/** * ---------------------------------------------------------------------------- * This is a MFRC522 library example; see https://github.com/miguelbalboa/rfid * for further details and other examples. * * NOTE: The library file MFRC522.h has a lot of useful info. Please read it. * * Released into the public domain. * ---------------------------------------------------------------------------- * This sample shows how to read and write data blocks on a MIFARE Classic PICC * (= card/tag). * * BEWARE: Data will be written to the PICC, in sector #1 (blocks #4 to #7). * * * Typical pin layout used: * ----------------------------------------------------------------------------------------- * MFRC522 Arduino Arduino Arduino Arduino Arduino * Reader/PCD Uno/101 Mega Nano v3 Leonardo/Micro Pro Micro * Signal Pin Pin Pin Pin Pin Pin * ----------------------------------------------------------------------------------------- * RST/Reset RST 9 5 D9 RESET/ICSP-5 RST * SPI SS SDA(SS) 10 53 D10 10 10 * SPI MOSI MOSI 11 / ICSP-4 51 D11 ICSP-4 16 * SPI MISO MISO 12 / ICSP-1 50 D12 ICSP-1 14 * SPI SCK SCK 13 / ICSP-3 52 D13 ICSP-3 15 * */ #include#include constexpr uint8_t RST_PIN = 9; // Configurable, see typical pin layout above constexpr uint8_t 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 for (byte i = 0; i < 6; i++) { key.keyByte[i] = 0xFF; } 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 = 1; byte blockAddr = 4; byte dataBlock[] = { 0x01, 0x02, 0x03, 0x04, // 1, 2, 3, 4, 0x05, 0x06, 0x07, 0x08, // 5, 6, 7, 8, 0x09, 0x0a, 0xff, 0x0b, // 9, 10, 255, 11, 0x0c, 0x0d, 0x0e, 0x0f // 12, 13, 14, 15 }; byte trailerBlock = 7; 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); } }