We are developing an iOS app that communicates with a device using an NXP NTAG 5 chip in ISO15693 pass-through mode. While the app works flawlessly on older iPhone models (iPhone 8, SE, X) and most Android devices, we are experiencing severe reliability issues on iPhone 12, 13, 14, and 15.
Issue Summary
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On newer iPhones (12–15), 90% of communication attempts fail.
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Retry strategies do not work, as the NFC session is unexpectedly canceled while handling CoreNFC custom commands.
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The issue is not consistent—sometimes all requests fail immediately, while other times, a batch of reads might succeed unexpectedly before failing again.
Technical Details
The failure occurs while executing the following request, which should return 256 bytes:
tag.customCommand(requestFlags: .highDataRate, customCommandCode: commandCode, customRequestParameters: Data(byteArray)) { (responseData, error) in
}
The returned error is:
-[NFCTagReaderSession transceive:tagUpdate:error:]:897 Error Domain=NFCError Code=100 "Tag connection lost" UserInfo={NSLocalizedDescription=Tag connection lost}
For reference, we tested a comparable STM ST25 chip in ISO15693 and NDEF mode, and the exact same issue occurs.
Observations and Debugging Attempts
- Positioning of the NFC antenna has been tested extensively.
- Disabling Bluetooth and Wi-Fi does not improve reliability.
- Rebooting the device or waiting between attempts sometimes improves success rates but does not provide a structural fix.
- When reading multiple blocks (e.g., 15 blocks of 256 bytes each):
- The process often fails within the first three blocks.
- After multiple failures, it may suddenly succeed in reading all blocks in one go before returning to a series of failures.
The nfcd logs suggest issues at the low-level NFC and SPMI layers, indicating potential hardware or firmware-related problems:
error 17:36:18.289099+0100 nfcd phOsalNfc_LogStr:65 NCI DATA RSP : Timer expired before data is received!
error 17:36:18.292936+0100 nfcd NFHardwareSerialQuerySPMIError:1339 "Invalid argument" errno=22 setsockopt: SYSPROTO_CONTROL:IO_STOCKHOLM_SPMIERRORS
error 17:36:18.293036+0100 nfcd phTmlNfc_SpmiDrvErrorStatus:1157 "Invalid argument" errno=22 Failed to query SPMI error registers
error 17:36:18.293235+0100 nfcd phOsalNfc_LogStr:65 phLibNfc_SpmiStsRegInfoNtfHandler: Read Spmi Status Failed - pInfo set to NULL
error 17:36:18.293313+0100 nfcd _Callback_NFDriverNotifyGeneral:2353 Unknown notification: 0x5b
error 17:36:18.294163+0100 nfcd phOsalNfc_LogStr:65 Target Lost!!
error 17:36:18.294678+0100 nfcd -[_NFReaderSession handleSecureElementTransactionData:appletIdentifier:]:164 Unimplemented
error 17:36:18.294760+0100 nfcd -[_NFReaderSession handleSecureElementTransactionData:appletIdentifier:]:164 Unimplemented
error 17:36:18.320132+0100 nfcd phOsalNfc_LogStr:65 ISO15693 XchgData,PH_NCINFC_STATUS_RF_FRAME_CORRUPTED Detected by NFCC during Data Exchange
error 17:36:18.320291+0100 nfcd phOsalNfc_LogU32:74 phNciNfc_ChkDataRetransmission: Re-transmitting Data pkt Attempt..=1
error 17:36:18.622050+0100 nfcd phOsalNfc_LogStr:65 NCI DATA RSP : Timer expired before data is received!
error 17:36:18.625857+0100 nfcd NFHardwareSerialQuerySPMIError:1339 "Invalid argument" errno=22 setsockopt: SYSPROTO_CONTROL:IO_STOCKHOLM_SPMIERRORS
error 17:36:18.625919+0100 nfcd phTmlNfc_SpmiDrvErrorStatus:1157 "Invalid argument" errno=22 Failed to query SPMI error registers
error 17:36:18.626132+0100 nfcd phOsalNfc_LogStr:65 phLibNfc_SpmiStsRegInfoNtfHandler: Read Spmi Status Failed - pInfo set to NULL
error 17:36:18.626182+0100 nfcd _Callback_NFDriverNotifyGeneral:2353 Unknown notification: 0x5b
error 17:36:18.626899+0100 nfcd phOsalNfc_LogStr:65 Target Lost!!
error 17:36:18.627482+0100 nfcd -[_NFReaderSession handleSecureElementTransactionData:appletIdentifier:]:164 Unimplemented
error 17:36:18.627568+0100 nfcd -[_NFReaderSession handleSecureElementTransactionData:appletIdentifier:]:164 Unimplemented
error 17:36:18.833174+0100 nfcd -[_NFReaderSession handleSecureElementTransactionData:appletIdentifier:]:164 Unimplemented
error 17:36:19.145289+0100 nfcd phOsalNfc_LogStr:65 NCI DATA RSP : Timer expired before data is received!
error 17:36:19.149233+0100 nfcd NFHardwareSerialQuerySPMIError:1339 "Invalid argument" errno=22 setsockopt: SYSPROTO_CONTROL:IO_STOCKHOLM_SPMIERRORS
error 17:36:19.149353+0100 nfcd phTmlNfc_SpmiDrvErrorStatus:1157 "Invalid argument" errno=22 Failed to query SPMI error registers
error 17:36:19.149730+0100 nfcd phOsalNfc_LogStr:65 phLibNfc_SpmiStsRegInfoNtfHandler: Read Spmi Status Failed - pInfo set to NULL
error 17:36:19.149797+0100 nfcd _Callback_NFDriverNotifyGeneral:2353 Unknown notification: 0x5b
error 17:36:19.150463+0100 nfcd phOsalNfc_LogStr:65 Target Lost!!
Any solutions?
Has anyone else encountered similar behavior with CoreNFC on iPhone 12–15? Could this be related to changes in NFC hardware or power management in newer iPhone models? Any suggestions on possible workarounds or alternative approaches would be greatly appreciated.
