#include <Wire.h>
#include <BMP180.h>
#include <SPI.h>
#include <SD.h>

const int chipSelect = 4;
// Store an instance of the BMP180 sensor.
BMP180 barometer;
// We are going to use the on board LED for an indicator.
int indicatorLed = 13;

// Store the current sea level pressure at your location in Pascals.
float seaLevelPressure = 101325;

void setup()
{
  // We start the serial library to output our messages.
  Serial.begin(9600);
  // We start the I2C on the Arduino for communication with the BMP180 sensor.
  Wire.begin();
  // Set up the Indicator LED.
  pinMode(indicatorLed, OUTPUT);
  // We create an instance of our BMP180 sensor.
  barometer = BMP180();
  // We check to see if we can connect to the sensor.
  if (barometer.EnsureConnected())
  {
    Serial.println("Connected to BMP180."); // Output we are connected to the computer.
    digitalWrite(indicatorLed, HIGH); // Set our LED.

    // When we have connected, we reset the device to ensure a clean start.
    barometer.SoftReset();
    // Now we initialize the sensor and pull the calibration data.
    barometer.Initialize();
  }
  else
  {
    Serial.println("No sensor found.");
    digitalWrite(indicatorLed, LOW); // Set our LED.
  }

  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }


  Serial.print("Initializing SD card...");

  // see if the card is present and can be initialized:
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
    // don't do anything more:
    return;
  }
  Serial.println("card initialized.");
}

void loop()
{
  if (barometer.IsConnected)
  {
    // Retrive the current pressure in Pascals.
    long currentPressure = barometer.GetPressure();

    // Print out the Pressure.
   Serial.print("Pressure: ");
    Serial.print(currentPressure);
     Serial.print(" Pa");

    // Retrive the current altitude (in meters). Current Sea Level Pressure is required for this.
    float altitude = barometer.GetAltitude(seaLevelPressure);

    // Print out the Altitude.
    Serial.print("\tAltitude: ");
    Serial.print(altitude);
    Serial.print(" m");

    // Retrive the current temperature in degrees celcius.
    float currentTemperature = barometer.GetTemperature();

    // Print out the Temperature
    Serial.print("\tTemperature: ");
    Serial.print(currentTemperature);
    Serial.print(" C");
    Serial.println(); // Start a new line.
    delay(1000); // Show new results every second.
  }




// open the file. note that only one file can be open at a time,
  // so you have to close this one before opening another.
  File dataFile = SD.open("datalog.txt", FILE_WRITE);

  // if the file is available, write to it:
  if (dataFile) {

  dataFile.print("\tAltitude: ");
   dataFile.print(altitude);
    dataFile.print(" m");
    dataFile.print("Pressure: ");
    dataFile.print(currentPressure);
     dataFile.print(" Pa");
    dataFile.print("\tTemperature: ");
    dataFile.print(currentTemperature);
    dataFile.print(" C");

   dataFile.close();
    // print to the serial port too:
    Serial.println(dataString);
  }
  // if the file isn't open, pop up an error:
  else {
    Serial.println("error opening datalog.txt");
  }
}