The SparkFun Qwiic Dynamic NFC/RFID Tag features the ST25DV64KC dynamic Near Frequency Communication (NFC) / Radio Frequency Identification (RFID) tag IC from STMicroelectronics©. The ST25DV64KC offers 64-kBit (8-kBytes) of EEPROM memory which can be accessed over both I²C and RF (NFC)! It's a state-of-the-art tag that conforms to ISO/IEC 15693 or NFC Forum Type 5 recommendations. You can even read and write the tag's memory using NFC even while the tag is powered down or disconnected!

The SparkFun Qwiic Dynamic NFC/RFID Tag includes 64 Kbit EEPROM for users to write and read data from, a general purpose output to act as an external interrupt reporting events such as RF field changes, RF activity, I²C writes and RF switches toggling over I²C. The IC has a supply voltage range of 1.8V to 5.5V though when in a Qwiic circuit it runs at 3.3V. It also includes an energy harvesting pin capable of outputting µW of power with an RF field of sufficient strength.

The ST25DV64KC supports a fast transfer mode to send the contents of a 256-byte buffer between a device connected to the tag over I²C (referred to as the tag's Mailbox) and an RF device such as a reader or smartphone. This makes it so you can store data on the tag and have it available for reading by an RF device by simply bringing it into the RF read range, even if the tag is powered off. This data can also be password protected with a 64-bit value.

Our Arduino Library provides all of the methods you need to read and write the user memory, control the read and write permissions, alter the area sizes, and apply password control. We've also included extra methods which will let you read and write NDEF (NFC Forum Data Exchange Format) URI, WiFi, and Text records that your smartphone can understand! We've tested it with ST's "NFC Tap" App - available from the Apple App Store and Google Play. For Android users, we can also recommend wakdev's NFC Tools.

The SparkFun Qwiic Connect System is an ecosystem of I²C sensors, actuators, shields and cables that make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector. This reduces the amount of required PCB space, and polarized connections mean you can’t hook it up wrong.

ST25DV64KC Features:

• Contactless Interface
  • Based on ISO/IEC 15693
  • NFC Forum Type 5 tag certified by the NFC Forum
  • Supports all ISO/IEC 15693 modulations, coding, sub-carrier modes and data rates
  • Custom fast read access up to 53kbit/s
• Memory
  • 64-kBit (8-kByte) of EEPROM
  • I²C interface accesses bytes
  • RF interface accesses blocks of 4 bytes
  • Write time:
  • From I²C: typical 5ms for 1 up to 16 bytes
  • From RF: typical 5ms for 1 block
  • Data retention: 40 years
  • Write cycle endurance: 400k to 1 million depending on temperature
• Data protection
  • User memory: one to four configurable areas, protectable in read and/or write by three 64-bit passwords in RF and one 64‑bit password in I²C
  • System configuration: protected in write by a 64-bit password in RF and a 64-bit password in I²C
• General Purpose Output (GPO) pin
  • Interrupt pin configurable on multiple RF and I²C events
• Energy Harvesting
• Supply Voltage: 1.8V_Min, 5.5V_Max
  • Note: Qwiic bus operates at 3.3V_Max
• I²C Addresses:
  • User Memory: 0x53
  • System Memory: 0x57
  • RF Switch Off: 0x51
  • RF Switch On: 0x55

Arduino Library Features:

• Read and write EEPROM memory via I²C
• Change the size of the four user memory areas
• Apply different levels of protection to the four areas
• Change the I²C password
• Read and Write NDEF (NFC Forum Data Exchange Format) records:
  • URI
  • WiFi
  • Text

• Schematic
• Eagle Files
• Board Dimensions
• Hookup Guide
• Datasheet (ST25DV64KC)
• "NFC Tap" App
  • iOS
  • Google Play
• wakdev's NFC Tools
• Qwiic Information Page
• Arduino Library
• Library Documentation
• GitHub Hardware Repo