CarEngineDatalogger.pde

/**
 * CarEngineDatalogger
 *
 * Reads engine management system data using an OBD-II interface and
 * GPS data from a Locosys LS20031 module, and writes the values to a
 * USB memory stick using a VDIP1 module from FTDI.
 *
 * This implementation relies on the extra UARTs available in an
 * Arduino Mega. It could alternatively use SoftwareSerial and run on
 * a Duemilanove or similar, but there may be problems with maintaining
 * several serial ports running at moderately high speed simultaneously.
 *
 * Serial connections are:
 *   Serial  = host computer           38400bps
 *   Serial1 = OBD-II interface        38400bps
 *   Serial2 = GPS module              57600bps
 *   Serial3 = Vinculum flash storage   9600bps
 *
 * Copyright 2009 Jonathan Oxer <jon@oxer.com.au>
 * Copyright 2009 Hugh Blemings <hugh@blemings.org>
 * http://www.practicalarduino.com/projects/car-engine-datalogger
 */

// Include the floatToString helper
#include "floatToString.h"

// Use the TinyGPS library to parse GPS data
#include <TinyGPS.h>
TinyGPS gps;

// We need the PString library to create a log buffer
#include <PString.h>

#define ledPin 13
//char incomingByte;  // for incoming serial data

// Host serial connection setup
#define HOST Serial
byte logActive = 0;

// OBD-II interface setup
#define OBD Serial1

// GPS module setup
#define GPS Serial2

// Vinculum setup
#define FLASH Serial3        // Serial port for VDIP connection
#define FLASH_RESET      12  // Pin for reset of VDIP module (active low)
#define FLASH_STATUS_LED 11  // LED to show whether a file is open
#define FLASH_WRITE_LED  10  // LED to show when write is in progress
#define FLASH_RTS_PIN     9  // Check if the VDIP is ready to receive. Active low

// Digital pin connected to the "log" status LED (active high)
#define LOG_LED 4
#define LOG_BUTTON 3
#define LOG_BUTTON_INT 1
#define POWER_SENSE_PIN 2
#define POWER_SENSE_INT 0
volatile unsigned long logButtonTimestamp = 0;

//void gpsdump(TinyGPS &gps);
//bool feedgps();
void printFloat( double f, int digits=2 );
//char * floatToString(char * outstr, float value, int places, int minwidth=0, bool rightjustify=false);


/**
 * Initial configuration
 */
void setup() {
  pinMode(ledPin, OUTPUT);
  HOST.begin(38400);      // Port for connection to host
  HOST.println("Car Engine Datalogger starting up");

  pinMode(LOG_LED, OUTPUT);
  digitalWrite(LOG_LED, LOW);
  pinMode(LOG_BUTTON, INPUT);
  digitalWrite(LOG_BUTTON, HIGH);

  // Set up the GPS device
  HOST.print(" * Initialising GPS             ");
  GPS.begin(57600);       // Port for connection to GPS module
  HOST.println("[OK]");

  // Set up the OBD-II interface
  /* HOST.print(" * Initialising OBD-II          ");
  OBD.begin(38400);       // Port for connection to OBD adaptor
  configureObdAdapter();  // Set options in the OBD adapter
  HOST.println("[OK]"); */

  // Set up the Vinculum flash storage device
  HOST.print(" * Initialising flash storage   ");
  pinMode(FLASH_STATUS_LED, OUTPUT);
  digitalWrite(FLASH_STATUS_LED, HIGH);

  pinMode(FLASH_WRITE_LED, OUTPUT);
  digitalWrite(FLASH_WRITE_LED, LOW);

  pinMode(FLASH_RTS_PIN, INPUT);

  pinMode(FLASH_RESET, OUTPUT);
  digitalWrite(FLASH_RESET, LOW);
  digitalWrite(FLASH_STATUS_LED, HIGH);
  digitalWrite(FLASH_WRITE_LED, HIGH);
  delay( 100 );
  digitalWrite(FLASH_RESET, HIGH);
  delay( 100 );
  FLASH.begin(9600);      // Port for connection to Vinculum flash memory module
  FLASH.print("IPA");     // Sets the VDIP to ASCII mode
  FLASH.print(13, BYTE);

  digitalWrite(FLASH_STATUS_LED, LOW);
  digitalWrite(FLASH_WRITE_LED, LOW);
  HOST.println("[OK]");
  
  // Interrupt triggered by pressing "log on/off" button
  attachInterrupt(1, modeButton, FALLING);
  
  // Interrupt triggered by falling voltage on power supply input
  attachInterrupt(0, powerFail, FALLING);
}


/**
 * Main program loop
 */
void loop()
{
  // Process any commands from the host
  processHostCommands();
  
  // Echo data from flash back to the host
  processFlashBuffer();

