Discover and connect a reader

Discovery finds the reader, gets USB permission, and hands you a ReaderInfo you turn into a session. See Device discovery for the model.

Start discovery and collect readers

val manager = sdk.startReaderDiscovery()
 
viewModelScope.launch {
    manager.readers.collect { readers ->
        _uiReaders.value = readers          // render a picker
    }
}
viewModelScope.launch {
    manager.readerErrors.collect { e ->
        _uiError.value = e.message          // "why is there no reader?"
    }
}

readers only contains permissioned readers. An empty list with no readerErrors means nothing is plugged in.

Request permission

For SecuGen / BioMini, the manifest device_filter triggers the system dialog on attach. For EADAK / Aratek (and as a catch-all), call requestPermissions() when your activity receives the attach intent:

// MainActivity
override fun onNewIntent(intent: Intent) {
    super.onNewIntent(intent)
    if (intent.action == UsbManager.ACTION_USB_DEVICE_ATTACHED) {
        manager.requestPermissions()   // shows the dialog for readers lacking permission
    }
}

Observe manager.permissionGranted to enable the “connect” UI once permission is in place.

Open a session

val reader = manager.readers.value.firstOrNull() ?: return
val session = sdk.createFingerprintReaderSession(reader.id)

createFingerprintReaderSession throws a CaptureError if discovery hasn’t started or no reader with that id is connected — guard on a non-empty readers list first.

[!TIP] The reference demo (demo/) implements this exact pattern with an app-scoped holder that owns SladeID + ReaderManager — copy it as a starting point.

Clean up

Call sdk.release() when you’re done to unregister the receiver and close reader handles.

Used in

• Enroll a fingerprint
• Troubleshooting