UM2235
Hardware description
and configuration
DocID030718 Rev 1
7/17
2
Hardware description and configuration
The X-NUCLEO-NFC04A1 expansion board allows the user to test the functionality of the
ST25DV04K NFC Type V/RFID tag IC with a dual-interface 4 kBit electrically erasable
programmable read-only memory (EEPROM) that also features an I²C interface.
The EEPROM is organized in blocks of 512 bytes, arranged by pages of 4 bytes in I²C
mode, and in 128 blocks of 4 bytes in RF mode. It can be powered by STM32 Nucleo
board or directly by the received carrier electromagnetic field.
The ST25DV04K features a low power down (LPD) pin, a general purpose output (GPO)
and an energy harvesting feature that lets you output the energy coming from the RF field
on the V
out
analog pin and acts on ST1 jumper to enable it.
The ST25DV04K can act as a mailbox in fast transfer mode in both directions between the
RF terminal (such as an e-reader or a smart phone) and the microcontroller through the
I²C. In this case, messages are stored in the RAM instead of EEPROM. This mode allows
exchanging up to 256 byte payload data via RF and I²C interfaces.
A user configurable output pin can also be used as an interrupt for the microcontroller, and
toggles during field change
a
(e.g., RF Busy, MailBox filled, EEPROM update, RF user
Interrupt and RF User Set/Reset).
ST25DV04K device standby current consumption can be further lowered using the
Low
Power Down
input pin that switches the ST25DV04K internal LDO off
b
.
These functions can be exploited using the firmware package contained in the X-CUBE-
NFC4 software
c
.
The STM32 Nucleo and the X-NUCLEO-NFC04A1 boards are connected through
connectors CN5, CN6, CN8 and CN9, as detailed in the following tables.
Table 1: Interconnections between the STM32 Nucleo board and the X-NUCLEO-NFC04A1
expansion board (left side)
Signal
Connector
Pin
number
STM32 Nucleo board
(MCU port)
X-NUCLEO-NFC04A1
expansion board
NC
CN6 Power
1
-
-
IOREF
2
-
3V3
RESET
3
-
-
3V3
4
-
3V3
5V
5
-
-
GND
6
-
GND
GND
7
-
GND
VIN
8
-
-
A0
CN8
1
PA0
-
a
available even when RF is disabled
b
Table 2: "Interconnections between the STM32 Nucleo board and the X-NUCLEO-NFC04A1 expansion
c
To program the microcontroller on the STM32 Nucleo board refer to user manuals UM1724," STM32 Nucleo-64
board", and UM1725, "Description of STM32F4 HAL and LL drivers", available on www.st.com.