Develop Reference

HidSharp Never Receives Input Report

I'm attempting to use HidSharp to read reports from a Vendor USB HID device using the below code, but I never manage to poll any input.
var device = DeviceList.Local.GetHidDevices().Where(d => /* My Vendor stuff */).First();
var deviceDescriptor = device.GetReportDescriptor();
if (device.TryOpen(out var inputStream))
{
var inputReport = deviceDescriptor.InputReports.First();
var inputReportParser = inputReport.DeviceItem.CreateDeviceItemInputParser();
var inputReportReciever = deviceDescriptor.CreateHidDeviceInputReceiver();
var inputReportBuffer = new byte[inputReport.Length];
while (inputReportReciever.IsRunning)
{
if (inputReportReciever.WaitHandle.WaitOne(10000))
{
while (inputReportReciever.TryRead(inputReportBuffer, 0, out var report))
{
if (inputReportParser.TryParseReport(inputReportBuffer, 0, report))
{
if (inputReportParser.HasChanged)
{
var data = inputReportParser.GetValue(inputReportParser.GetNextChangedIndex());
Console.WriteLine("Data: " + data.ToString());
}
}
}
}
}
}
I can see in the device manager that the device is recognized as an HID USB device, and Wireshark shows that I am sending periodic reports like so:
(I'm a java developer so I'm really struggling with Visual Studio) I can't step in to the library to see what's happening, but there are no errors being thrown and the 'test' included with the project parses reports from at least one other USB device (a headset) so the library seems ok. I'm not at all sure how to proceed with debugging further. Any direction on this library or USB is appreciated.

Android Notification Sound Causes Media Volume to Duck (Lower) & It Never Comes Back

