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

#define SS_PIN 10
#define RST_PIN 21
#define LED_PIN 48

MFRC522 mfrc522(SS_PIN, RST_PIN);

void setup() {
  Serial.begin(115200);
    // 明确指定 SPI 引脚: SCK=12, MISO=13, MOSI=11, SS=10
      SPI.begin(12, 13, 11, 10); 
        mfrc522.PCD_Init();
          pinMode(LED_PIN, OUTPUT);
            digitalWrite(LED_PIN, LOW);
              Serial.println("系统已启动，请刷卡...");
              }

              void loop() {
                // 检测新卡并读取序列号
                  if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()) {
                      Serial.print("检测到卡片，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.println();

                                                  // 亮灯并保持3秒
                                                      digitalWrite(LED_PIN, HIGH);
                                                          delay(3000);
                                                              digitalWrite(LED_PIN, LOW);

                                                                  // 终止与当前卡片的通信
                                                                      mfrc522.PICC_HaltA();
                                                                          mfrc522.PCD_StopCrypto1();
                                                                            }
                                                                              delay(100);
                                                                              }