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ArduinoでRFIDモジュール（MFRC522）を使ってタグに名前の書き込み・読み込みをする

公開: 2022-01-25 / 更新: 2025-07-16

Arduinoブログ電子工作 #arduino

今回使うもの

Arduino Uno Rev3 ATmega328 マイコンボード A000066 白

VKLSVAN 3個セット RFIDモジュール FRC RC522 MFRC522 IC カード リーダー モジュール+ S50 非接触ICタグ + カードキー Mifare

使用する前のセッティング

以下の記事を参考にしてください。

非接触ICタグで遊ぼう！ArduinoでRFIDリーダRC522を使う方法

とりあえず私はこんなかんじ。無駄にマイクロビット繋げてますけど気にしないでください。

コード

ライブラリのサンプルをそのまま使います。

https://github.com/miguelbalboa/rfid/tree/master/examples

まずは書き込みから。

/*
 * Write personal data of a MIFARE RFID card using a RFID-RC522 reader
 * Uses MFRC522 - Library to use ARDUINO RFID MODULE KIT 13.56 MHZ WITH TAGS SPI W AND R BY COOQROBOT. 
 * -----------------------------------------------------------------------------------------
 *             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
 *
 * More pin layouts for other boards can be found here: https://github.com/miguelbalboa/rfid#pin-layout
 *
 * Hardware required:
 * Arduino
 * PCD (Proximity Coupling Device): NXP MFRC522 Contactless Reader IC
 * PICC (Proximity Integrated Circuit Card): A card or tag using the ISO 14443A interface, eg Mifare or NTAG203.
 * The reader can be found on eBay for around 5 dollars. Search for "mf-rc522" on ebay.com. 
 */

#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


void setup() {
Serial.begin(9600);        // Initialize serial communications with the PC
SPI.begin();               // Init SPI bus
mfrc522.PCD_Init();        // Init MFRC522 card
Serial.println(F(“Write personal data on a MIFARE PICC ”));
}


void loop() {


// Prepare key - all keys are set to FFFFFFFFFFFFh at chip delivery from the factory.
MFRC522::MIFARE_Key key;
for (byte i = 0; i < 6; i++) key.keyByte[i] = 0xFF;


// Reset the loop if no new card present on the sensor/reader. This saves the entire process when idle.
if ( ! mfrc522.PICC_IsNewCardPresent()) {
return;
}


// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial()) {
return;
}


Serial.print(F(“Card UID:”));    //Dump UID
for (byte i = 0; i < mfrc522.uid.size; i++) {
Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? ” 0” : ” ”);
Serial.print(mfrc522.uid.uidByte[i], HEX);
}
Serial.print(F(” PICC type: ”));   // Dump PICC type
MFRC522::PICC_Type piccType = mfrc522.PICC_GetType(mfrc522.uid.sak);
Serial.println(mfrc522.PICC_GetTypeName(piccType));


byte buffer[34];
byte block;
MFRC522::StatusCode status;
byte len;


Serial.setTimeout(20000L) ;     // wait until 20 seconds for input from serial
// Ask personal data: Family name
Serial.println(F(“Type Family name, ending with #”));
len = Serial.readBytesUntil(’#’, (char *) buffer, 30) ; // read family name from serial
for (byte i = len; i < 30; i++) buffer[i] = ’ ’;     // pad with spaces


block = 1;
//Serial.println(F(“Authenticating using key A…”));
status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, block, &key, &(mfrc522.uid));
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“PCD_Authenticate() failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
else Serial.println(F(“PCD_Authenticate() success: ”));


// Write block
status = mfrc522.MIFARE_Write(block, buffer, 16);
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“MIFARE_Write() failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
else Serial.println(F(“MIFARE_Write() success: ”));


block = 2;
//Serial.println(F(“Authenticating using key A…”));
status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, block, &key, &(mfrc522.uid));
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“PCD_Authenticate() failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}


// Write block
status = mfrc522.MIFARE_Write(block, &buffer[16], 16);
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“MIFARE_Write() failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
else Serial.println(F(“MIFARE_Write() success: ”));


// Ask personal data: First name
Serial.println(F(“Type First name, ending with #”));
len = Serial.readBytesUntil(’#’, (char *) buffer, 20) ; // read first name from serial
for (byte i = len; i < 20; i++) buffer[i] = ’ ’;     // pad with spaces


block = 4;
//Serial.println(F(“Authenticating using key A…”));
status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, block, &key, &(mfrc522.uid));
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“PCD_Authenticate() failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}


// Write block
status = mfrc522.MIFARE_Write(block, buffer, 16);
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“MIFARE_Write() failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
else Serial.println(F(“MIFARE_Write() success: ”));


block = 5;
//Serial.println(F(“Authenticating using key A…”));
status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, block, &key, &(mfrc522.uid));
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“PCD_Authenticate() failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}


