Android read actual data from rfid tag

Question

I have a Nexus S and I have specialty RFID writing hardware and passive RFID tags. I can write strings to the RFID tags (and read the strings back using the same hardware) but none of the NFC demo apps on Android I've tried show me the actual string.

What methods would I use to read the actual string byte data from the passive rfid tag? Everything I've looked at just gives me diagnostic information about the tag not the data present on it

The data isn't encrypted to my knowledge, just plain text.

I am not sure if the NDEF standard is usuable on passive RFID tags, the addressing might be different or something. Insight appreciated.

Answer 1

For what you are trying to do, you cannot read your tags using NDEF. NDEF is a format for storing data on your tags, not for the process of reading or writing tags. The issue that you are running into is that the communication protocol you are using (ISO 15693, or NfcV) is not used with any of the tag types that support NDEF Records (Type 1-4). The basic demo apps will try to pass data via NDEF, but don't usually have support for transmitting and receiving raw data using the other standards (I believe they would identify other cards by ID number). You would have to write your own app, to connect to a NfcV card and use the transceive(byte[]) command to send custom coded commands to read and write data.