Arduino Sketch to create 256Kb log files

#include <SdFat.h>
#include <Time.h>

SdFat sd;

#define DEBUG

#define SD_CHIPSELECT 9
#define MAX_FILESIZE 262144

SdFile logFile;
char name[] = "LOG00000.BIN";

unsigned long lastCommunication, lastCapture = 0;

void setup() {
  Serial.begin(57600);

  setSyncProvider(requestSync);
  setSyncInterval(300);

  if (!sd.init(SPI_FULL_SPEED, SD_CHIPSELECT)) sd.initErrorHalt();

  delay(5000);

  createLogFile();
}

void loop() {
  processPacket();

  if (timeStatus() != timeNotSet) {
    if ((lastCapture == 0) || (millis() - lastCapture >= 60000UL)) {
      logEvent();
    } else if (millis() - lastCapture <= 30000UL) {
      sendFile();
    } // ((lastCapture == 0) || (millis() - lastCapture >= 60000UL))
  } else { // (timeStatus() != timeNotSet)
    Serial.write(0x02); // 0x02 = Sync Clock
    Serial.write('\r');
    Serial.write('\n');
    delay(1000);
  } // (timeStatus() != timeNotSet)
}

time_t requestSync() {
  Serial.write(0x01); // 0x01 = Sync clock
  Serial.write('\r');
  Serial.write('\n');
  return 0; // the time will be sent later in response to serial mesg
}

void processPacket() {
  // if time sync available from serial port, update time and return true
  while(Serial.available() >= 11 ){  // time message consists of a header and ten ascii digits
    lastCommunication = millis();
    byte c = Serial.read();
    if (c == 'T') {
      time_t pctime = 0;
      for (byte i=0; i < 11 -1; i++){
        c = Serial.read();
        if( c >= '0' && c <= '9'){
          pctime = (10 * pctime) + (c - '0') ; // convert digits to a number
        }
      }
      setTime(pctime);   // Sync Arduino clock to the time received on the serial port
    }
  }
}

void createLogFile(void) {
  #ifdef DEBUG
  Serial.println("Creating LOG File");
  #endif
  if (logFile.isOpen()) {
    logFile.close();
  }
  for (uint16_t i = 0; i < 100000; i++) {
    name[3] = i/10000 + '0';
    name[4] = i/1000 + '0';
    name[5] = i/100 + '0';
    name[6] = i/10 + '0';
    name[7] = i%10 + '0';
    // O_CREAT - create the file if it does not exist
    // O_EXCL - fail if the file exists
    // O_WRITE - open for write
    if (logFile.open(name, O_CREAT | O_EXCL | O_WRITE)) {
      #ifdef DEBUG
      Serial.print("Criado:");
      Serial.println(name);
      #endif
      break;
    } else {
      if (logFile.open(name, O_WRITE | O_APPEND | O_CREAT)) {
        if (name[0] == 'L' && name[1] == 'O' && name[2] == 'G') {
          #ifdef DEBUG
          Serial.print("Aberto:");
          Serial.print(name);
          Serial.print(" com ");
          Serial.print(logFile.fileSize());
          Serial.println(" bytes.");
          #endif
          if (!(logFile.fileSize() > MAX_FILESIZE)) {
            #ifdef DEBUG
            Serial.println("Usando arquivo < 256Kb que foi encontrado.");
            #endif
            break;
          } else {
            logFile.close();
          }
        }
      }
    }
  }
  if (!logFile.isOpen()) sd.errorHalt_P(PSTR("opening log for write failed"));
}

void logEvent() {
  if (!logFile.isOpen()) sd.errorHalt_P(PSTR("log is not opened"));
  lastCapture = millis();
  #ifdef DEBUG
  Serial.println("Logging 64 bytes...");
  #endif
  logFile.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 64);
  logFile.sync();
  #ifdef DEBUG
  Serial.println("Finished logging and syncing 64 bytes...");
  #endif
  checkLogSize();
}

void checkLogSize() {
  if (logFile.fileSize() > MAX_FILESIZE) {
    #ifdef DEBUG
    Serial.println("Atingido limite de 256Kb, criando outro arquivo...");
    #endif
    createLogFile();
  }
}

void sendFile() {
  SdFile sentFile;
  char currentFile[13];
  char filename[13];
  byte buffer[100];
  byte c;
  byte i;
  int checksum;

  #ifdef DEBUG
  Serial.println("Trying to send file");
  #endif

  Serial.write(0x03); // 0x03 = Request to send a file
  Serial.write('\r');
  Serial.write('\n');
  delay(1000);
  if (Serial.available() == 1) {
    lastCommunication = millis();
    byte ch = Serial.read();
    #ifdef DEBUG
    Serial.print("Received: ");
    Serial.println(ch, HEX);
    #endif
    if (ch == 0xff) { // 0xff = ACK
      logFile.getFilename(currentFile);
      while (sentFile.openNext(sd.vwd(), O_READ)) {
        sentFile.getFilename(filename);
        if (filename[0] == 'L' && filename[1] == 'O' && filename[2] == 'G') {
          if (strcmp(filename, currentFile) != 0) {
            #ifdef DEBUG
            Serial.print("Sending file ");
            Serial.println(filename);
            #endif
            //checksum = 0;
            //i = 0;
            while ((c = sentFile.read()) >= 0) {
              checksum ^= c;
              Serial.write(c);
              //buffer[i++] = c;
              //if (i == 100) {
              //  i = 0;
              //  Serial.write(buffer, sizeof(buffer));
              //}
            }
            //Serial.write(buffer, i);
            Serial.write('\r');
            Serial.write('\n');
            delay(1000);
            #ifdef DEBUG
            Serial.print("Generated checksum: ");
            Serial.println(checksum, HEX);
            #endif
            if (Serial.available() == 1) {
              lastCommunication = millis();
              ch = Serial.read();
              #ifdef DEBUG
              Serial.print("Received checksum: ");
              Serial.println(ch, HEX);
              #endif
              if (ch == checksum) {
                sd.remove(name);
                return;
              } // (ch == checksum)
            } // (Serial.available() == 1)
          } // (strcmp(name, currentFile) != 0)
        } // (name[0] == 'L' && name[1] == 'O' && name[2] == 'G')
        sentFile.close();
      } // while (sentFile.openNext(sd.vwd(), O_READ))
    } // (ch == 0xff)
  } // (Serial.available() == 1)
}