ST25R100 Read Operation

SametKorur · ‎2025-07-03

Hi,
I am running ST25R100 on a different processor and coding it at the register level. With the codes I shared below, I was able to run the chip in wakeup mode as I wanted and ensure that an interrupt occurs when the card is approached. However, I could not succeed in the second stage, which is reading the card. How can I do it, which registers should I write to, please help

Brian TIDAL · ‎2025-07-03

Hi,

Could you clarify what you mean by "reading the card"? Are you referring to retrieving the tag's unique identifier (UID) or reading the memory content of the tag? Additionally, which type of tag are you referring to: T2T, T3T, T4AT, T4BT, or T5T?

I recommend using the RF Abstraction Layer (RFAL) available in the ST25 Embedded Library and porting it to your nRF environment. It is portable and scalable C code.

Rgds

BT

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SametKorur · ‎2025-07-04

Hello, I have a card that I bought online and I don't know the type of it. I just want to read the UID, can you give me the codes for reading it in the simplest way?

It seems very difficult to integrate the Rfal library to a different processor.

If you could help me read the card only, I would be very happy, thank you

Brian TIDAL · ‎2025-07-04

Hi,

You can retrieve NFC tag information using applications such as ST25NFCTap or TagInfo on Android™ phones. This tag seems to comply with the ISO/IEC 14443-3 standard.

In this case, the ST25R100 must be configured in NFC-A/ISO14443 mode. The RF field must be enabled, and the various ISO14443-3 commands (such as REQA or WUPA, followed by ANTICOLLISION and SELECT) must be sent to the tag to retrieve the UID components. These functionalities are available in the RFAL.

The RFAL is designed to be portable across various microcontrollers. All platform-specific dependencies are isolated in macros. If an RTOS such as Zephyr is used, porting examples are available online. For instance, refer to the GitHub repository Zephyr driver for the ST25R NFC reader IC for the ST25R3916, which can serve as a basis for the ST25R100.

Regards

BT

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