetic.y, magEvent.magnetic.x);
  if(heading < 0) heading += 2 * PI;
  heading = heading * 180 / PI;
  
  // Display results
  Serial.print("Temp: "); Serial.print(temperature); Serial.println(" °C");
  Serial.print("Pressure: "); Serial.print(pressure); Serial.println(" hPa");
  Serial.print("Altitude: "); Serial.print(altitude); Serial.println(" m");
  Serial.print("Gyro (°/s): "); Serial.print(gx); Serial.print(", "); Serial.print(gy); Serial.print(", "); Serial.println(gz);
  Serial.print("Heading: "); Serial.println(heading);
  
  delay(500);
}

float calculateTiltCompensatedHeading(float accX, float accY, float accZ, float magX, float magY, float magZ) {
  // Calculate pitch and roll from accelerometer
  float pitch = atan2(-accX, sqrt(accY * accY + accZ * accZ));
  float roll = atan2(accY, accZ);
  
  // Tilt compensate magnetometer readings
  float magX_comp = magX * cos(pitch) + magZ * sin(pitch);
  float magY_comp = magX * sin(roll) * sin(pitch) + magY * cos(roll) - magZ * sin(roll) * cos(pitch);
  
  // Calculate heading
  float heading = atan2(magY_comp, magX_comp);
  if(heading < 0) heading += 2 * PI;
  return heading * 180 / PI;
}