CO2SensorStore.ino

#include "SoftwareSerial.h"
SoftwareSerial K_30_Serial(12,13);  //Sets up a virtual serial port. Using pin 12 for Rx and pin 13 for Tx
                                    
byte readCO2[] = {0xFE, 0X44, 0X00, 0X08, 0X02, 0X9F, 0X25};  //Command packet to read Co2 (see app note)
byte response[] = {0,0,0,0,0,0,0};  //create an array to store the response

//multiplier for value. default is 1. set to 3 for K-30 3% and 10 for K-33 ICB
int valMultiplier = 1;
#include <Wire.h>
#include "SparkFunMPL3115A2.h"
#include <SPI.h>
#include <SD.h>
MPL3115A2 myPressure;
const int chipSelect = 10;

File myFile;

void setup() // put your setup code here, to run once:
{
  Serial.begin(9600);         //Opens the main serial port to communicate with the computer

  K_30_Serial.begin(9600);    //Opens the virtual serial port with a baud of 9600  
  myPressure.begin(); // Get sensor online
  myPressure.setModeAltimeter(); // Measure altitude above sea level in meters
  myPressure.setOversampleRate(7); // Set Oversample to the recommended 128
  myPressure.enableEventFlags(); // Enable all three pressure and temp event flags 
  Serial.print("Initializing SD card...");
 
  if (SD.exists("example.txt")) 
  {
    Serial.println("example.txt exists.");
  } else 
  {
    Serial.println("example.txt doesn't exist.");
  }
    Serial.println("Creating example.txt...");
  myFile = SD.open("example.txt", FILE_WRITE);
  myFile.close();

}

void loop() 
{
  sendRequest(readCO2);
  unsigned long valCO2 = getValue(response);
  Serial.print("Co2 ppm = ");
  Serial.println(valCO2);
  delay(2000);
  
  float altitude = myPressure.readAltitudeFt();
  Serial.print(" Altitude(ft):");
  Serial.print(altitude, 2);
  float pressure = myPressure.readPressure();
  Serial.print("Pressure(Pa):");
  Serial.print(pressure, 2);

  float temperature = myPressure.readTempF();
  Serial.print(" Temp(f):");
  Serial.print(temperature, 2);

  Serial.println();
  // make a string for assembling the data to log:
  String dataString = "";

  // read three sensors and append to the string:
  for (int analogPin = 0; analogPin < 3; analogPin++) 
  {
    int sensor = analogRead(analogPin);
    dataString += String(sensor);
    if (analogPin < 2) {
      dataString += ","; 
    }
  }
File dataFile = SD.open("datalog.txt", FILE_WRITE);

  // if the file is available, write to it:
  if (dataFile) 
  {
    dataFile.println(dataString);
    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");
  }


  delay(2000);
  
  }

void sendRequest(byte packet[])
{
  while(!K_30_Serial.available())  //keep sending request until we start to get a response
  {
    K_30_Serial.write(readCO2,7);
    delay(50);
  }
  
  int timeout=0;  //set a timeoute counter
  while(K_30_Serial.available() < 7 ) //Wait to get a 7 byte response
  {
    timeout++;  
    if(timeout > 10)    //if it takes to long there was probably an error
      {
        while(K_30_Serial.available())  //flush whatever we have
          K_30_Serial.read();
          
          break;                        //exit and try again
      }
      delay(50);
  }
  
  for (int i=0; i < 7; i++)
  {
    response[i] = K_30_Serial.read();
  }  
}

unsigned long getValue(byte packet[])
{
    int high = packet[3];                        //high byte for value is 4th byte in packet in the packet
    int low = packet[4];                         //low byte for value is 5th byte in the packet
   unsigned long val = high*256 + low;                //Combine high byte and low byte with this formula to get value
    return val* valMultiplier;
}