Android Question Wait For Connected Bluetooth always fail

Public Sub DirectPrint(aPrinter As String, aData As String, aBTMac As String)
    Dim PairedDevices As Map
    LocalOSerial.Initialize("DirectPrint")
    If aBTMac = "" Then
        PairedDevices = LocalOSerial.GetPairedDevices
        For i = 0 To PairedDevices.Size - 1
            Dim device As String = PairedDevices.GetKeyAt(i)
            If device.Contains(aPrinter) Then
                LogColor("yBTPrinter.DirectPrint "&aPrinter, Colors.Red)
                LocalBTMac = PairedDevices.get(device)
            End If
        Next
        If LocalBTMac = "" Then
            Return
        End If
    Else
        LocalBTMac = aBTMac
    End If

    LocalOSerial.Connect(LocalBTMac)

    Wait For DirectPrint_Connected (Success As Boolean)

    If Success Then
        LocalPrinter.Initialize(LocalOSerial.OutputStream)
        LocalPrinter.WriteLine(LocalData)
        LocalPrinter.Flush
        LocalPrinter.Close
    Else
        LogColor("Fail to Connect", Colors.Red)
    End If
    LocalOSerial.Disconnect
End Sub