JavaCard OS

I have received the MIFARE DESFire EV1 D81 cards, but I don't know how to start. I wonder if i can download an applet on it just like a java card. If yes, which tool should I use? Thanks.

You cannot download an applet on a DESFire card.

If that is the case, how can I write data into DESFire card? Is there any samples?

You can use libfreefare https://github.com/nfc-tools/libfreefare or check ridrix blog https://ridrix.wordpress.com/2009/09/19 ... n-example/ for Mifare Desfire communication example

rena2019 wrote:You can use libfreefare https://github.com/nfc-tools/libfreefare or check ridrix blog https://ridrix.wordpress.com/2009/09/19 ... n-example/ for Mifare Desfire communication example

Great library and example. I will start with these guides. Thank you so much, rena2019.

You's better check MIFARE DESFire EV1 architecture first to know how the data is managed on DESFire card.

This may helps:
http://www.nxp.com/documents/short_data ... 81_SDS.pdf