I don't know if this is the right post but i have one week with one same problem.
I have tested this python code
Inside with one raspberry and one MFRC522, and it works great!, It does the authentication.
I have translated this code to STM32F0, and it get rights the UID but it get MI_NOTAGERROR when I tried to pass the SelectTag step and one MI_ERR when I tried to do the authentication step.
I suppose that the problem was SPI, because I had to translate SPI function from python to STM32F.
I simulated and used Hardware SPI. In both cases I can read register, even I can get right ID but I have problems with SelectTag and Authentication process. It seems that errors are when I tried to send more than 2 bytes to MFRC522_REG_FIFO_DATA.
What is wrong?
Thanks in advance.