/**
 * @brief Converted RFID Tag Arduino code
 * @author Michael Burmeister
 * @date February 10, 2018
 * @version 1.0
 * 
*/

#include "simpletools.h"
#include "fdserial.h"

//Forward Functions defines
void setup(void);
void loop(void);
char rfidRead(uint8_t *, uint8_t);
char rfidWrite(uint8_t , uint8_t *);
char rfidLogin(uint8_t *);
char rfidSetPass(uint8_t *, uint8_t *);
char rfidProtect(uint8_t enable);
char rfidReset(void);
char rfidReadLegacy(uint8_t *);
void rfidFlush(void);
void PrintHex(uint8_t *, uint8_t);


#define rxPin      11  // Serial input (connects to the RFID's SOUT pin)
#define txPin      10  // Serial output (connects to the RFID's SIN pin)

#define BUFSIZE    12  // Size of receive buffer (in bytes) for incoming data from the RFID R/W Module (this should be adjusted to be larger than the expected response)

// RFID R/W Module Commands
// Number of bytes returned in ()
#define RFID_Read         0x01	  // Read data from specified address, valid locations 1 to 33 (5)
#define RFID_Write	  0x02	  // Write data to specified address, valid locations 3 to 31 (1)
#define RFID_Login	  0x03	  // Login to tag with password (1)
#define RFID_SetPass      0x04	  // Change tag's password from old to new (1)
#define RFID_Protect	  0x05	  // Enable/disable password protection (1)
#define RFID_Reset        0x06	  // Reset tag (1)
#define RFID_ReadLegacy   0x0F	  // Read unique ID from EM4102 read-only tag (for backwards compatibility with Parallax RFID Card Reader #28140) (12)

// Memory map/address locations for EM4x50 tag
// Each address holds/returns a 32-bit (4 byte) value
#define ADDR_Password     0	  // Password (not readable)
#define ADDR_Protect	  1	  // Protection Word
#define ADDR_Control	  2	  // Control Word
// ADDR 3-31 are User EEPROM area
#define ADDR_Serial	  32	  // Device Serial Number
#define ADDR_DeviceID	  33	  // Device Identification

// Status/error return codes
#define ERR_OK		  0x01	  // No errors
#define ERR_LIW		  0x02	  // Did not find a listen window
#define ERR_NAK		  0x03	  // Received a NAK, could be invalid command
#define ERR_NAK_OLDPW	  0x04	  // Received a NAK sending old password (RFID_SetPass), could be incorrect password
#define ERR_NAK_NEWPW	  0x05	  // Received a NAK sending new password (RFID_SetPass)
#define ERR_LIW_NEWPW	  0x06	  // Did not find a listen window after setting new password (RFID_SetPass)
#define ERR_PARITY	  0x07	  // Parity error when reading data

// For use with RFID_ReadLegacy command
#define LEGACY_StartByte  0x0A
#define LEGACY_StopByte   0x0D
#define IN 1
#define OUT 0

//set_direction(11,  IN); Not needed
//set_direction(10, OUT); Not needed

fdserial *rfidSerial;


int main()
{
  // set up a new serial port
  //SoftwareSerial rfidSerial =  SoftwareSerial(rxPin, txPin);
  rfidSerial = fdserial_open(rxPin, txPin, FDSERIAL_MODE_NONE, 9600);
  setup();
  
  loop();
 
  while(1)
  {
    // Add main loop code here.
    
  }  
}

void setup()  // Set up code called once on start-up
{
  // define pin modes
 
  //while (!serial);   // wait until ready
  print("\n\nParallax RFID Read/Write Module\n");
  
  // set the baud rate for the SoftwareSerial port
  //rfidSerial.begin(9600);
  
  //flush();   // wait for all bytes to be transmitted to the Serial Monitor
}

void loop()  // Main code, to run repeatedly
{
  char idx;
  uint8_t rfidData[BUFSIZE];  // Buffer for incoming data
  
  /* 
    Code blocks can be commented/uncommented/rearranged to experiment with the available
    features and operations of the Parallax RFID Read/Write Module
  */   
  
  print("Reading tag's unique serial number...");
  while (rfidRead(rfidData, ADDR_Serial) != 0);
  PrintHex(rfidData, 4);   // The rfidData string should now contain the tag's serial number, so display it on the Serial Monitor
//  println();
  print("\n");
//  flush();
 
  print("Writing and verifying data to tag...");
  while (rfidWrite(3, (uint8_t*)"\xFE\xED\xFA\xCE") != 0);  // Write specified bytes into address 3 (user EEPROM area)
//  println("Done!");
    print("Done!\n");
//  flush();
 
  print("Reading tag's entire memory contents:\n");
  for (idx = 1; idx <= 33; idx++) // For each valid address location
  {
    while (rfidRead(rfidData, idx) != 0); // Read the data  
//    print(idx, DEC);
    print("%d", idx);
    print(": ");
    PrintHex(rfidData, 4);   // The rfidData string should now contain the data from the specific address, so display it on the Serial Monitor
//    println();
    print("\n");
//    flush();
  }

