nfcpy

Capability Containers & NDEF MAGIC NUMBER

Asked by Phil Burrows

Device: SCL3711
OS: Ubuntu 12.10

When trying to use a type 4 tag with tagtool, I get:

sudo python tagtool.py
searching for a usable reader
searching for a usb bus reader
using SCM Micro SCL3711-NFC&RW at usb:007:002
touch a tag
capability container not found
Type4Tag ATQ=4403 SAK=20 UID=045b1e71981b80

When trying to use a type 2 tag with tagtool, I get:

sudo python tagtool.py
searching for a usable reader
searching for a usb bus reader
using SCM Micro SCL3711-NFC&RW at usb:007:002
touch a tag
while reading ndef: wrong ndef magic number
Type2Tag ATQ=4400 SAK=00 UID=045ec32ada2880

I have tried googling these errors but nothing comes up. Is it something to do with the cards I am using?

Much appreciated
Phil

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Phil Burrows
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Revision history for this message
Phil Burrows (phil-birminghamfoe) said : 		#1

A more verbose log for the type 4:

polling for NFC-A technology
InListPassiveTarget
>>> 0000ff04fcd44a0100e100
<<< 0000ff00ff00
<<< 0000ff15ebd54b010103442007045d5571981b800675778102802100
NFC-A target found at 106 kbps
NFC-A configured for TT4
ATS = 067577810280
found target {'SAK': 32, 'type': 'TT4', 'UID': bytearray(b'\x04]Uq\x98\x1b\x80'), 'ATQ': 17411}
select file
tt4_exchange
InDataExchange
>>> 0000ff10f0d4400100a4040007d2760000850101006d00
<<< 0000ff00ff00
<<< 0000ff05fbd5410067008300
select file
tt4_exchange
InDataExchange
>>> 0000ff0ff1d4400100a4040007d27600008501006e00
<<< 0000ff00ff00
<<< 0000ff05fbd5410090005a00
select file
tt4_exchange
InDataExchange
>>> 0000ff0af6d4400100a4000002e1036100
<<< 0000ff00ff00
<<< 0000ff05fbd541006a82fe00
capability container not found
Type4Tag ATQ=4403 SAK=20 UID=045d5571981b80

Revision history for this message
Phil Burrows (phil-birminghamfoe) said : 		#2

A more verbose log for the type 2:
polling for NFC-A technology
InListPassiveTarget
>>> 0000ff04fcd44a0100e100
<<< 0000ff00ff00
<<< 0000ff0ff1d54b010100440007045ec32ada2880c200
NFC-A target found at 106 kbps
NFC-A configured for TT2
found target {'SAK': 0, 'type': 'TT2', 'UID': bytearray(b'\x04^\xc3*\xda(\x80'), 'ATQ': 17408}
read block #0
tt2_exchange
InDataExchange
>>> 0000ff05fbd440013000bb00
<<< 0000ff00ff00
<<< 0000ff13edd54100045ec3112ada288058480000000000006800
while reading ndef: wrong ndef magic number
Type2Tag ATQ=4400 SAK=00 UID=045ec32ada2880

Revision history for this message
Stephen Tiedemann (stephen-tiedemann) said : 		#3

Your tags are fine but not yet NDEF formatted. So what you have at the moment is a Mifare Ultralight (or similar) and an ISO 14443-4 tag but they need a special data structure to become NFC Forum Type 2 / 4 tags. The nfcpy tagtool can create a type 2 tag format but only with a fixed layout for 120 byte tags. A lot better, and also working with type 4 tags, is the NXP TagWriter app for Android, choose that if you can.

/Stephen

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Phil Burrows (phil-birminghamfoe) said : 		#4

Thanks Stephen

Revision history for this message
Phil Burrows (phil-birminghamfoe) said : 		#5

Sadly I don't have access to an Android that has NFC enabled, so I downloaded and installed libfreefare and ran the mifare-desfire-create-ndef command.
It has formatted it perfectly and now works with nfcpy :-)