MFRC522: Firmware Unknown

Question

Can someone help me what is the meaning of this sketch? It always outputs in the serial monitor:

Firmware Version: 0x1C = (unknown)
Scan PICC to see UID, SAK, type, and data blocks...

This is the code of the MFRC522 library I use:

#include <SPI.h>
#include <MFRC522.h>
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
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
 mfrc522.PCD_DumpVersionToSerial(); // Show details of PCD - MFRC522 Card Reader details
 Serial.println(F("Scan PICC to see UID, SAK, type, and data blocks..."));
}
void loop() {
 // Look for new cards
 if ( ! mfrc522.PICC_IsNewCardPresent()) {
 return;
 }
 // Select one of the cards
 if ( ! mfrc522.PICC_ReadCardSerial()) {
 return;
 }
 // Dump debug info about the card; PICC_HaltA() is automatically called
 mfrc522.PICC_DumpToSerial(&(mfrc522.uid));
}

• Greenonline: The code is quite well commented, what don't you understand? The outputFirmware Version: line is obviously output by PCD_DumpVersionToSerial(). Do you get any other output other than that? You should also see Scan PICC to see.... Are you not seeing that? Please be more explicit, and include a few more lines of output, to illustrate any repetition of output.
• hotchongas: yes it also output but reader does not read the rfid card nor the rfid key , that is why I assumed that was the error
• Greenonline: Try running the firmware_check example. In that sketch, it does say that only known versions are supported (Serial.println(F("Only known versions supported"));), so your first output line doesn't bode well
• Greenonline: Please add a link to your post, to the library that you are using. Is it this one: github.com/miguelbalboa/rfid?
• hotchongas: yes, thats the one I use.

Answer 1

The mention of unknown in the output line:

Firmware Version: 0x1C = (unknown)

isn't a good sign.

Run the firmware_check example to verify that first, before trying to run other code.

The unknown is output by line 1302 of MFRC522.cpp:

 default: Serial.println(F(" = (unknown)"));

The firmware_check example states on line 49:

 Serial.println(F("Only known versions supported"));

So, your hardware (i.e. the reader) may not be supported.

The only thing I can suggest is try another reader. Also, read the README, there maybe some thing there, or contact the author and/or raise an issue to see if you can get support for your version of the firmware (0x1C) added.

Answer 2

Put a delay(5) after

mfrc522.PCD_Init(); // Init MFRC522

and it will show the correct firmware version.