Adafruit RFID tag: ST25DV16K I2C EEPROM Breakout

A unique RFID/NFC breakout built around the ST25DV04 chip — it shows up as an ISO/IEC 15693 (13.56MHz) tag readable by phones and tablets, but unlike standard passive tags it can be reprogrammed over I2C from a microcontroller. This makes it ideal for dynamic applications where you want to update the tag's content in real time.

For example: a microcontroller can write different URLs a few seconds apart, and a phone will detect each one in sequence. Includes a PCB trace antenna, STEMMA QT connector (SparkFun Qwiic compatible), and standard 2.54mm headers for breadboard use.

Important notes:

• Popular hobby RFID chips like the PN532 do not support ISO15693 — you cannot use those to read the ST25DV once programmed
• Requires a SAMD-based board (Metro M0 or better) — Arduino UNO (ATmega328p) does not have enough RAM
• No CircuitPython library available — Arduino only
• QT cable not included
• ST Arduino library for writing NFC URLs over I2C

I2C Interface

• 1MHz I2C protocol, addresses 0x2D, 0x53 (user memory), 0x57 (system memory)
• Supply voltage: 1.8V – 5.5V
• Multiple byte write up to 256 bytes

Contactless Interface

• ISO/IEC 15693, NFC Forum Type 5 certified
• Fast read up to 53 Kbit/s
• Internal tuning capacitance: 28.5pF

Memory

• 16Kbit EEPROM | Data retention: 40 years
• Write endurance: 1M cycles @ 25°C
• Energy harvesting: analog output pin to power external components

Dimensions: 31.7 × 25.3 × 4.6mm

Related products

• Need a standard RC522 reader? See the RFID RC522 Board and Tags.
• Want flat card-style tags? Try the Black 13.56MHz RFID Tag.
• Need a SAMD board to drive it? See the Adafruit Gemma M0 or QT Py SAMD21.