Problem after programming/setting tags [CLOSED]

It was just a hardware failure, i bought fresh new good quality cards & now i don't have any problems.

are you using the Adafruit-PN532 library?

can you add a #define MIFAREDEBUG at the begining of your code, ensure Serial is activated and connected to your computer and run a test? you should be able to see some debug info when you try to read the card

Im using the Elechouse libary from Github.

I can read other tags fine, just when i set a password & remove it again from a NXP MIFARE Ultralight - C (NTAG216) nfc-tag, i'm not able to get anything read by the reader anymore from this tag.

Should i try using the Adafruit libary with this reader?

Should i try using the Adafruit libary with this reader?

you could to see if there is a different behavior. they have example code you can run to dump the content of the card if I remember correctly - so see if that reads an pwd protected card

in the library you point to they say

C library for Arduino This is an Arduino library for PN532 to use NFC technology. It's based on Adafruit_NFCShield_I2C , improved by Seeed Studio, added HSU(High Speed Uart) driver by Elechouse.

but their code is 2 year old whereas the Adafruit one has been updated a few months ago

If i use the Adafruit Libary, it does not detect the reader itself.

Hello! TIMEOUT! Didn't find PN53x board


I also removed the password several times & tryd to completely reset the tag with the function from the NFC-Tools app, i tested it before & after and got the same result.

After adding a password, the tag is no longer readable for the reader.

Every other device can read & write to the tag just fine.


This is not a joke or something, i really don't understand it. It's "crazy"?

If i place BOTH cards on top of each other & hold them to the reader, then the card is still getting detected. Also sometimes if i really try it hard, the reader detects in after 30-40 trys. I tested this with multiple cards/tags & all the same happens after the password set/remove process with the NFC-Tools Android App.

I also removed the line "nfc.setPassiveActivationRetries(0xFF);" from the iso14443a_uid example sketch.

// Set the max number of retry attempts to read from a card // This prevents us from waiting forever for a card, which is // the default behaviour of the PN532. nfc.setPassiveActivationRetries(0xFF);