Hello,
I am currently working as a student on designing my own hardware for reading and writing NFC tags. Although I lack experience in RF design, I have completed the electronic design and antenna matching process. My setup includes an STM32U575RGTx microcontroller connected to an ST25R3916B NFC chip via SPI. The antenna, sourced from Taoglas, is connected to the matching circuit, and I have confirmed the RF field using a spectrum analyzer.
This project does not utilize the STM HAL; instead, I am working in bare metal. I have developed a HAL for SPI communication, which is functioning without errors. Additionally, I have ported the RFAL library to my project to facilitate interaction with the NFC chip.
At present, I have two types of tags for testing: NFC-A T2T and NFC-V tags. I have enabled the necessary configuration in rfal_platform.h and implemented the example from the X-NUCLEO-NFC08A1 to attempt reading the tags.
However, I am encountering issues. When I try to read the NFC-A tag, the process does not progress past RFAL_NFC_STATE_POLL_COLAVOIDANCE in the rfalWorker() function, and gNfcDev.devCnt remains at 0. In contrast, when I attempt to read the NFC-V tag, the state does not reach RFAL_NFC_STATE_POLL_COLAVOIDANCE; instead, it stays in RFAL_NFC_STATE_POLL_TECHDETECT and fails to detect any tags.
I have a logic analyzer connected to my SPI and IRQ pins and can provide traces if needed.
Do you have any insights into where my error might be?
Thank you in advance for your assistance.
Best regards,
Marc
