RFID & NFC

13.56 MHz NFC readers, long-range UHF readers, passive MiFare tags, and the rewritable ST25DV dynamic tag each play a different role in the link. Matching them correctly matters.

PN532 and WS1850S 13.56 MHz readers, ID01 UHF RFID modules (UART/RS485/USB), MiFare Classic 1K cards and fobs, and the I2C-rewritable ST25DV16K dynamic tag.

• PN532 boards (the Pimoroni breakout and DFRobot's Gravity UART/I2C NFC module) and the WS1850S-based M5Stack RFID 2 Unit read 13.56 MHz MiFare Classic 1K cards, fobs, and bracelets at a few centimeters.
• The ST25DV16K STEMMA QT/Qwiic breakout is a dynamic tag: phone-readable ISO 15693 on the RF side, rewritable EEPROM over I2C on the MCU side — for handing data to phones, not reading cards.
• DFRobot's ID01 UHF RFID modules (UART, RS485, and USB variants) work the UHF band for long-range reads — a different frequency and tag family from anything at 13.56 MHz.
• The ST25R3911B development and evaluation kits pair the reader IC with an STM32F103RCT6 controller for multi-protocol NFC reader work beyond a fixed-function breakout.