#include <SPI.h> // include SPI library
#include <MFRC522.h> // include MFRC522 library
int RSTpin = 9; // reset pin for MFRC522
int SDApin = 10; // serial data pin
MFRC522 mfrc522(SDApin, RSTpin); // associate mfrc522 with MFRC522 library
MFRC522::MIFARE_Key key; // access key
byte blockData[16] = {"ABCDEFGHIJKLMNOP"}; // data to be written
// reset block to default value
//byte blockData[16] ={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
byte blockRead[18]; // to hold the read data
byte blocksz = sizeof(blockRead);
int block, sectorTrail, check;
void setup()
{
Serial.begin(9600); // define Serial output baud rate
SPI.begin(); // initialise SPI bus
mfrc522.PCD_Init(); // initialise mfrc522
for (byte i=0; i<6; i++) key.keyByte[i] = 0xFF; // access key set to HEX 0xFF
}
void loop()
{ // print message to Serial Monitor
Serial.println("Place card or tag beside MFRC522 reader");
while (!mfrc522.PICC_IsNewCardPresent())
{}; // do nothing but wait for a new card
mfrc522.PICC_ReadCardSerial(); // read card content
Serial.println("Enter block number"); // print message
while(Serial.available() == 0){} // no action until entry in serial buffer
while(Serial.available() >0) block = Serial.parseInt(); // get block number
if((block+1)%4==0 || block == 0) // check if block is sector trailer block
{ // print message to
Serial.print("Cannot write to block "); // Serial Monitor
Serial.println(block); // return to start of void loop()
return;
}
writeBlock(block, blockData); // function to write data
Serial.print("\nFinished writing to block "); // print message
Serial.println(block);
for (block=0; block<64; block++) // display content of non-sector
{ // trailer blocks
if((block+1) % 4 !=0 && block !=0) // non-sector trailer blocks
{
readBlock(block, blockRead); // function to read data
Serial.print("\nBlock "); // print block number
Serial.print(block);Serial.print("\t");
for (int i=0 ; i<16 ; i++) Serial.write(blockRead[i]);
} // print block data
}
Serial.println("\n\nFinished rea ding blocks"); // print message
Serial.println("Enter 1 to continue writing to a card or tag");
while(Serial.available() == 0) { } // no action until entry to serial buffer
// extract integer from serial buffer
while(Serial.available()>0) check=Serial.parseInt();
mfrc522.PCD_StopCrypto1(); // stop communication to card or tag
}
void writeBlock (int block, byte blockData[]) // function to write to block
{
sectorTrail = 3+4*(block/4);
check = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A,
sectorTrail, &key, &(mfrc522.uid));
if (check != MFRC522::STATUS_OK)
Serial.println(mfrc522.GetStatusCodeName(check));
check = mfrc522.MIFARE_Write(block, blockData, 16);
if (check != MFRC522::STATUS_OK)
Serial.println(mfrc522.GetStatusCodeName(check));
}
void readBlock (int block, byte blockRead[]) // function to read block
{
sectorTrail = 3+4*(block/4);
check = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A,
sectorTrail, &key, &(mfrc522.uid));
if (check != MFRC522::STATUS_OK)
Serial.println(mfrc522.GetStatusCodeName(check));
check = mfrc522.MIFARE_Read(block, blockRead, &blocksz);
if (check != MFRC522::STATUS_OK)
Serial.println(mfrc522.GetStatusCodeName(check));
}