  // Only do stuff if we're in logging mode
  if( logActive == 1 )
  {
    if( feedgps() )  // Only do a log write if we have GPS data
    {
      // Log entry columns:
      // Date, Time, Lat, Lon, Altitude (m), Speed (km/h)

      digitalWrite(FLASH_WRITE_LED, HIGH);  // Indicate that we're taking a log reading

      // Set up an 80-character buffer for writing to the memory stick
      char flashBuffer[80];
      PString logEntry( flashBuffer, sizeof( flashBuffer ) ); // Create a PString object called logEntry
      char valBuffer[15]; // Buffer for converting floats to strings before appending to flashBuffer
            
      /////////////////////// ACQUIRE GPS DAT //////////////////////////////
      //HOST.println("Acquired Data");
      //HOST.println("-------------");
      //gpsdump(gps);
      //HOST.println("-------------");
      float fLat, fLon;
      unsigned long age, date, time, chars;
      int year;
      byte month, day, hour, minute, second, hundredths;
      //unsigned short sentences, failed;

      gps.f_get_position( &fLat, &fLon, &age );
      gps.get_datetime( &date, &time, &age );
      gps.crack_datetime( &year, &month, &day, &hour, &minute, &second, &hundredths, &age );
      
      // Date (yyyy-m-d, but *should* be yyyy-mm-dd)
      floatToString(valBuffer, year, 0);
      logEntry += valBuffer;
      logEntry += "-";
      floatToString(valBuffer, static_cast<int>(month), 0);
      logEntry += valBuffer;
      logEntry += "-";
      floatToString(valBuffer, static_cast<int>(day), 0);
      logEntry += valBuffer;
      logEntry += ",";
      
      // Time (hours:minutes:seconds.hundredths)
      floatToString(valBuffer, static_cast<int>(hour), 0);
      logEntry += valBuffer;
      logEntry += ":";
      floatToString(valBuffer, static_cast<int>(minute), 0);
      logEntry += valBuffer;
      logEntry += ":";
      floatToString(valBuffer, static_cast<int>(second), 0);
      logEntry += valBuffer;
      logEntry += ".";
      floatToString(valBuffer, static_cast<int>(hundredths), 0);
      logEntry += valBuffer;
      logEntry += ",";
      
      // Latitude
      floatToString(valBuffer, fLat, 5);
      logEntry += valBuffer;
      logEntry += ",";

      // Longitude
      floatToString(valBuffer, fLon, 5);
      logEntry += valBuffer;
      logEntry += ",";
      
      // Altitude (meters)
      floatToString(valBuffer, gps.f_altitude(), 2);
      logEntry += valBuffer;
      logEntry += ",";
      
      // Speed (km/h)
      floatToString(valBuffer, gps.f_speed_kmph(), 2);
      logEntry += valBuffer;
      //logEntry += ",";

      /////////////////////// ACQUIRE OBD DATA //////////////////////////////
      //byte mode = 0x0;
      //byte parameter = 0x0;
      
      /* HOST.println( "Getting RPM reading" );
      mode = 0x01;
      parameter = 0x0C;
      getObdValue( mode, parameter );
      HOST.println("done");
      delay( 100 ); */
      
      
      HOST.println( "Getting speed reading" );
      char pid[] = "010C";
      //getObdValue( pid, logEntry );
      HOST.println("done");
      
      //delay( 5000 );
      /*
      while( OBD.available() > 0 )
      {
        incomingByte = OBD.read();
        readChar = (byte)incomingByte;
        //response = readChar;
        if((incomingByte == 0x3E) || (incomingByte == 0x0D))   // The hex value for the ">" prompt returned by the ELM327
        {
          HOST.println();
        } else {
          HOST.print(readChar);
        }
      }
      */

      /////////////////////// WRITE TO FLASH //////////////////////////////
      //int logEntryLength = logEntry.length();
      byte position = 0;
      
      /*HOST.print(logEntry.length());
      HOST.print(": ");
      HOST.println(logEntry); */
      
      FLASH.print("WRF ");
      FLASH.print(logEntry.length() + 1);  // 1 extra for the newline
      FLASH.print(13, BYTE);
      
      while(position < logEntry.length())
      {
        if(digitalRead(FLASH_RTS_PIN) == LOW)
        {
          FLASH.print(flashBuffer[position]);
          position++;
        } else {
          HOST.println("BUFFER FULL");
        }
      }
      
      FLASH.print(13, BYTE);               // End the log entry with a newline
      digitalWrite(FLASH_WRITE_LED, LOW);

      
      /*if(digitalRead(FLASH_RTS_PIN) == HIGH)
      {
        HOST.println("Oops, it's high");
      } */
      delay( 100 );  // Delay only if we've written a log entry
    }
  }
}