I just converted one of my apps to target Android API 9 (was targeting API 8); now when notifications are sent out, the volume of media is lowered and never comes back to full volume.
The app uses WebView to play media files. This was not happening prior to targeting API 9. I had to convert the app into level 9 so that I could upload to the Google Play Store. I am running a Samsung S7 which was originally designed for API level 6 (with the OS upgraded to 8.0), not sure if that has something to do with the issue. Another detail is that I use Xamarin.Android for development, not sure if that matters either.
Additionally, I forced the notifications to play a blank sound (a very short[couple ms] blank mp3) in the same build that I converted the app to target API 9:
var channelSilent = new Android.App.NotificationChannel(CHANNEL_ID, name + " Silent", Android.App.NotificationImportance.High)
{
Description = description
};
var alarmAttributes = new Android.Media.AudioAttributes.Builder()
.SetContentType(Android.Media.AudioContentType.Sonification)
.SetUsage(Android.Media.AudioUsageKind.Notification).Build()
//blank is blank mp3 file with nothing in it, a few ms in duration
var uri = Android.Net.Uri.Parse("file:///Assets/blank.mp3")
channelSilent.SetSound(uri, alarmAttributes);
...so it could also be the blank sound that is causing the ducking to malfunction, not the API change. Is there something to do with notification sound ducking that could be causing the issue? Is there any other way to mute a notification with Xamarin.Android other than playing a blank sound? That is one route I think would be worth trying to fix this issue.
Here is the code I am using to generate notifications:
private static List<CustomNotification> _sentNotificationList = new List<CustomNotification>();
private static NotificationManagerCompat _notificationManager;
public async void SendNotifications(List<CustomNotification> notificationList)
{
await Task.Run(() =>
{
try
{
var _ctx = Android.App.Application.Context;
if (_notificationManager == null)
{
_notificationManager = Android.Support.V4.App.NotificationManagerCompat.From(_ctx);
}
if (notificationList.Count == 0)
{
return;
}
int notePos = 0;
foreach (var note in notificationList)
{
var resultIntent = new Intent(_ctx, typeof(MainActivity));
var valuesForActivity = new Bundle();
valuesForActivity.PutInt(MainActivity.COUNT_KEY, _count);
valuesForActivity.PutString("URL", note._noteLink);
resultIntent.PutExtras(valuesForActivity);
var resultPendingIntent = PendingIntent.GetActivity(_ctx, MainActivity.NOTIFICATION_ID, resultIntent, PendingIntentFlags.UpdateCurrent);
resultIntent.AddFlags(ActivityFlags.SingleTop);
var alarmAttributes = new Android.Media.AudioAttributes.Builder()
.SetContentType(Android.Media.AudioContentType.Sonification)
.SetUsage(Android.Media.AudioUsageKind.Notification).Build();
//I am playing this blank sound to prevent android from spamming sounds as the notifications get sent out
var uri = Android.Net.Uri.Parse("file:///Assets/blank.mp3");
//if the notification is the first in our batch then use this
//code block to send the notifications with sound
if (!_sentNotificationList.Contains(note) && notePos == 0)
{
var builder = new Android.Support.V4.App.NotificationCompat.Builder(_ctx, MainActivity.CHANNEL_ID + 1)
.SetAutoCancel(true)
.SetContentIntent(resultPendingIntent) // Start up this activity when the user clicks the intent.
.SetContentTitle(note._noteText) // Set the title
.SetNumber(1) // Display the count in the Content Info
.SetSmallIcon(Resource.Drawable.bitchute_notification2)
.SetContentText(note._noteType)
.SetPriority(NotificationCompat.PriorityMin);
MainActivity.NOTIFICATION_ID++;
_notificationManager.Notify(MainActivity.NOTIFICATION_ID, builder.Build());
_sentNotificationList.Add(note);
notePos++;
}
//if the notification isn't the first in our batch, then use this
//code block to send the notifications without sound
else if (!_sentNotificationList.Contains(note))
{
var builder = new Android.Support.V4.App.NotificationCompat.Builder(_ctx, MainActivity.CHANNEL_ID)
.SetAutoCancel(true) // Dismiss the notification from the notification area when the user clicks on it
.SetContentIntent(resultPendingIntent) // Start up this activity when the user clicks the intent.
.SetContentTitle(note._noteText) // Set the title
.SetNumber(1) // Display the count in the Content Info
.SetSmallIcon(Resource.Drawable.bitchute_notification2)
.SetContentText(note._noteType)
.SetPriority(NotificationCompat.PriorityHigh);
MainActivity.NOTIFICATION_ID++;
_notificationManager.Notify(MainActivity.NOTIFICATION_ID, builder.Build());
_sentNotificationList.Add(note);
notePos++;
}
ExtStickyService._notificationsHaveBeenSent = true;
}
}
catch
{
}
});
}
In my MainActivity I've created two different notification channels: one is silent; the other uses default notification setting for the device:
void CreateNotificationChannel()
{
var alarmAttributes = new Android.Media.AudioAttributes.Builder()
.SetContentType(Android.Media.AudioContentType.Sonification)
.SetUsage(Android.Media.AudioUsageKind.Notification).Build();
var uri = Android.Net.Uri.Parse("file:///Assets/blank.mp3");
if (Build.VERSION.SdkInt < BuildVersionCodes.O)
{
// Notification channels are new in API 26 (and not a part of the
// support library). There is no need to create a notification
// channel on older versions of Android.
return;
}
var name = "BitChute";
var description = "BitChute for Android";
var channelSilent = new Android.App.NotificationChannel(CHANNEL_ID, name + " Silent", Android.App.NotificationImportance.High)
{
Description = description
};
var channel = new Android.App.NotificationChannel(CHANNEL_ID + 1, name, Android.App.NotificationImportance.High)
{
Description = description
};
channel.LockscreenVisibility = NotificationVisibility.Private;
//here is where I set the sound for the silent channel... this could be the issue?
var notificationManager = (Android.App.NotificationManager)GetSystemService(NotificationService);
channelSilent.SetSound(uri, alarmAttributes);
notificationManager.CreateNotificationChannel(channel);
notificationManager.CreateNotificationChannel(channelSilent);
}
Full source: https://github.com/hexag0d/BitChute_Mobile_Android_BottomNav/tree/APILevel9
EDIT: something really interesting is that if I pulldown the system ui bar, the volume goes back to normal. Very strange workaround but it might help diagnose the cause.
DOUBLE EDIT: I used .SetSound(null, null) instead of using the blank .mp3 and the ducking works fine now. See comments

