My first Arduino project - part 4

Checking the SD card

First I'll check whether the SD part of the Data Logging shield is working alright. This is described on this page.

The output I got was the following:

type any character to start


init time: 350


Card type: SD2


Manufacturer ID: 2
OEM ID: TM
Product: SD02G
Version: 4.8
Serial number: 371219368
Manufacturing date: 11/2009


cardSize: 3842048 (512 byte blocks)
flashEraseSize: 128 blocks
eraseSingleBlock: true


part,boot,type,start,length
1,0,6,137,3841911
2,0,0,0,0
3,0,0,0,0
4,0,0,0,0


Volume is FAT16
blocksPerCluster: 64
clusterCount: 60022
fatStartBlock: 138
fatCount: 2
blocksPerFat: 235
rootDirStart: 608
dataStartBlock: 640


type any character to start

To make the test work I had to put the baud rate to 9600 and I had to disconnect the connections to pin 0 of the Arduino (and the 5V line) to the RFID reader.  I've noticed that I have to disconnect the RFID reader each time I need to upload a sketch.  I'm currently still looking how to connect the RFID reader to something else than Digital pin 0 (which is also the RX pin used to transfer sketches to the Arduino).

But luckely my SD card seems to be OK :-)

The uses for the SD card

One way to use the SD card is to add a log entry each the time a token is read (one that's different than the previous one).

The second use for the SD card would be to keep track of all allowed users on the SD card.  Not only the token gets logged when read, it also gets checked against a list of tokens that are allowed access.  Only when access is allowed, the green LED should light up (simulating the door lock unlocking). 

Logging access

This blog will only cover writing a log entry to a log file whenever a valid token is read.  Validating the read token will be dealt with in my next blog entry.

I manually created 2 directories on the SD-card, the 'logs' and 'admin' directories.

The 'logs' directory which will keep track of all the access log files. Eventually a new file should be created per day, this will allow easier cleanup of the log files.

The 'admin' directory will contain a commas separated value list of all members with there corresponding RFID token (members.csv). I will also keep track of subscription information in a file called 'subscript.csv'.  A last file I need is the 'loginfo.txt' which will keep track of the last log date and the number of days after the subscription ends before somebody is no longer allowed to access the weight room.

I have been going through the example code and copied whatever I needed to make my arduino log every valid token to the 'log.csv' file within the 'logs' directory. The one 'log.csv' file is temporary before working out how to rotate the log files.


#include <SdFat.h>
#include <Wire.h>
#include <RTClib.h>


int LED = 7;
int RFID_ENABLE = 2;
int CODE_SIZE = 10;
int ARRAY_SIZE = 11;


int bytesRead = 0;
char lastReadRFID[11];
char code[11];


//The RTC related object
RTC_DS1307 RTC;


//The SD card related objects
Sd2Card card;
SdVolume volume;
SdFile root;
SdFile accessLogDir;
SdFile adminDir;
SdFile logFile;




//===================================================================================
// SETUP METHOD
//===================================================================================
void setup() { 
  
  Serial.begin(2400);     // RFID reader SOUT pin connected to Serial RX pin at 2400bps 
  Wire.begin();
  RTC.begin();
  pinMode(RFID_ENABLE,OUTPUT);   // Set digital pin 2 as OUTPUT to connect it to the RFID /ENABLE pin 
  pinMode(LED, OUTPUT);   // Set digital pin 13 as OUTPUT to connect it to LED
  activateRFID();
  // initialize the SD card at SPI_FULL_SPEED for best performance.
  // try SPI_HALF_SPEED if bus errors occur.
  if (!card.init(SPI_FULL_SPEED)) Serial.println("card.init failed");


  // initialize a FAT volume
  if (!volume.init(&card)) Serial.println("volume.init failed");


  // open the root directory
  if (!root.openRoot(&volume)) Serial.println("openRoot failed");


  //open the logDir
  char logDirName[] = "logs";
  if (!accessLogDir.open(&root, logDirName, O_RDONLY)) {
    Serial.println("figure out error while opening logs and admin dir");
  }
  //open the admin
  char adminDirName[] = "admin";
  adminDir.open(&root, adminDirName, O_RDONLY);
  
}  


//===================================================================================
// MAIN APP LOOP
//===================================================================================
void loop() {
  openLogFile();
  if (!adminDir.isOpen()) {
    Serial.println ("admin dir not opened");
  }
  activateRFID();
  readRFID();
  if (bytesRead == CODE_SIZE) {
    deActivateRFID();
    handleReadRFID();
  }
  closeLogFile();
//  accessLogDir.close();
//  adminDir.close();
}


