What does it mean if I get FF-EE-1F when I tap a contactless card?


First look at the card does it have a NFC/Cotactless symbol? if not, it probably is not a financial payment card for NFC contactless payment. (it could be a Mifare card)


The bast way to figure this out is to parse the unencrypted tags using Parsomatic. The screenshot below shows a Start Contactless command was issued and a card was Tapped and unencrypted tags were returned:


Copy the unencrypted tags to Parsomatic (2) and check the TLVs only checkbox (1), Parse (3) see image below:

Notice tag FF EE 1F (4) shows a Description of Error Code (4 bytes) for contactless and a Value of 30 (5)


In the Table 9 in the NEO IDG (available to developers upon request) defines the value 30 as "Card did not respond" 


This indicates this is not a NFC/Contactless EMV capable card.


To talk to a Mifare card you must put the reader in Bypass Mode (1 ) and then poll for token using send NEO command (2) to send 2C-02 with data value of  of 1A00 (3). If the card responds (5) it is a Mifare card and you will need to know how to work with that type of Mifare card. 


but now you know.