Bluetooth BLE Battery Level - C#

I have an specific issue about the Bluetooth BLE API on Windows 10.
At the moment I'm programming a tool on C# (Visual Studio) which connects itself to a given BLE - Device. Currently the connection works perfect and I can read out the ServiceUUIDs and the CharacterUUIDs.
The main Problem is after I try to read the value of the Character its always returns me 00. I heard that implementing a notification will change that and I followed these instructions but they didn't help me.
(Here are the Specifications from bluetooth.com:)
My Code:
//connect to BluetoothDevice
var device = await BluetoothLEDevice.FromIdAsync(address);
//get UUID of Services
var services = await device.GetGattServicesAsync();
if (services != null)
{
foreach (var servicesID in services.Services)
{
//if there is a service thats same like the Battery Service
if (servicesID.Uuid.ToString() == BluetoothBLE.Constants.BATTERY_SERVICE)
{
//updateServiceList is like a console logging in my tool
updateServiceList($"Service: {servicesID.Uuid}");
var characteristics = await servicesID.GetCharacteristicsAsync();
foreach (var character in characteristics.Characteristics)
{
if (Constants.BATTERY_LEVEL == character.Uuid.ToString())
{
updateServiceList("C - UUID: "+ character.Uuid.ToString());
GattReadResult result = await character.ReadValueAsync();
if (result.Status == GattCommunicationStatus.Success)
{
var reader = DataReader.FromBuffer(result.Value);
byte[] input = new byte[reader.UnconsumedBufferLength];
reader.ReadBytes(input);
System.Diagnostics.Debug.WriteLine(BitConverter.ToString(input));
}
}
}
}
After Running my Code, the system logs 00. The characterUUID for battery level (0x2A19, from https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.battery_level.xml) was read successfully but the value is strange..

tranfer file via bluetooth to iphone using 32feet

I am trying to transfer a file to my iphone using 32feet bluetooth, but cannot seem to get past the ObexWebResponse.
I have read many post on this but none of the solutions seem to work for me.
The Error i get is
// Connect failed
// The requested address is not valid in its context "address:Guid"
private BluetoothClient _bluetoothClient;
private BluetoothComponent _bluetoothComponent;
private List<BluetoothDeviceInfo> _inRangeBluetoothDevices;
private BluetoothDeviceInfo _hlkBoardDevice;
private EventHandler<BluetoothWin32AuthenticationEventArgs> _bluetoothAuthenticatorHandler;
private BluetoothWin32Authentication _bluetoothAuthenticator;
public BTooth() {
_bluetoothClient = new BluetoothClient();
_bluetoothComponent = new BluetoothComponent(_bluetoothClient);
_inRangeBluetoothDevices = new List<BluetoothDeviceInfo>();
_bluetoothAuthenticatorHandler = new EventHandler<BluetoothWin32AuthenticationEventArgs>(_bluetoothAutenticator_handlePairingRequest);
_bluetoothAuthenticator = new BluetoothWin32Authentication(_bluetoothAuthenticatorHandler);
_bluetoothComponent.DiscoverDevicesProgress += _bluetoothComponent_DiscoverDevicesProgress;
_bluetoothComponent.DiscoverDevicesComplete += _bluetoothComponent_DiscoverDevicesComplete;
ConnectAsync();
}
public void ConnectAsync() {
_inRangeBluetoothDevices.Clear();
_hlkBoardDevice = null;
_bluetoothComponent.DiscoverDevicesAsync(255, true, true, true, false, null);
}
private void PairWithBoard() {
Console.WriteLine("Pairing...");
bool pairResult = BluetoothSecurity.PairRequest(_hlkBoardDevice.DeviceAddress, null);
if (pairResult) {
Console.WriteLine("Success");
Console.WriteLine($"Authenticated equals {_hlkBoardDevice.Authenticated}");
} else {
Console.WriteLine("Fail"); // Instantly fails
}
}
private void _bluetoothComponent_DiscoverDevicesProgress(object sender, DiscoverDevicesEventArgs e) { _inRangeBluetoothDevices.AddRange(e.Devices); }
private void _bluetoothComponent_DiscoverDevicesComplete(object sender, DiscoverDevicesEventArgs e) {
for (int i = 0; i < _inRangeBluetoothDevices.Count; ++i) {
if (_inRangeBluetoothDevices[i].DeviceName == "Uranus") {
_hlkBoardDevice = _inRangeBluetoothDevices[i];
PairWithBoard();
TransferFile();
return;
}
}
// no devices found
}
private void _bluetoothAutenticator_handlePairingRequest(object sender, BluetoothWin32AuthenticationEventArgs e) {
e.Confirm = true; // Never reach this line
}
// not working
// transfers a file to the phone
public void TransferFile() {
string file = "E:\\test.txt",
filename = System.IO.Path.GetFileName(file);
string deviceAddr = _hlkBoardDevice.DeviceAddress.ToString();
BluetoothAddress addr = BluetoothAddress.Parse(deviceAddr);
_bluetoothClient.Connect(BluetoothAddress.Parse(deviceAddr), BluetoothService.SerialPort);
Uri u = new Uri($"obex://{deviceAddr}/{file}");
ObexWebRequest owr = new ObexWebRequest(u);
owr.ReadFile(file);
// error:
// Connect failed
// The requested address is not valid in its context ...
var response = (ObexWebResponse)owr.GetResponse();
Console.WriteLine("Response Code: {0} (0x{0:X})", response.StatusCode);
response.Close();
}
The pairing and authentication works just fine, and I can get the BluetoothService.Handsfree to make a call for me but the transferring of the file fails. Not knowing what the actual error is, I tried almost every service available with no luck.
Can you help me figure out what is going on? This is my first attempt working with Bluetooth services so I still have a ton to learn.

