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A simple tool to read/write Mifare RFID tags with an ACR122U device
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Here is a simple Java program to read/write Mifare RFID tags with an ACR122U device.


  • Read/dump Mifare Classic tags
  • Write to Mifare Classic tags (block-wise)
  • ACR122U compliant
  • Supported tags: Mifare Classic 1K (only)
  • JRE 7.0 or later
  • MIT Licensed


~$ mvn clean package


~$ java -jar ./acr122urw.jar -h
Usage: java -jar acr122urw.jar [option]
    -h, --help                      show this help message and exit
    -d, --dump [KEYS...]            dump Mifare Classic 1K cards using KEYS
    -w, --write S B KEY DATA        write DATA to sector S, block B of Mifare Classic 1K cards using KEY
    java -jar acr122urw.jar --dump FF00A1A0B000 FF00A1A0B001 FF00A1A0B099
    java -jar acr122urw.jar --write 13 2 FF00A1A0B001 FFFFFFFFFFFF00000000060504030201

About the ACR122U reader/writer

ACR122U NFC reader/writer

The ACR122U NFC Reader is made by Advanced Card Systems Ltd (Hong Kong, China).

Device features

  • PC-linked contactless smart card (NFC) reader/writer
  • Contactless operating frequency: 13.56 MHz
  • Supports: ISO14443 Type A & B, MIFARE®, FeliCa, 4 types of NFC (ISO/IEC18092) tags
  • Interface: USB
  • Operating Distance: Up to 50 mm (depends on the tag type)
  • Operating Voltage: DC 5.0V
  • Operating Frequency: 13.56 MHz
  • Compliance/Certifications: ISO 14443, PC/SC, CCID
  • Size: 98 mm x 65 mm x 12.8 mm
  • Weight: 70 g


System requirements

~# # For Debian Testing
~# echo "install pn533 /bin/false" >> /etc/modprobe.d/blacklist-nfc.conf
~# echo "install nfc /bin/false" >> /etc/modprobe.d/blacklist-nfc.conf
~# modprobe -r pn533 nfc
~# apt-get install libpcsclite1 libccid pcscd libacsccid1 pcsc-tools
~# pcscd -f


Bitcoin address: 13BMqpqbzJ62LjMWcPGWrTrdocvGqifdJ3

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