• RFID
  • Beginner
  • 5 min
  • Serial CLI

Recipe · Beginner · RFID

How to read a PN532 RFID tag UID

With a PN532 module in I2C mode, Bit Pirate can poll for a tag and print its UID and type information. This recipe intentionally stays read-only.

RFID reader communicating with a contactless tag.
Read UID and tag metadata first; do not jump to write/clone actions.

Wiring View

PN532 BP SDAI2C SDASCLI2C SCLVCC3.3V/5V as modu...GNDBP GND
Generated from the wiring summary: PN532 to BP.
Step 1

Commands

Run the commands below after selecting the right Bit Pirate mode and confirming the wiring.

Result

What success looks like

The UID and tag family appear repeatedly while the tag is near the antenna. If nothing appears, check PN532 mode switches and wiring.

Troubleshooting

  • PN532 board is not in I2C mode.
  • SDA/SCL swapped.
  • Tag is too far from the antenna.
  • Using a tag family not supported by the current read path.

Next steps

  • Use the UID/type to choose the correct documentation.
  • Use write/clone flows only on your own lab cards.
  • Keep a photo or note of the UID for the project log.

PN532 RFID read FAQ

What should a successful read show?

A stable PN532 read should repeatedly show the tag UID, ATQA, SAK and interpreted tag type while the tag remains near the antenna.

What does a successful PN532 read usually provide?

A successful read usually gives the tag type, UID and enough metadata to decide whether the next step is simple identification, NTAG page access or a MIFARE-specific workflow.

Does UID read mean the tag content is accessible?

No. UID polling only identifies the tag. Reading or writing memory can still require the correct tag family, keys, authentication state or unlocked NTAG pages.

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