#include <Wire.h>

#include "i2c.h"

#include "i2c_BMP280.h"

BMP280 bmp280;

#include <SPI.h>

#include <SD.h>

File myFile;

String filename = "test.csv";     //要寫入的檔案名稱

void setup() {

  pinMode(10,OUTPUT);             //保留pin10, SD Library需要使用

  while (!SD.begin(4)) {}

  Serial.begin(9600);

  bmp280.initialize();

  bmp280.setEnabled(0);

  bmp280.triggerMeasurement();

}

void loop()

{

  bmp280.awaitMeasurement();

  float temperature;             //氣溫，單位：攝氏溫度

  bmp280.getTemperature(temperature);

  float pascal;                  //氣壓，單位：pa帕

  bmp280.getPressure(pascal);

  float meters;                  //海拔高度，單位：m公尺

  bmp280.getAltitude(meters);    //假設海平面大氣壓為101325Pa，所計算的海拔高度;

  bmp280.triggerMeasurement();

  Serial.print(meters);

  Serial.println();

  float timesec= millis()/1000.0;           //目前時間，單位是"秒"

  char timesecstr[6];

  dtostrf(timesec,3, 3, timesecstr);   

  myFile = SD.open(filename, FILE_WRITE);

  if (myFile) {

    Serial.print("Writing to test.csv...");

    myFile.print(timesecstr);              //寫入 時間 

    myFile.print(",");                  //之後每個數據之間加入逗號","

    myFile.print(meters);                //寫入 海拔高度

    myFile.println();

    myFile.close();                     //關閉檔案

    Serial.println("done.");

  } else {

    Serial.println("error opening test.csv");

  }

}