I try these code and I have one problem.
The key B is diferent from Key A.
I have read the information but I don't write the new information.
"Authenticating again using key B...
PCD_Authenticate() failed: Error in communication."
Were I need to put the key B to use the Key B to write the data?
#include <SPI.h>
#include <MFRC522.h>
#define RST_PIN 9 // Configurable, see typical pin layout above
#define SS_PIN 10 // Configurable, see typical pin layout above
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance.
MFRC522::MIFARE_Key key;
/**
* Initialize.
*/
void setup() {
Serial.begin(9600); // Initialize serial communications with the PC
while (!Serial); // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
SPI.begin(); // Init SPI bus
mfrc522.PCD_Init(); // Init MFRC522 card
// Prepare the key (used both as key A and as key B)
// using FFFFFFFFFFFFh which is the default at chip delivery from the factory
{
key.keyByte[0] = 0x6c;
key.keyByte[1] = 0x8f;
key.keyByte[2] = 0x6f;
key.keyByte[3] = 0xa1;
key.keyByte[4] = 0x68;
key.keyByte[5] = 0xef;
}
Serial.println(F("Scan a MIFARE Classic PICC to demonstrate read and write."));
Serial.print(F("Using key (for A and B):"));
dump_byte_array(key.keyByte, MFRC522::MF_KEY_SIZE);
Serial.println();
Serial.println(F("BEWARE: Data will be written to the PICC, in sector #1"));
}
/**
* Main loop.
*/
void loop() {
// Look for new cards
if ( ! mfrc522.PICC_IsNewCardPresent())
return;
// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial())
return;
// Show some details of the PICC (that is: the tag/card)
Serial.print(F("Card UID:"));
dump_byte_array(mfrc522.uid.uidByte, mfrc522.uid.size);
Serial.println();
Serial.print(F("PICC type: "));
MFRC522::PICC_Type piccType = mfrc522.PICC_GetType(mfrc522.uid.sak);
Serial.println(mfrc522.PICC_GetTypeName(piccType));
// Check for compatibility
if ( piccType != MFRC522::PICC_TYPE_MIFARE_MINI
&& piccType != MFRC522::PICC_TYPE_MIFARE_1K
&& piccType != MFRC522::PICC_TYPE_MIFARE_4K) {
Serial.println(F("This sample only works with MIFARE Classic cards."));
return;
}
// In this sample we use the second sector,
// that is: sector #1, covering block #4 up to and including block #7
byte sector = 9;
byte blockAddr = 36;
byte dataBlock[] = {
0x88, 0x13, 0x00, 0x00, // 1, 2, 3, 4,
0x77, 0xec, 0xff, 0xff, // 5, 6, 7, 8,
0x88, 0x13, 0x00, 0x09, // 9, 10, 255, 12,
0x25, 0xda, 0x25, 0xda // 13, 14, 15, 16
};
byte trailerBlock = 39;
MFRC522::StatusCode status;
byte buffer[18];
byte size = sizeof(buffer);
// Authenticate using key A
Serial.println(F("Authenticating using key A..."));
status = (MFRC522::StatusCode) mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, trailerBlock, &key, &(mfrc522.uid));
if (status != MFRC522::STATUS_OK) {
Serial.print(F("PCD_Authenticate() failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
// Show the whole sector as it currently is
Serial.println(F("Current data in sector:"));
mfrc522.PICC_DumpMifareClassicSectorToSerial(&(mfrc522.uid), &key, sector);
Serial.println();
// Read data from the block
Serial.print(F("Reading data from block ")); Serial.print(blockAddr);
Serial.println(F(" ..."));
status = (MFRC522::StatusCode) mfrc522.MIFARE_Read(blockAddr, buffer, &size);
if (status != MFRC522::STATUS_OK) {
Serial.print(F("MIFARE_Read() failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
}
Serial.print(F("Data in block ")); Serial.print(blockAddr); Serial.println(F(":"));
dump_byte_array(buffer, 16); Serial.println();
Serial.println();
// Authenticate using key B
Serial.println(F("Authenticating again using key B..."));
status = (MFRC522::StatusCode) mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_B, trailerBlock, &key, &(mfrc522.uid));
if (status != MFRC522::STATUS_OK) {
Serial.print(F("PCD_Authenticate() failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
// Write data to the block
Serial.print(F("Writing data into block ")); Serial.print(blockAddr);
Serial.println(F(" ..."));
dump_byte_array(dataBlock, 16); Serial.println();
status = (MFRC522::StatusCode) mfrc522.MIFARE_Write(blockAddr, dataBlock, 16);
if (status != MFRC522::STATUS_OK) {
Serial.print(F("MIFARE_Write() failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
}
Serial.println();
// Read data from the block (again, should now be what we have written)
Serial.print(F("Reading data from block ")); Serial.print(blockAddr);
Serial.println(F(" ..."));
status = (MFRC522::StatusCode) mfrc522.MIFARE_Read(blockAddr, buffer, &size);
if (status != MFRC522::STATUS_OK) {
Serial.print(F("MIFARE_Read() failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
}
Serial.print(F("Data in block ")); Serial.print(blockAddr); Serial.println(F(":"));
dump_byte_array(buffer, 16); Serial.println();
// Check that data in block is what we have written
// by counting the number of bytes that are equal
Serial.println(F("Checking result..."));
byte count = 0;
for (byte i = 0; i < 16; i++) {
// Compare buffer (= what we've read) with dataBlock (= what we've written)
if (buffer[i] == dataBlock[i])
count++;
}
Serial.print(F("Number of bytes that match = ")); Serial.println(count);
if (count == 16) {
Serial.println(F("Success :-)"));
} else {
Serial.println(F("Failure, no match :-("));
Serial.println(F(" perhaps the write didn't work properly..."));
}
Serial.println();
// Dump the sector data
Serial.println(F("Current data in sector:"));
mfrc522.PICC_DumpMifareClassicSectorToSerial(&(mfrc522.uid), &key, sector);
Serial.println();
// Halt PICC
mfrc522.PICC_HaltA();
// Stop encryption on PCD
mfrc522.PCD_StopCrypto1();
}
/**
* Helper routine to dump a byte array as hex values to Serial.
*/
void dump_byte_array(byte *buffer, byte bufferSize) {
for (byte i = 0; i < bufferSize; i++) {
Serial.print(buffer[i] < 0x10 ? " 0" : " ");
Serial.print(buffer[i], HEX);
}
}