Near Field Communication (NFC) Hardware and Porting#

This page describes the reference ST25R NFC stack shipped with the Aliro extension and how to replace it with a different NFC reader integrated circuit (IC).

Architecture#

Aliro reader code that depends on the NFC frontend is vendor-neutral:

Access protocol (reader.cpp) and NFC transport (nfc.cpp) call AliroNfcFrontend(), which returns the single INfcFrontend implementation linked into the project.
Exactly one Simplicity SDK Component (SLC) component must provide: aliro_nfc_driver. The SLC solver rejects two providers.

The frontend must implement NFC-A polling and ISO 14443-4 Data Exchange Protocol (ISO-DEP) Application Protocol Data Unit (APDU) half-duplex exchange. Minimum requirements are:

NFC-A poller, one device at a time
ISO-DEP activation and transceive
APDU payloads up to 512 bytes
Interruptible waits: blocked WaitForTag() / SendMessage() must return DRIVER_REINIT_REQUESTED promptly when RequestReinit() is called

Reference ST25R Stack#


Component	Provides / requires	Contents
`aliro_nfc_driver_api`	`provides: aliro_nfc_driver_api`	`INfcFrontend`, `aliro_nfc_config.h`
`aliro_nfc_driver_st25r`	`provides: aliro_nfc_driver`	`St25rNfcFrontend` (RFAL wrapper), ST eval analog config
`st25r200` or `st25r300`	RFAL library	Vendored ST sources (mutually exclusive)
`aliro_platform`	Board hardware abstraction layer (HAL)	`platform_spi`, `platform_gpio`, `platform_timer`, pin map
`aliro_reader_transport_nfc`	`requires: aliro_nfc_driver`	Sets `ALIRO_READER_TRANSPORT_NFC`

Typical NFC .slcp fragment:

- id: aliro_reader_transport_nfc
  from: aliro
- id: aliro_nfc_driver_st25r
  from: aliro
- id: st25r200
  from: aliro
- id: spidrv_usart
  instance: [exp]- id: aliro_reader_transport_nfc
  from: aliro
- id: aliro_nfc_driver_st25r
  from: aliro
- id: st25r200
  from: aliro
- id: spidrv_usart
  instance: [exp]

ST NFC Library Components#

The Aliro extension ships ST25RFAL as Simplicity SDK components. No separate ST NFC SDK extension is required.


Component	ST ICs	Evaluation board
ST25R200	ST25R200 / ST25R100	X-NUCLEO-NFC10A1
ST25R300	ST25R300 / ST25R500	X-NUCLEO-NFC12A1

Install exactly one component matching your hardware. Aliro Minimal Reader and AliroMatterLock NFC templates include st25r200 by default.

Select ST25R200 or ST25R300#

Open the project in Simplicity Studio.
Select Software Components → Aliro → NFC Drivers.
Install ST25R200 or ST25R300 matching your board.
If other ST NFC components are present, remove them.

Preprocessor defines are added automatically:

ST25R200: #define ST25R200 1
ST25R300: #define ST25R300 1 and #define ST25R500 1

Port Checklist (Custom IC)#

Implement INfcFrontend.
See aliro/aliro_actuator/hw_driver/nfc_frontend/nfc_frontend.h. Methods: Start(), Init(), Disconnect(), WaitForTag(), SendMessage(), ReceiveMessage(), RequestReinit().

Provide the factory in your driver source.

namespace aliro { namespace hw_driver {
  static AcmeNfcFrontend gAcme;
  INfcFrontend & AliroNfcFrontend() { return gAcme; }
}}namespace aliro { namespace hw_driver {
  static AcmeNfcFrontend gAcme;
  INfcFrontend & AliroNfcFrontend() { return gAcme; }
}}

Ship an SLC component.

For example, aliro_nfc_driver_acme.slcc.

id: aliro_nfc_driver_acme
provides:
  - name: aliro_nfc_driver
requires:
  - name: aliro_nfc_driver_api
  - name: aliro_platform
source:
  - {path: .../acme_nfc_frontend.cpp}id: aliro_nfc_driver_acme
provides:
  - name: aliro_nfc_driver
requires:
  - name: aliro_nfc_driver_api
  - name: aliro_platform
source:
  - {path: .../acme_nfc_frontend.cpp}

Wire the bus and pins.
The reference uses Serial Peripheral Interface (SPI) through platform_spi_* and pin-tool entries in platform_config.h (ST25R_IRQ, ST25R_RST, ST25R_SS). Inter-Integrated Circuit (I2C) or UART frontends can use a parallel bus binding without changing INfcFrontend.
Swap project components.
Replace aliro_nfc_driver_st25r and st25r200/st25r300 with your driver (and drop spidrv_usart if SPI is not used).

No changes to aliro_actuator, the reader loop, or Matter integration code are required.

BLE-Only Builds#

Projects that use the Bluetooth Low Energy (BLE) transport component aliro_reader_transport_ble do not include any NFC driver, ST RFAL, or spidrv_usart components. NFC transport source (nfc.cpp) is excluded at compile time.

Hardware Setup#

See Hardware and Setup for supported boards and the EFR32MG24 ↔ ST25R pin map.