iOS Question Reading UID from NFC Card

[Nicolás Cieri]

Hi, is posible to read the UID from the iPhone?

Something like that...

I saw in the documentation of the library that it is not possible, but that is 5 years old, will it be possible now or not yet?

Thanks.

 

[Erel]

I've tested this code with ndef tag:

Public Sub Scan (DialogMessage As String)
    NFC.Scan(DialogMessage)
    Wait For NFC_TagConnected (Success As Boolean, Tag As Object)
    If Success Then
        Try
            Dim InternalTag As NativeObject = Tag.As(NativeObject).GetField("_tag")
            Log(InternalTag)
            Dim uid As NativeObject = InternalTag.GetField("_uid")
            Dim b() As Byte = uid.NSDataToArray(uid)
            Dim bc As ByteConverter
            Log("uid: " & bc.HexFromBytes(b))
        Catch
            Log("failed to read uid")
            Log(LastException)
        End Try

Based on: https://www.b4x.com/android/forum/threads/nfcex-class-write-ndef-tags.110726/#content

 

[Erel]

BTW, this solution is based on private API. Apple might reject your app and it might break in the future.

 

[Nicolás Cieri]

Thanks Erel!... I'm trying to read an NFC card, but when I hold the card close to the iPhone, it never detects anything.

 

[Nicolás Cieri]

nfc.Supported = true, but never detects anything.

 

[Nicolás Cieri]

I think is a problema of apple.

NFC Tags won't read after iOS 15.4… | Apple Developer Forums

developer.apple.com

 

[Nicolás Cieri]

If I scan with this method:

[IMG alt="Alexoconnor"]https://discussions.apple.com/public/assets/avatars/SYSTEM_DEFAULT_AVATAR.svg[/IMG]
Alexoconnor
User level:Level 1

13 points
Nov 1, 2021 12:10 PM in response to lobsterghost1

1. On your iPhone, open the Shortcuts app.
2. Tap on the Automation tab at the bottom of your screen.
3. Tap on Create Personal Automation.
4. Scroll down and select NFC.
5. Tap on Scan.
6. Put your iPhone near the NFC tag.
7. Enter a name for your tag.
8. Tap on Add Action.

from https://discussions.apple.com/thread/253186716

I can scan, but not with my app. and not also with other apps like "NFC"

 

[Nicolás Cieri]

maybe we need to add another permission?

 

[Erel]

I've tested it with an iOS 16 device. You need to use NDEF tags.

 

[Nicolás Cieri]

"nfc tools" for iphone don't work either. only the shortcuts app Works.

 

[Nicolás Cieri]

Hello, I am trying to get the UID but it gives me very different things.

Any idea? Thanks a lot.

uid: 0816BD0BF10E5C67

 

[Erel]

No idea. Sorry.

I think that it will be safer to write your own unique id and read is as a regular ndef message.

 

[Nicolás Cieri]

Apparently you need to implement a protocol or interface for the type of tag. NFCISO15693Tag

NFCISO15693Tag | Apple Developer Documentation

An interface for interacting with an ISO 15693 tag.

developer.apple.com