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本帖最后由 maxims 于 2016-4-28 17:22 编辑
- /**
- * Helper routine to dump a byte array as hex values to Serial.
- */
- void printHex(byte *buffer, byte bufferSize) {
- for (byte i = 0; i < bufferSize; i++) {
- Serial.print(buffer[i] < 0x10 ? " 0" : " ");
- Serial.print(buffer[i], HEX);
- }
- }
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Rc522的卡号,读出来是数组格式,一般用上面的方法进行输出为字符串。
但是,我在程序中需要引用它。通常是如下引用 - if (rfid.uid.uidByte[0] != nuidPICC[0] ||
- rfid.uid.uidByte[1] != nuidPICC[1] ||
- rfid.uid.uidByte[2] != nuidPICC[2] ||
- rfid.uid.uidByte[3] != nuidPICC[3] ) {
- Serial.println(F("A new card has been detected."));
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但是,我只想要16进制的字符串引用,该如何转换呢?
比如,我需要直接输出到1602,它就必须是"xxxxxxxx"这种【16进制字符串】
这是RC522的Demo - #include <SPI.h>
- #include <MFRC522.h>
- #define SS_PIN 10
- #define RST_PIN 9
-
- MFRC522 rfid(SS_PIN, RST_PIN); // Instance of the class
- MFRC522::MIFARE_Key key;
- // Init array that will store new NUID
- byte nuidPICC[3];
- void setup() {
- Serial.begin(9600);
- SPI.begin(); // Init SPI bus
- rfid.PCD_Init(); // Init MFRC522
- for (byte i = 0; i < 6; i++) {
- key.keyByte[i] = 0xFF;
- }
- Serial.println(F("This code scan the MIFARE Classsic NUID."));
- Serial.print(F("Using the following key:"));
- printHex(key.keyByte, MFRC522::MF_KEY_SIZE);
- }
-
- void loop() {
- // Look for new cards
- if ( ! rfid.PICC_IsNewCardPresent())
- return;
- // Verify if the NUID has been readed
- if ( ! rfid.PICC_ReadCardSerial())
- return;
- Serial.print(F("PICC type: "));
- MFRC522::PICC_Type piccType = rfid.PICC_GetType(rfid.uid.sak);
- Serial.println(rfid.PICC_GetTypeName(piccType));
- // Check is the PICC of Classic MIFARE type
- if (piccType != MFRC522::PICC_TYPE_MIFARE_MINI &&
- piccType != MFRC522::PICC_TYPE_MIFARE_1K &&
- piccType != MFRC522::PICC_TYPE_MIFARE_4K) {
- Serial.println(F("Your tag is not of type MIFARE Classic."));
- return;
- }
- if (rfid.uid.uidByte[0] != nuidPICC[0] ||
- rfid.uid.uidByte[1] != nuidPICC[1] ||
- rfid.uid.uidByte[2] != nuidPICC[2] ||
- rfid.uid.uidByte[3] != nuidPICC[3] ) {
- Serial.println(F("A new card has been detected."));
- // Store NUID into nuidPICC array
- for (byte i = 0; i < 4; i++) {
- nuidPICC[i] = rfid.uid.uidByte[i];
- }
-
- Serial.println(F("The NUID tag is:"));
- Serial.print(F("In hex: "));
- printHex(rfid.uid.uidByte, rfid.uid.size);
- Serial.println();
- Serial.print(F("In dec: "));
- printDec(rfid.uid.uidByte, rfid.uid.size);
- Serial.println();
- }
- else Serial.println(F("Card read previously."));
- // Halt PICC
- rfid.PICC_HaltA();
- // Stop encryption on PCD
- rfid.PCD_StopCrypto1();
- }
- /**
- * Helper routine to dump a byte array as hex values to Serial.
- */
- void printHex(byte *buffer, byte bufferSize) {
- for (byte i = 0; i < bufferSize; i++) {
- Serial.print(buffer[i] < 0x10 ? " 0" : " ");
- Serial.print(buffer[i], HEX);
- }
- }
- /**
- * Helper routine to dump a byte array as dec values to Serial.
- */
- void printDec(byte *buffer, byte bufferSize) {
- for (byte i = 0; i < bufferSize; i++) {
- Serial.print(buffer[i] < 0x10 ? " 0" : " ");
- Serial.print(buffer[i], DEC);
- }
- }
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