  // Login is only required to take advantage of the password protection features
  // For example, to set the tag's password, lock/unlock the tag, or read/write the tag (if the tag is locked)
  print("Logging into the tag...");
  while (rfidLogin((uint8_t*)"\x00\x00\x00\x00") != 0);  // Login to tag with default password of 0x00000000
//  println("Done!");
    print("Done!\n");
//  flush();

/*  Serial.print("Changing the tag's password...");
  while (rfidSetPass((uint8_t*)"\x00\x00\x00\x00", (uint8_t*)"\x00\x00\x00\x00") != 0);  // Change password from current (0x00000000) to new (0x00000000)
  serial.println("Done!");
  serial.flush();

  print("Locking tag...");
  while (rfidProtect(true) != 0);  // Enable read/write password protection of the entire tag
  println("Done!");
  flush();

  print("Unlocking tag...");
  while (rfidProtect(false) != 0);  // Enable read/write password protection of the entire tag
  println("Done!");
  flush();

  print("Resetting the tag...");
  while (rfidReset() != 0);  // Log out and reset the tag (will require a re-login if trying to access a locked tag after this point)
  println("Done!");
  flush(); */

/*print("Reading legacy tag's unique serial number...");  // Read unique ID from EM4102 read-only tag (used with the Parallax RFID Card Reader #28140)
  while (rfidReadLegacy(rfidData) != 0);
  println((char*)rfidData);   // The rfidData string should now contain the tag's unique ID with a null termination, so display it on the Serial Monitor
  flush();*/
 
  while(1);  // Stay here when the demonstration is over
  
}

/*** SUPPORTING FUNCTIONS ***/

char rfidRead(uint8_t *data, uint8_t address)
{
  char offset;  // offset into buffer
  
  rfidFlush();  // empties any buffered incoming serial data
  
//  rfidSerial.print("!RW");       // header
//  rfidSerial.write(RFID_Read);   // command
//  rfidSerial.write(address);     // address
  dprint(rfidSerial, "!RW");
  fdserial_txChar(rfidSerial, RFID_Read);
  fdserial_txChar(rfidSerial, address);
      
//  while (rfidSerial.available() != 5);  // wait until data is received from RFID module
  while (fdserial_rxCount(rfidSerial) != 5);
  
//  if (rfidSerial.read() == ERR_OK)  // if our status byte is OK
  if (fdserial_rxChar(rfidSerial) == ERR_OK)
  {
    for (offset = 0; offset < 4; offset++)
//      data[offset] = rfidSerial.read();  // get the remaining data
      data[offset] = fdserial_rxChar(rfidSerial);
       
    return 0; // return good
  }
  
  return -1; // return error
}


char rfidWrite(uint8_t address, uint8_t *data)
{
  char offset;  // offset into buffer
  
  rfidFlush();  // empties any buffered incoming serial data

//  rfidSerial.print("!RW");        // header
//  rfidSerial.write(RFID_Write);   // command
//  rfidSerial.write(address);      // address
  dprint(rfidSerial, "!RW");
  fdserial_txChar(rfidSerial, RFID_Write);
  fdserial_txChar(rfidSerial, address);
  
  for (offset = 0; offset < 4; offset++)
    //rfidSerial.write(data[offset]);     // data (4 bytes) 
    fdserial_txChar(rfidSerial, data[offset]);
    
//  while (rfidSerial.available() == 0); // wait until data is received from RFID module
  while (fdserial_rxCount(rfidSerial) == 0);
  
//  if (rfidSerial.read() == ERR_OK) // if our status byte is OK
  if (fdserial_rxChar(rfidSerial) == ERR_OK)
    return 0; // return good
  
  return -1; // return error
}


char rfidLogin(uint8_t *password)
{
  char offset;  // offset into buffer
  
  rfidFlush();  // empties any buffered incoming serial data
  
//  rfidSerial.print("!RW");        // header
//  rfidSerial.write(RFID_Login);   // command
  dprint(rfidSerial, "!RW");
  fdserial_txChar(rfidSerial, RFID_Login);
  for (offset = 0; offset < 4; offset++)
//    rfidSerial.write(password[offset]);     // password (4 bytes) 
    fdserial_txChar(rfidSerial, password[offset]);
  
//  while (rfidSerial.available() == 0); // wait until data is received from RFID module
  while (fdserial_rxCount(rfidSerial) == 0);
  