//===================================================================================
// close the log file
//===================================================================================
void closeLogFile() {
  logFile.close();
}


//===================================================================================
// opens the log file
//===================================================================================
void openLogFile() {
  if (!accessLogDir.isOpen()) {
    Serial.println ("access log dir not opened");
  } else {
    char name[] = "log.csv";
    logFile.open(&accessLogDir, name, O_CREAT | O_WRITE | O_APPEND);
    if (!logFile.isOpen()) {
      Serial.println ("file not opened");
    }
  }
}


//===================================================================================
// handle the read RFID tag
//===================================================================================
void handleReadRFID(){
//  if (code != lastReadRFID ) {
  if (codesAreDifferent() ) {
    Serial.print(RTC.now().year(), DEC);
    Serial.print('/');
    Serial.print(RTC.now().month(), DEC);
    Serial.print('/');
    Serial.print(RTC.now().day(), DEC);
    Serial.print(' ');
    Serial.print(RTC.now().hour(), DEC);
    Serial.print(':');
    Serial.print(RTC.now().minute(), DEC);
    Serial.print(':');
    Serial.print(RTC.now().second(), DEC);
    Serial.print("TAG code is: ");       // possibly a good TAG 
    Serial.print(code);                  // print the TAG code 
    Serial.print(" while old tag is ");  // print the TAG code 
    Serial.println(lastReadRFID);        // print the TAG code 
    //write to log file
    if (logFile.isOpen()) {
      logFile.print(RTC.now().year(), DEC);
      logFile.print('/');
      logFile.print(RTC.now().month(), DEC);
      logFile.print('/');
      logFile.print(RTC.now().day(), DEC);
      logFile.print(' ');
      logFile.print(RTC.now().hour(), DEC);
      logFile.print(':');
      logFile.print(RTC.now().minute(), DEC);
      logFile.print(':');
      logFile.print(RTC.now().second(), DEC);
      logFile.print(",");       // possibly a good TAG 
      logFile.println(code);                  // print the TAG code 
    }


    //
    deActivateRFID();
    digitalWrite(LED, HIGH);             // Switch on the LED
    delay(2000);                         // wait for 2 seconds
    setLastReadRFID();
    digitalWrite(LED, LOW);              // Switch off the LED
  } else {
    Serial.print("new (");               // possibly a good TAG 
    Serial.print(code);                  // print the TAG code 
    Serial.print(") equals new (");      // print the TAG code 
    Serial.print(lastReadRFID);          // print the TAG code 
    Serial.println(")");                 // print the TAG code 
  }
}


//===================================================================================
// checks wether the current code is different from the previously read code
//===================================================================================
boolean codesAreDifferent(){
  for (int i = 0; i < CODE_SIZE; i++) {
    if (code[i] != lastReadRFID[i]) {
      return true;
    }
  }
  return false;
}
  
//===================================================================================
// Activate the RFID reader
//===================================================================================
void activateRFID() {
    digitalWrite(RFID_ENABLE, LOW);// Activate the RFID reader
}
  
//===================================================================================
// DeActivate the RFID reader
//===================================================================================
void deActivateRFID() {
    digitalWrite(RFID_ENABLE, HIGH);// Deactivate the RFID reader
}
  
//===================================================================================
// read the code from the RFID reader
//===================================================================================
void readRFID(){
  bytesRead = 0;
  int val = 0;
    
  if(Serial.available() > 0) {          // if data available from reader 
    if((val = Serial.read()) == CODE_SIZE) {   // check for header 
      while(bytesRead<10) {              // read 10 digit code 
        if( Serial.available() > 0) { 
          val = Serial.read(); 
          if((val == 10)||(val == 13)) { // if header or stop bytes before the 10 digit reading 
            break;                       // stop reading 
          }
          code[bytesRead] = val;         // add the digit           
          bytesRead++;                   // ready to read next digit  
        } 
      } 
    }
  }
}


//===================================================================================
// set the lastReadRFID code
//===================================================================================
void setLastReadRFID(){
  for (int i = 0; i < CODE_SIZE; i++) {
    lastReadRFID[i] = code[i];        // copy the content of the last read RFID code into lastReadRFID
  }
  lastReadRFID[10] = 0;
  code[10] = 0;
}

Stats

compiler

Binary sketch size: 15736 bytes (of a 30720 byte maximum)

So I'm passing half of my capacity, let's see what I can still add.

knowledge

Seems like my knowledge of C (or my lack of it) is becoming a slight bottleneck.