RC522 RFID Mifare Reader Writer 13.56MHz Module Kit with S50 Card & Keychain for Arduino, ESP32, Raspberry Pi

Specifications:

• Operating Frequency: 13.56MHz
  
• Host Interface: SPI (Serial Peripheral Interface)
  
• Supported Protocols: ISO/IEC 14443A / MIFARE
  
• Supply Voltage: 2.5V to 3.3V (Standard 3.3V recommended)
  
• Sleep Current: < 80uA
  
• Read Range: 30mm - 50mm (Card dependent)
  
• Included Components: 1x RC522 Module, 1x S50 Card, 1x S50 Keychain Tag, 2x Header Pin Sets.

Project Evolution

• Past Projects (Prerequisites): If you've mastered the basic button-interfacing and I2C LCD displays, you're ready for RFID.
  
• Feature Upgrade: This RC522 kit unlocks Secure Identity Management and Non-Volatile Data Storage on external tokens.
  
• Effort Level: Intermediate. Requires SPI pin mapping and library installation.

Virtual Technician & Wiring

• ⚠️ Safety Warning: Never connect the VCC pin to 5V. The MFRC522 IC is rated for 3.3V only. Using a 5V supply will result in immediate hardware failure.

  RC522 Pin	Arduino Uno Pin	ESP32 Pin	Note
  VCC	3.3V	3V3	Power Source (3.3V ONLY)
  RST	D9	GPIO 22	Reset Pin
  GND	GND	GND	Ground
  MISO	D12	GPIO 19	SPI Master In
  MOSI	D11	GPIO 23	SPI Master Out
  SCK	D13	GPIO 18	SPI Clock
  SDA (SS)	D10	GPIO 5	Signal Selection

Package Includes:

1x RFID-RC522 Reader/Write Module

1x The standard mifare S50 blank card

1x S50 special-shaped keychain tag

1x Straight & right angle header strip

Frequently Asked Questions (Technical FAQs) 

1. How do I connect the RC522 to an Arduino Uno safely?
   Use the 3.3V pin for power and consider 1K resistors on the SPI lines for logic level protection.
   
2. What is the frequency of this RFID reader?
   It operates at high frequency (HF) 13.56MHz.
   
3. Can I read my phone's NFC with this?
   Yes, if your phone is in NFC emulation mode and uses ISO 14443A protocols.
   
4. Is the provided keychain tag rewritable?
   Yes, the S50 tags allow data to be written to specific sectors.
   
5. Why is my RC522 not detecting the card?
   Check your soldering on the headers and ensure the VCC is exactly 3.3V.
   
6. Can this read 125kHz tags?
   No, it is incompatible with 125kHz Low Frequency (LF) tags.
   
7. What is the default SPI speed?
   It supports up to 10Mbit/s.
   
8. Does it come with headers soldered?
   No, it includes straight and right-angle headers for DIY soldering.
   
9. How much data can a Mifare S50 card hold?
   It has 1KB of EEPROM divided into 16 sectors.
   
10. Can I use multiple RC522 modules on one Arduino?
    Yes, by using different SDA (SS) pins for each module.
    
11. Is the module waterproof?
    No, it must be used in a dry environment or a non-metallic enclosure.
    
12. Can it read through metal?
    No, metal will shield the RF signal and prevent reading.
    
13. What is the range of this RFID module?
    Typically between 3cm and 5cm.
    
14. Does it support I2C?
    The chip (MFRC522) supports it, but this specific PCB is wired for SPI.
    
15. What happens if I power it with 5V?
    The chip will likely burn out instantly as it is a 3.3V device.
    
16. How do I find the UID of my card?
    Use the "DumpInfo" example in the MFRC522 Arduino library.
    
17. Can I write a URL to the tag?
    Yes, you can write data in NDEF format for NFC compatibility.
    
18. Is this compatible with Raspberry Pi?
    Yes, it is very popular for Pi-based Python projects.
    
19. Why does it only work when the card is touching the antenna? Check for interference or insufficient power supply current.
    
20. Can it read through wood or plastic?
    Yes, it can read through most non-conductive materials easily.