I am using pn532 nfc controller for a project on rfid and it was working well. I use uart to communicate with it(pn532). but for a reason I haven't figured out yet its uart stops working; it stops to respond to the commands I send to it using uart. I know the nfc controller (pn532) is not dead/damaged totally because it working when connected through SPI.
so please help me on figuring out what makes its uart to stop working.