ST25DV16K I2C RFID EEPROM

ST25DV16K I2C RFID EEPROM Breakout – STEMMA QT / Qwiic

This product consists of an RFID tag that works with mobile phones and can be reprogrammed via I2C.

This tag features an ISO/IEC 15693 (13.56 MHz) chip that can be read by both mobile phones and tablets. This feature is particularly useful, for example, whenever you want the tag to be dynamically rewritten when you connect it to a controller. Adafruit has tested it with a microcontroller: the microcontroller was instructed to write different URLs just a few seconds apart, and the mobile phone was able to detect the different URLs one after the other.

Once the tag has been programmed, it cannot be read using standard RFID read/write chips, such as the PN532, as these do not support ISO 15693. Tests carried out on both Apple and Android mobile phones showed that both were able to read this Adafruit tag without any problems.

The datasheet highlights that this product can be used as an ‘I2C to RFID’ transfer system for sending and receiving data from mobile devices, all wirelessly. In this case, however, it will be necessary to write a specific custom app.

There is a library written by ST that is very useful for writing NFC URLs to the chip via I2C. The Arduino UNO (ATmega328p) cannot be used with the ST25DV library, as it does not have enough RAM. To communicate with the ST25DV, you will need to use an MO or any other SAMD chip. At present, it can only be used with Arduino because there is not yet a Python or CircuitPython library available for this chip.

This breakout board contains an ST25DV04 chip, a support circuit and a PCB trace antenna, so establishing a connection is straightforward. If you wish to use this breakout board on a breadboard, you can use the standard 0.100”/2.54mm pitch headers included in the product packaging.

This breakout board also features Stemma QT connectors, which are compatible with SparkFun’s Qwiic.

If you’d rather not solder, this product allows you to avoid it. Thanks to these connectors, you simply need to plug in the sensor and you’ll be ready to start your project straight away.

Technical details of the ST25DV16K I2C RFID EEPROM Breakout:

• I2C interface
  – 1 MHz protocol supported by a two-wire I2C serial interface
  – Uses multiple I2C addresses: 0x2D, 0x53 (user memory) and 0x57 (system memory)
  – Single supply voltage: 1.8V to 5.5V
  – Multiple-byte write programming (up to 256 bytes)
• Contactless interface
  – Based on ISO/IEC 15693
  – NFC Forum Type 5 tag (certified by the NFC Forum)
  – Supports ISO/IEC 15693 modulations, coding, sub-carrier modes and data rates
  – Custom fast read access up to 53 Kbit/s
  – Single and multiple block reads (same for extended commands)
  – Single and multiple blocks write (up to 4) (same for Extended commands)
  – Internal tuning capacitance: 28.5 pF
• Memory
  – 16-kbits di EEPROM
  – I2C interface accesses bytes
  – RF interface accesses blocks of 4 bytes
  – Write time:
  From I2C: typical 5ms for 1 byte
  From RF: typical 5ms for 1 block
  – Data retention: 40 years
  – Write cycle endurance:
  1 million write cycles at 25 °C
  600k write cycles at 85 °C
  500k write cycles at 105 °C
  400k write cycles at 125 °C
• Fast transfer mode
  – Fast data transfer between I2C and RF interfaces
  – Half-duplex 256-byte dedicated buffer
• Energy harvesting
  – Analog output pin to power external components
• Data protection
  – User memory: 1 to 4 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.
• Product dimensions: 31.7 x 25.3 x 4.6 mm / 1.2″ x 1.0″ x 0.2″

Adafruit name: ST25DV16K I2C RFID EEPROM Breakout – STEMMA QT / Qwiic [ADA4701]