SparkFun Qwiic Dynamic NFC RFID Tag ST25DV64KC 64K EEPROM GPO Pin

Description

Product Overview

The SparkFun Qwiic Dynamic NFC RFID Tag ST25DV64KC is a highly integrated, low‑power tag designed for developers who need a flexible, data‑rich NFC/RFID solution. Housed in a tiny 1.1 × 1.1 × 0.24 inch package, the tag includes a 64 KB EEPROM memory array that can be accessed via I²C or over the air using standard NFC‑compatible smartphones and readers. A dedicated General‑Purpose Output (GPO) pin provides a hardware interrupt that can be configured to indicate events such as RF field presence, data write completion, or mailbox activity. The tag also features an energy‑harvesting pin capable of delivering microwatts of power when exposed to a sufficiently strong RF field, enabling battery‑free or ultra‑low‑power designs. Operating from 1.8 V to 5.5 V, the device is fully compatible with SparkFun’s Qwiic ecosystem, allowing quick plug‑and‑play connections without soldering.

Usage

This tag is suited for a wide range of applications where compact size, secure data storage, and wireless accessibility are essential. Typical use cases include smart‑home sensors that report temperature or humidity data to a mobile app, access‑control badges that store encrypted credentials, inventory tags that log product movement, and educational kits that teach students about NFC communication and I²C interfacing. Because the tag can be powered solely by the RF field, it is perfect for remote or hard‑to‑reach locations where battery replacement would be impractical. The Qwiic connector simplifies integration with development boards such as the Arduino Nano 33 IoT, Raspberry Pi Pico, or any other Qwiic‑compatible platform, making it an excellent choice for rapid prototyping and proof‑of‑concept projects.

Why Choose Us

Choosing the SparkFun Qwiic Dynamic NFC RFID Tag means selecting a product backed by SparkFun’s reputation for quality, reliability, and community support. Each tag undergoes rigorous testing to ensure consistent performance across temperature ranges and RF environments. The ST25DV64KC IC is sourced directly from STMicroelectronics, guaranteeing long‑term availability and adherence to industry standards. SparkFun provides comprehensive documentation, example code, and a vibrant forum where developers can share ideas and troubleshoot issues. Additionally, the tag’s robust design includes protection against accidental overwrites, with optional password protection for each memory sector, ensuring that sensitive data remains secure.

Key Features

• 64 KB EEPROM lets you store substantial configuration data, logs, or user credentials directly on the tag.
• GPO pin provides real‑time hardware interrupts for immediate response to RF field changes or mailbox events.
• Energy‑harvesting capability powers the tag from a nearby RF source, eliminating the need for batteries in many applications.
• Wide operating voltage range (1.8 V‑5.5 V) ensures compatibility with most microcontroller platforms.
• SparkFun’s dedicated support team and extensive online resources help you get up and running quickly.

FAQ

What is the difference between the Mailbox and EEPROM memory?

The Mailbox is a 256‑byte buffer that can be quickly transferred between the tag and an I²C master, enabling fast data exchange during a single RF session. EEPROM is non‑volatile storage that retains data even when power is removed, suitable for long‑term configuration or logging.

Can I protect the stored data with a password?

Yes, the ST25DV64KC supports sector‑level password protection. You can set read and write passwords for each memory block, preventing unauthorized access while still allowing trusted devices to update the data.

How much power can the energy‑harvesting pin supply?

The pin can deliver a few microwatts when the tag is exposed to a strong RF field, enough to power low‑energy sensors or to keep the tag’s internal circuitry active without an external battery.

Is the tag compatible with standard NFC smartphones?

Absolutely. Any NFC‑enabled smartphone can read the tag’s EEPROM contents and write data when the tag is within the phone’s RF field, making it ideal for user‑friendly configuration and data retrieval.

What development tools do you recommend for getting started?

We recommend using SparkFun’s Qwiic libraries for Arduino or CircuitPython, which include ready‑made functions for reading and writing EEPROM, handling the GPO interrupt, and managing the Mailbox. Sample sketches and detailed wiring diagrams are available on our product page.