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kiliankoe / MensaDresden

🌯 See what's for lunch at Dresden's canteens
https://apps.apple.com/us/app/mensa-dresden/id1481891701?ls=1
MIT License
27 stars 6 forks source link

How deos Emeal scanning work? #68

Closed simonmeusel closed 4 years ago

simonmeusel commented 4 years ago

This is just a question. If you don't have time to answer it, just close it :)

How does the Emeal NFC scanning work? Why do other raw NFC communication apps not show the card? Is it a special standard or does your app somehow communicate with the tag (seems like this in the source code)? Can you give me some pointers on where I can get further information?

simonmeusel commented 4 years ago

See #17

kiliankoe commented 4 years ago

Hi Simon,

I struggled with this a bit as well. The basic idea is that Emeals (like other MiFare cards) aren't like NFC NDEF tags in that they just store some data which can be read, but they run their own operating system (which sounds pretty fancy for a plastic card) that can respond to certain commands which are written onto the card by the reader.

There must be some documentation on how this works somewhere, but my implementation is largely adapted from schorschii/MensaGuthaben-iOS.

Sorry I can't be of too much help regarding any more information, but please feel free to share anything else you might come across here. I'd love to know more about this as well 😄

kiliankoe commented 4 years ago

I'm going to go ahead and close this as it's not really an issue per se, but feel free to keep the conversation going.

simonmeusel commented 4 years ago

Some links:

[0] https://de.wikipedia.org/wiki/Mifare [1] https://en.wikipedia.org/wiki/ISO/IEC_14443 [2] https://developer.apple.com/documentation/corenfc/nfcmifaretag [3] https://www.mifare.net/support/forum/topic/documentation-desfire-ev1/

The documentation for the MiFare cards seems to be restricted to their customers [3].