Overview

The ST25DV16K is a dynamic NFC/RFID tag IC with dual I2C and RF interfaces, featuring 16Kbit of EEPROM memory. The Adafruit breakout (Product #4701) includes the STEMMA QT connector for easy I2C connection.

The module features:

• 16Kbit (2KB) EEPROM memory
• ISO/IEC 15693 and NFC Forum Type 5 compatible
• Dual interface: I2C and RF (13.56MHz)
• Fast Transfer Mode (FTM) support
• Energy harvesting output pin
• Mailbox for dynamic data exchange
• Password protection
• Operating voltage: 2.7V-5.5V
• I2C address: 0x57 (system memory at 0x2D)
• STEMMA QT / Qwiic compatible
• GPO interrupt pin

Configuration Notes

⚠️ Note: ESPHome does not have native support for ST25DV16K. You may need to use a custom component or access via raw I2C commands.

• Requires I2C interface
• I2C addresses: 0x57 (user memory), 0x2D (system config)
• Can be accessed via NFC reader or I2C interface simultaneously
• Energy harvesting allows powering small circuits from RF field
• Useful for contactless data exchange, configuration, or identification
• EEPROM provides non-volatile storage