Issue detecting card, ST25R3916B, with RFAL STSW-ST25RFAL002, FreeRTOS Polling

raj-muniraju · ‎2024-11-14

Hello!

I am working on integrating ST25R3916B into our product based on PSOC 6 CM4. I can read the ID and initialization seems to succeed but I cannot detect any tags.

Setup:
* I am using STEVAL-ST25R3916B reader expansion board with ST25R3916B.

* I have VBUS connected 5V, 3.3v to 3v3. SPI pins are properly connected and can read the ID. IRQ as +ve edge.

* I have attached spi transaction logs, I have the SPI bus connected to the logic analyzer in case if need any transaction through the logic analyzer.

* I have attached rfal_platform.h and have ST25R_COM_SINGLETXRX enabled and spi_transfer handles the SS pin.

Please let me know anything to try, not sure where to start.

Ulysses HERNIOSUS · ‎2024-11-18

Hi,

25MHz will not be possible with ST25R3916B. Please check the DS. Fortunately in your trace the SPI is rather at 1.6MHz.

Looking at the trace I find the IRQ pin staying high typically for ~6ms before getting cleared. The timeout handling is happening around <2ms but ISR seems to kick in only after 6ms.

Changing the timeouts is exactly just covering the underlying problems. The values should be fixed and are done in a way that they should pass if proper timer abstraction and interrupt handling is in place.

Regards, Ulysses

raj-muniraju · ‎2024-11-19

Hi @Ulysses HERNIOSUS
Thank you for all the help.
I have removed the RC filter on the GPIO lines, and I am now able to see the interrupts faster and detect tags.

Here is the working trace for anyone's reference.