Getting started with ST25R3916-DISCO

Introduction

The ST25R3916-DISCO is a ready-to-use development kit designed to evaluate the features and functionality of the ST25R3916, a high-performance NFC universal device for contactless applications. It supports reader/writer, peer-to-peer, and card emulation modes.

The kit comprises two boards:

• MB1396 (ST25_Discovery_Mboard): A microprocessor motherboard featuring a 32-bit STM32 microcontroller (STM32L476 line, Arm Cortex-M4 core with FPU). It includes an ST-LINK in-circuit debugger/programmer, a 2.4" TFT LCD with touch screen, LEDs, push buttons, and USB connectors for power and debugging. It is powered via USB.
• MB1414 (ST25R3916_Discovery_DB): A daughter board embedding the ST25R3916 device, an antenna etched on the PCB, and its tuning circuit. A switch allows selection between 3.3 V and 5 V RF powering.

The two boards communicate via the SPI bus, with the processor card supplying power. Specific data lines also connect the boards.

This kit enables users to develop and test NFC applications through various demonstrations. Schematics, Bill of Materials (BOM), Gerber files, drivers, and firmware for both boards are available on the STMicroelectronics website (www.st.com).

Features

• ISO 18092 (NFCIP-1) active and passive initiator and target modes
• NFC Forum NFC-A, NFC-B, NFC-F, and NFC-V reader
• ISO 14443A, ISO 14443B, and ISO15693 reader
• FeliCa™ reader
• Support for all five NFC Forum Tag types in reader mode
• NFC Forum Type 3 tag (NFC-F) host card emulation
• NFC Forum Type 4A tag (NFC-A) host card emulation
• Stream modes for implementing other standard and custom protocols
• Integrated capacitive sensing system for low-power tag presence detection
• Integrated inductive sensing system for low-power tag presence detection using phase or amplitude measurement
• High output power
• User-selectable and automatic gain control
• Serial Peripheral Interface (SPI) up to 10 Mb/s
• I2C up to 400 kbit/s (Fast-mode), 1 Mb/s (Fast-mode Plus)
• Automatic Antenna Tuning (AAT) via variable capacitor

Description

The ST25R3916-DISCO kit facilitates the evaluation of ST25R devices, a series of high-performance HF readers. The kit includes application notes, software, drivers, BOM, board schematics, and firmware, all downloadable from www.st.com to aid design efforts.

The kit consists of two boards:

1. MB1396 (ST25_Discovery_Mboard): This motherboard features an STM32L476 32-bit microcontroller based on the Arm Cortex-M4 core. It is powered via USB and includes an ST-LINK debugger/programmer, a 2.4" TFT LCD with touch screen, LEDs, push buttons (reset and user), a mini USB debug connector, a user-dedicated micro USB connector, and features for ST NFC TAG.
2. MB1414 (ST25R3916_Discovery_DB): This daughter board incorporates the ST25R3916, an etched antenna, and a tuning circuit. A switch allows for selecting 3.3 V or 5 V RF powering.

Quick start

3.1 Getting started in standalone mode

Ensure the motherboard and daughter board are connected. The default jumper configuration is set at delivery. Power the kit via the micro USB port. The unit requires a safety extra-low voltage (SELV) limited power source through the USB port (max 60 VDC / 8A / 100VA). Upon power-up, the microcontroller runs the pre-loaded firmware, enabling demonstrations of the ST25R3916's capabilities, including reader/writer, card emulation, peer-to-peer communication, automatic antenna tuning, and USB mode.

No modifications or configurations are needed for the demonstration. For more details, refer to the firmware's user manual on the STMicroelectronics website.

3.2 Getting started with USB mode

Connect the discovery kit to a PC using a micro USB cable. The PC's USB port must supply at least 250 mA at 5 V. Download and install the control software from www.st.com. For operating instructions and GUI details, consult UM2511, the "ST25R3916-DISCO kit user manual", available on www.st.com.

3.3 System requirements

• Micro USB cable
• USB port capable of delivering at least 250 mA at 5 V (1.25 W)
• SELV limited power source via USB port
• For embedded ST link and STM32 Nucleo ecosystem development, a mini USB cable is required

MB1396 hardware

The motherboard's PCB connects to the PC via USB. Embedded firmware controls the STM32 MCU, which operates the ST25R3916 through extension connectors. Both boards are powered by the 5 V USB supply, with an LDO converting it to 3.3 V for the microcontroller and ST25R3916. The extension board can be supplied with 3.3 V or 5 V. A green LED near the motherboard's micro USB port indicates power status.

4.1 MB1396 board layout

Key components and connectors on the MB1396 board include:

• ST link USB connector
• User USB connector
• SW bus (STlink)
• ST link activity LED
• Reset button
• User button
• User LED
• Extension connectors
• Powering options jumpers (JP13, JP14, JP15, JP16)
• WiFi® status LED
• WiFi® SW update
• Power 3.3 V LED
• Joystick
• WiFi® reset button
• Extension connector GPIO setting

Table 1. Powering options

4.2 MB1396 jumper default configuration

This section details the default jumper configuration (recommended setting) for the MB1396, which is set at kit delivery. These settings ensure the USB micro connector powers the kit.

Table 2. Jumpers configuration

4.3 MB1396 software development configuration

This section describes the MB1396 software development configuration and USB connection when using the embedded ST link. The J1 USB micro connector provides power, while the J2 USB mini facilitates data exchange with the computer.

MB1414 hardware

5.1 ST25R3916

The ST25R3916 is directly connected to the filtered 5 V USB supply, with additional supply filtering components near the NFC/HF reader IC. Decoupling capacitors are placed close to the ST25R3916 chip. Two capacitive sensing electrodes are on the PCB for demonstrating the capacitive wake-up feature. Serial resistors for SPI cross-connection can be removed and CN100 used. By default, SPI is the access bus; I2C can be used by changing jumpers J200-J205. J206 allows bypassing internal regulators for output currents above 350 mA.

5.2 Antenna and matching network components

This board includes the matching network and automatic antenna tuning capacitors utilizing varicaps.

5.3 Board layout

The MB1414 board features:

• ST25R3916 NFC chip
• RF powering selection switch (3.3 V or 5 V)
• RF front-end area
• Capacitive sensing electrodes

Schematics

This section contains schematics for both boards:

• MB1396 MCU motherboard schematics (Figures 9 to 18) include the microcontroller for the NFC reader IC.
• MB1414 ST25R3916 daughter board schematics (Figures 19 to 21) show its connection to the ST25_Discovery_Mboard motherboard.

Federal Communications Commission (FCC) and Industry Canada (IC) compliance statements

7.1 FCC Compliance Statement

Part 15.19

This device complies with Part 15 of the FCC Rules. Operation is subject to two conditions: (1) it may not cause harmful interference, and (2) it must accept any interference received, including interference that may cause undesired operation.

Part 15.21

Any changes or modifications not expressly approved by STMicroelectronics may cause harmful interference and void the user's authority to operate this equipment.

FCC ID

FCC ID: YCPR3916DB1

7.2 Formal notices required by the Industry Canada (“IC”)

7.2.1 Compliance Statement

This device complies with Industry Canada licence-exempt RSS standard(s). Operation is subject to two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation.

7.2.2 Declaration de Conformité

Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes: (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement.

7.2.3 IC ID

IC ID: 8976A-R3916DB1

Revision history

Table 3. Document revision history