Is it possible to transfer a file from iPhone to Windows desktop via Bluetooth?
However, in case you need to transfer media files (images, videos, etc) from Android device, you can use ObexListener class provided by 32Feet library for this purpose, and then you can simply call _obexListener.GetContext() method that will block and wait for incoming connections.
Once a new connection is received, you can save the received file to local storage, as shown in the below example:
ObexListener _listener = new ObexListener();
_listener.Start();
// This method will block and wait for incoming connections
ObexListenerContext _context = _listener.GetContext();
// Once new connection is received, you can save the file to local storage
_context.Request.WriteFile(#"c:\sample.jpg");
NOTE: When working with OBEX on Windows, make sure to disable the "Bluetooth OBEX Service" Windows service, in order not to let it handle the incoming OBEX requests instead of the desired application.

I walked away from this for a while. and started Trying to use xamiren but then had to create a virtual Mac so that I could have the apple store to just load software on my phone. From there xamerin 'should' work well but its another field and tons more to firgure out.

Send raw commands to Zebra printer in Windows 10 UWP application

I'm developing an application for Windows 10 to send ZPL commands to a Zebra printer. For the life of me I cannot figure out how to send the raw commands. I can't use the printer dialog box before each print because the app needs to print documents as they come in from an external service. In short: no user intervention.
So far I'm successfully getting the DeviceInformation instance for the printer connected via USB. This is where I'm stuck. Here are the callbacks bound to XAML components for the device selection.
private async void selectPrinter_Click(object sender, RoutedEventArgs e)
{
picker = new DevicePicker();
picker.Filter.SupportedDeviceSelectors.Add("System.Devices.InterfaceClassGuid:=\"{0ecef634-6ef0-472a-8085-5ad023ecbccd}\"");
picker.DevicePickerDismissed += DevicePickerDismissed;
picker.DeviceSelected += DeviceSelected;
Rect rect = new Rect(100, 100, 200, 200);
picker.Show(rect);
}
private async void DeviceSelected(DevicePicker sender, DeviceSelectedEventArgs args)
{
settings.PrinterId = args.SelectedDevice.Id;
device = args.SelectedDevice;
await UpdatePrinterText();
picker.Hide();
}
private async Task UpdatePrinterText()
{
if (device == null)
{
var printerId = settings.PrinterId;
if (!string.IsNullOrWhiteSpace(printerId))
device = await DeviceInformation.CreateFromIdAsync(printerId);
}
await Dispatcher.RunAsync(CoreDispatcherPriority.High, () => printerName.Text = device?.Name ?? "(no printer selected)");
}
I've tried using UsbDevice to send raw commands, but the app errors out with System.IO.FileNotFoundException: 'The system cannot find the file specified. (Exception from HRESULT: 0x80070002)' on var usbDevice = await UsbDevice.FromIdAsync(device.Id); Full code:
private async void printTest_Click(object sender, RoutedEventArgs e)
{
if (device == null)
return;
var usbDevice = await UsbDevice.FromIdAsync(device.Id);
var outPipe = usbDevice.DefaultInterface.BulkOutPipes[0];
var stream = outPipe.OutputStream;
var writer = new DataWriter(stream);
var command = "^XA^FO10,10,^AO,30,20^FDFDTesting^FS^FO10,30^BY3^BCN,100,Y,N,N^FDTesting^FS^XZ";
var buffer = Encoding.ASCII.GetBytes(command);
writer.WriteBytes(buffer);
await writer.StoreAsync();
}
Update: the USB cord had come loose. So I plugged it in, and now UsbDevice.FromAsync is returning null. I guess MS REALLY doesn't want you mucking around with printers...

Sending raw ZPL to printers can be done with the Generic Text based driver.