Reading NFC tags, cannot get UID

[Rokas]

Hello,

I'm trying to make a communication with a nrf51822 and an trf7970a nfc reader. The communication is based on SPI, I read that there are problems with softdevices enabled, so I tryed to turn it of, but it still doesn't give me wanted results. I had a check on all the pins that if they are initialized and the correct ones are picked, and the volteges droped on every pin - looks good. It looks like the spi is working, sending commands I get a NRF_SUCCESS response. But trying to get an ID of the tag, I get nonsense, after checking the memory address I get all zeros where the tag ID should be, and a uncompleted state. Did anyone have anything simmilar to this?

[Hung Bui]

I would suggest to post your question on TI forum.

Before trying to get the ID of a Tag, you should better try to write/read registers and FIFO inside the TRF7970 just to make sure you can communicate to the TI chip correctly.