10Pcs NFC Smart Card Reader Tag Tags S50 IC 13.56MHz IC Copier Read Write White Cards
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After I received these, I found out that my smartphone (Samsung Galaxy S5 Neo) did not work with these tags (it says "NFC tag type not supported") After some googling I understand why. The NXP Mifare Classic chips in these tags use a NXP proprietary encryption method, which means they do not strictly conform to the NFC Forum specifications, and can only be read and written by a smartphone if it has an NFC reader chip made by NXP. This was not really a problem in the past, but nowadays more and more smartphones integrate other makes of NFC reader chip. If you need NFC tags that are supported by all smartphones, check if they have a type of chip that does conform to the NFC Forum specs, such as NTAG 203. If you search Banggood for "NFC Tag" you will find a couple of SKU's that have this chip, according to their description (do not search for NTAG 203 or NTAG203, most will not turn up in the search results)
Great price for a small quantity of S50 13.56MHz cards. Had no problem programming and using these for building access as a spare set of keys.