// Write block
status = mfrc522.MIFARE_Write(block, &buffer[16], 16);
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“MIFARE_Write() failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
else Serial.println(F(“MIFARE_Write() success: ”));


Serial.println(” ”);
mfrc522.PICC_HaltA(); // Halt PICC
mfrc522.PCD_StopCrypto1();  // Stop encryption on PCD


}

すると以下のような出力がシリアルモニターに表示されます。

Type Family name, ending with #

そしたら入力欄にファーストネーム「hoge#」を打ち込みましょう。入力の最後は#で終わらせる必要があります。すると以下の出力が続きます。

PCD_Authenticate() success: MIFARE_Write() success: MIFARE_Write() success: Type First name, ending with #

最後に「taro#」と打ち込めば完了です。

次に読み込み。

/*
 * Initial Author: ryand1011 (https://github.com/ryand1011)
 *
 * Reads data written by a program such as "rfid_write_personal_data.ino"
 *
 * See: https://github.com/miguelbalboa/rfid/tree/master/examples/rfid_write_personal_data
 *
 * Uses MIFARE RFID card using RFID-RC522 reader
 * Uses MFRC522 - Library
 * -----------------------------------------------------------------------------------------
 *             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
 *
 * More pin layouts for other boards can be found here: https://github.com/miguelbalboa/rfid#pin-layout
*/

#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


//*****************************************************************************************//
void setup() {
Serial.begin(9600);                                           // Initialize serial communications with the PC
SPI.begin();                                                  // Init SPI bus
mfrc522.PCD_Init();                                              // Init MFRC522 card
Serial.println(F(“Read personal data on a MIFARE PICC:”));    //shows in serial that it is ready to read
}


//*****************************************************************************************//
void loop() {


// Prepare key - all keys are set to FFFFFFFFFFFFh at chip delivery from the factory.
MFRC522::MIFARE_Key key;
for (byte i = 0; i < 6; i++) key.keyByte[i] = 0xFF;


//some variables we need
byte block;
byte len;
MFRC522::StatusCode status;


//-------------------------------------------


// Reset the loop if no new card present on the sensor/reader. This saves the entire process when idle.
if ( ! mfrc522.PICC_IsNewCardPresent()) {
return;
}


// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial()) {
return;
}


Serial.println(F(“Card Detected:”));


//-------------------------------------------


mfrc522.PICC_DumpDetailsToSerial(&(mfrc522.uid)); //dump some details about the card


//mfrc522.PICC_DumpToSerial(&(mfrc522.uid));      //uncomment this to see all blocks in hex


//-------------------------------------------


Serial.print(F(“Name: ”));


byte buffer1[18];


block = 4;
len = 18;


//------------------------------------------- GET FIRST NAME
status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, 4, &key, &(mfrc522.uid)); //line 834 of MFRC522.cpp file
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“Authentication failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}


status = mfrc522.MIFARE_Read(block, buffer1, &len);
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“Reading failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}


//PRINT FIRST NAME
for (uint8_t i = 0; i < 16; i++)
{
if (buffer1[i] != 32)
{
Serial.write(buffer1[i]);
}
}
Serial.print(” ”);


//---------------------------------------- GET LAST NAME


byte buffer2[18];
block = 1;


status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, 1, &key, &(mfrc522.uid)); //line 834
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“Authentication failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}


status = mfrc522.MIFARE_Read(block, buffer2, &len);
if (status != MFRC522::STATUS_OK) {
Serial.print(F(“Reading failed: ”));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}


//PRINT LAST NAME
for (uint8_t i = 0; i < 16; i++) {
Serial.write(buffer2[i] );
}


//----------------------------------------


Serial.println(F(“\nEnd Reading\n”));


delay(1000); //change value if you want to read cards faster


mfrc522.PICC_HaltA();
mfrc522.PCD_StopCrypto1();
}
//*****************************************************************************************//

すると以下が出力されます。

Card Detected: Card UID: xxxx Card SAK: xxxx PICC type: MIFARE 1KB Name: taro hoge
End Reading

注意点

一点はまったポイントがあるので記しておきます。書き込み時に以下のような出力が出る場合があります。

PCD_Authenticatie Failed…

MFRC522では各種操作の前に以下リンク先の205行目にあるPICC_CMD_MF_AUTH_KEY_Aを用いてタグの認証を行います。

https://github.com/miguelbalboa/rfid/blob/master/src/MFRC522.h

上記エラーはこの認証が通らなかったことを意味するのですが、事前の鍵情報の書き込みをしてない限りそれはあり得ません。

ではなぜ起こったのか？それは「書き込みが完了する前にタグをリーダから離してしまった」からです。書き込みが完了するまでは以下のようにしっかりとタグを読み込ませておかないと認証が失敗してしまうので気を付けてください。