Adafruit ST25DV16K I2C RFID EEPROM Breakout - STEMMA QT / Qwiic

ST25DV16K dual-interface RFID/NFC tag breakout: readable by phones as an ISO/IEC 15693 (13.56 MHz) tag, and rewritable over I2C from a microcontroller. STEMMA QT / Qwiic connector; 16 Kbit EEPROM.

Logical pinout · physical placement not verified

Vin
Board power input. Adafruit Learn states the chip can safely run from 3-5VDC and should be powered at the same voltage as the host logic level.
Type · PowerVoltage · 3V to 5V DC
GND
Common ground for power and logic.
Type · GroundVoltage · 0V
SCL
I2C clock pin. Connect to the microcontroller I2C clock line; the board has a 10K pullup on this pin.
Type · I2C
SDA
I2C data pin. Connect to the microcontroller I2C data line; the board has a 10K pullup on this pin.
Type · I2C
STEMMA QT
STEMMA QT / Qwiic connector path for I2C connection to compatible development boards or accessories.
Type · Unknown
GPO
General purpose output configurable to provide RF activity information. Adafruit notes it needs an external pullup resistor above 4.7 kΩ.
Type · Signal
VEH
Analog energy-harvesting voltage output available when energy harvesting is enabled and RF field strength is sufficient. Adafruit notes this voltage is not regulated.
Type · PowerVoltage · unregulated energy-harvesting output

Pin	Type	Function	Voltage
Vin	Power	Board power input. Adafruit Learn states the chip can safely run from 3-5VDC and should be powered at the same voltage as the host logic level.	3V to 5V DC
GND	Ground	Common ground for power and logic.	0V
SCL	I2C	I2C clock pin. Connect to the microcontroller I2C clock line; the board has a 10K pullup on this pin.
SDA	I2C	I2C data pin. Connect to the microcontroller I2C data line; the board has a 10K pullup on this pin.
STEMMA QT	Unknown	STEMMA QT / Qwiic connector path for I2C connection to compatible development boards or accessories.
GPO	Signal	General purpose output configurable to provide RF activity information. Adafruit notes it needs an external pullup resistor above 4.7 kΩ.
VEH	Power	Analog energy-harvesting voltage output available when energy harvesting is enabled and RF field strength is sufficient. Adafruit notes this voltage is not regulated.	unregulated energy-harvesting output

Logical pinout · physical placement not verified

Pin details

7 connections

Vin
Board power input. Adafruit Learn states the chip can safely run from 3-5VDC and should be powered at the same voltage as the host logic level.
PowerVoltage · 3V to 5V DC
GND
Common ground for power and logic.
GroundVoltage · 0V
SCL
I2C clock pin. Connect to the microcontroller I2C clock line; the board has a 10K pullup on this pin.
I2C
SDA
I2C data pin. Connect to the microcontroller I2C data line; the board has a 10K pullup on this pin.
I2C
STEMMA QT
STEMMA QT / Qwiic connector path for I2C connection to compatible development boards or accessories.
Unknown
GPO
General purpose output configurable to provide RF activity information. Adafruit notes it needs an external pullup resistor above 4.7 kΩ.
Signal
VEH
Analog energy-harvesting voltage output available when energy harvesting is enabled and RF field strength is sufficient. Adafruit notes this voltage is not regulated.
PowerVoltage · unregulated energy-harvesting output

Start wiring

I2C · UART · SPI · 3.3 – 5 V · Breakout

Confirm the data interface matches your host board.

Module pins: Vin, VEH, GND, SCL, SDA, GPO. Schematik maps them to your board in the app.

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