PC/SC in Qt NFC

PC/SC support is provided using native APIs on macOS and Windows, and using PCSCLite library on other platforms. The API can be used for accessing both wired and wireless smartcards and storage cards.

Limitations

• The current API does not provide means to distinguish between separate readers/slots.
• NDEF access is only provided for NFC Type 4 tags.
• Other applications starting transactions on cards may block Qt applications from using Qt Nfc API.
• QNearFieldTarget::sendCommand() used with a PC/SC target starts a transaction that remains active until QNearFieldTarget::disconnect() is called. This transaction prevents other applications from accessing this target.
• The backend is polling for new tags, that means that there may be a delay up to the full polling interval before new tags are reported. The default polling interval is 100 milliseconds. It can be adjusted by setting environment valiable QT_NFC_POLL_INTERVAL_MS to an integer value in milliseconds.