//  if (rfidSerial.read() == ERR_OK) // if our status byte is OK
  if (fdserial_rxChar(rfidSerial) == ERR_OK)
    return 0; // return good
  
  return -1; // return error
}


char rfidSetPass(uint8_t *currentpass, uint8_t *newpass)
{
  char offset;  // offset into buffer
  
  rfidFlush();  // empties any buffered incoming serial data
  
//  rfidSerial.print("!RW");          // header
//  rfidSerial.write(RFID_SetPass);   // command
  dprint(rfidSerial, "!RW");
  fdserial_txChar(rfidSerial, RFID_SetPass);
  
  for (offset = 0; offset < 4; offset++)
//    rfidSerial.write(currentpass[offset]);  // current password (4 bytes) 
    fdserial_txChar(rfidSerial, currentpass[offset]);
  for (offset = 0; offset < 4; offset++)
//    rfidSerial.write(newpass[offset]);      // new password (4 bytes) 
    fdserial_txChar(rfidSerial, newpass[offset]);
    
//  while (rfidSerial.available() == 0); // wait until data is received from RFID module
  while (fdserial_rxCount(rfidSerial) == 0);
  
//  if (rfidSerial.read() == ERR_OK) // if our status byte is OK
  if (fdserial_rxChar(rfidSerial) == ERR_OK)
    return 0; // return good
  
  return -1; // return error
}


char rfidProtect(uint8_t enable)
{
  rfidFlush();  // empties any buffered incoming serial data
  
//  rfidSerial.print("!RW");          // header
//  rfidSerial.write(RFID_Protect);   // command  
  dprint(rfidSerial, "!RW");
  fdserial_txChar(rfidSerial, RFID_Protect);
  
  if (enable == 0)              // flag
//    rfidSerial.write((byte)0);
    fdserial_txChar(rfidSerial, 0);
  else
//    rfidSerial.write((byte)1);
    fdserial_txChar(rfidSerial, 1);
  
//  while (rfidSerial.available() == 0); // wait until data is received from RFID module
  while (fdserial_rxCount(rfidSerial) == 0);

//  if (rfidSerial.read() == ERR_OK) // if our status byte is OK
  if (fdserial_rxChar(rfidSerial) == ERR_OK)
    return 0; // return good
  
  return -1; // return error    
}


char rfidReset()
{
  rfidFlush();  // empties any buffered incoming serial data
  
//  rfidSerial.print("!RW");        // header
//  rfidSerial.write(RFID_Reset);   // command  
  dprint(rfidSerial, "!RW");
  fdserial_txChar(rfidSerial, RFID_Reset);
  
//  while (rfidSerial.available() == 0); // wait until data is received from RFID module
  while (fdserial_rxCount(rfidSerial) == 0);

//  if (rfidSerial.read() == ERR_OK) // if our status byte is OK
  if (fdserial_rxChar(rfidSerial) == ERR_OK)
    return 0; // return good
  
  return -1; // return error    
}


char rfidReadLegacy(uint8_t *data)
{
  char offset;  // offset into buffer
  
  rfidFlush();  // empties any buffered incoming serial data
  
//  rfidSerial.print("!RW");             // header
//  rfidSerial.write(RFID_ReadLegacy);   // command
  dprint(rfidSerial, "!RW");
  fdserial_txChar(rfidSerial, RFID_ReadLegacy);
    
//  while (rfidSerial.available() != 12);  // wait until data is received from RFID module
  while (fdserial_rxCount(rfidSerial) != 12);
  
//  if (rfidSerial.read() == LEGACY_StartByte)  // if our start byte is OK
  if (fdserial_rxChar(rfidSerial) == LEGACY_StartByte)
  {
    for (offset = 0; offset < 10; offset++)
//      data[offset] = rfidSerial.read();  // get the remaining data
      data[offset] = fdserial_rxChar(rfidSerial);
       
    data[offset] = 0;  // null terminate the string of bytes we just received   
    return 0; // return good
  }
  
  return -1; // return error
}


void rfidFlush()  // Empties any buffered incoming serial data
{
//    while (rfidSerial.available() > 0)
//      rfidSerial.read();
  fdserial_rxFlush(rfidSerial);
}


// from http://forum.arduino.cc/index.php?topic=38107#msg282343
void PrintHex(uint8_t *data, uint8_t length) // prints 8-bit data in hex
{
  char tmp[length*2+1];
  uint8_t first ;
  int j=0;
  for (uint8_t i=0; i<length; i++) 
  {
    first = (data[i] >> 4) | 48;
    if (first > 57) tmp[j] = first + 39;
    else tmp[j] = first ;
    j++;

    first = (data[i] & 0x0F) | 48;
    if (first > 57) tmp[j] = first + 39; 
    else tmp[j] = first;
    j++;
  }
  tmp[length*2] = 0;
  print(tmp);
}