RFID-MFRC522 with M5Stack

RFID-MFRC522-with-M5Stack.ino

#include <SPI.h>
#include <MFRC522.h>
#include <M5Stack.h>

constexpr uint8_t RST_PIN = 2;
constexpr uint8_t SS_PIN = 5;


MFRC522 mfrc522(SS_PIN, RST_PIN);  // Create MFRC522 instance
MFRC522::MIFARE_Key key;

void setup() {
    M5.begin(true, false, true, false); //SD, I2Cをdisableに
    
    while (!Serial);    // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
    mfrc522.PCD_Init();   // Init MFRC522
    mfrc522.PCD_DumpVersionToSerial();  // Show details of PCD - MFRC522 Card Reader details
    dump_byte_array(key.keyByte, MFRC522::MF_KEY_SIZE);

    M5.Lcd.begin(); // 画面のbeginを再実行する
    M5.Lcd.fillScreen(BLACK);
    M5.Lcd.setCursor(0, 0);
    M5.Lcd.setTextSize(2);
    M5.Lcd.println("Scan PICC to see UID, SAK, type, and data blocks...");
    Serial.println("Scan PICC to see UID, SAK, type, and data blocks...");
}

void loop() {
  
  //カードの読み取り確認
  if (!mfrc522.PICC_IsNewCardPresent() || ! mfrc522.PICC_ReadCardSerial()) {
    // (!mfrc522.PICC_IsNewCardPresent()) : Look for new cards
    // (!mfrc522.PICC_ReadCardSerial())   : Select one of the cards
    delay(500);
    return;
  }
  
  char mes1[9];
  sprintf(mes1, "%02x%02x%02x%02x", mfrc522.uid.uidByte[0], mfrc522.uid.uidByte[1], mfrc522.uid.uidByte[2], mfrc522.uid.uidByte[3]);
  Serial.printf("UID: %s\n", mes1);
  M5.Lcd.setCursor(10, 40);
  M5.Lcd.setTextSize(2);
  M5.Lcd.printf("UID: %s\n", mes1);
  
//  // Dump debug info about the card; PICC_HaltA() is automatically called
//  mfrc522.PICC_DumpToSerial(&(mfrc522.uid));
  delay(1000);
}


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);
    }
}