Develop Reference

C# - Bluetooth LE DevicePicker with Custom Filter

I'm trying to add a custom filter to my DevicePicker using System.ItemNameDisplay
I've been searching the internet, finding examples, and testing different implementations but nothing has worked
I can use any of the built in DeviceSelectors from the BluetoothLEDevice class and they work fine but for my specific application I need the DevicePicker to only show devices whose name starts with a certain string [ProductNameStart] where [ProductNameStart] is a hard-coded string representing the starting characters of the devices I want to include on the DevicePicker
I've looked through this example (specifically Scenario 6) and it claims that the AQS can be used in the DevicePicker but doesn't show how.
I also created another project using DeviceWatcher and that works exactly like I intended using this constructor
string deviceFilter = "System.ItemNameDisplay:~<\"[ProductNameStart]\"";
string[] rp = { };DeviceWatcher deviceWatcher = DeviceInformation.CreateWatcher(deviceFilter,rp,DeviceInformationKind.AssociationEndpoint);
I've tried the following implementations for DevicePicker with no luck
DevicePicker devicePicker = new DevicePicker();
//devicePicker.RequestedProperties.Add("System.ItemNameDisplay"); // Doesn't help anything
//devicePicker.Filter.SupportedDeviceSelectors.Add("System.ItemNameDisplay:~<\"[ProductNameStart]\""); // Doesn't Work
//devicePicker.Filter.SupportedDeviceSelectors.Add(BluetoothLEDevice.GetDeviceSelectorFromDeviceName("System.ItemNameDisplay:~<\"[ProductNameStart]\"")); // Doesn't Work
//devicePicker.Filter.SupportedDeviceSelectors.Add(BluetoothLEDevice.GetDeviceSelectorFromDeviceName("[ProductNameStart]")); // Doesn't Work
//devicePicker.Filter.SupportedDeviceSelectors.Add(BluetoothLEDevice.GetDeviceSelectorFromDeviceName(":~<\"[ProductNameStart]\"")); // Doesn't Work
//devicePicker.Filter.SupportedDeviceSelectors.Add(BluetoothLEDevice.GetDeviceSelectorFromDeviceName("~<\"[ProductNameStart]\"")); // Doesn't Work
//devicePicker.Filter.SupportedDeviceSelectors.Add(BluetoothLEDevice.GetDeviceSelectorFromDeviceName("\"[ProductNameStart]\"")); // Doesn't Work
Resources:
SO Posts:
Bluetooth LE Enumeration with DevicePicker issue
AQS syntax when providing a filter for BLE scanning in UWP
Other Posts:
Displaying the device picker in a UWP application
Build a device selector
Using Advanced Query Syntax Programmatically
UWP: Working with Bluetooth devices (part 1)

Detecting bluetooth signal strength from RSSI on Windows

I'm trying to understand how I might access the RSSI of a Bluetooth (not LE) connection in either C# or C++ on Windows.
My understanding is that there is no straightforward "GetRSSI()" type command but is there any indirect way to access it?
Everything I've found so far seems to be aimed at LE connections.
Edit:
I've had a look into AEPs and tried to get the SignalStrength AEP from a connected BT device.
foreach (var key in deviceInformation.Properties.Keys)
{
Debug.WriteLine($"{key}: {deviceInformation.Properties.GetValueOrDefault(key)}");
}
Gives:
System.ItemNameDisplay: <ommitted>
System.Devices.DeviceInstanceId:
System.Devices.Icon: C:\Windows\System32\DDORes.dll,-2001
System.Devices.GlyphIcon: C:\Windows\System32\DDORes.dll,-3001
System.Devices.InterfaceEnabled:
System.Devices.IsDefault:
System.Devices.PhysicalDeviceLocation:
System.Devices.ContainerId:
With the item name omitted by me.
So it looks like there are no AEPs, unless I'm missing something?

I know this is late, but I just started a new project where I also want information about the SignalStrength for Bluetooth (not LE) devices.
#Mike-Petrichenko was giving you some good hints. After following his advice of searching for "System.Devices.Aep.SignalStrength" I found this post
After going throw the OPs Code and debugging a little, I came up with this solution:
private const string SignalStrengthProperty = "System.Devices.Aep.SignalStrength";
var additionalProperties = new[] { SignalStrengthProperty };
DeviceWatcher mWatcher = DeviceInformation.CreateWatcher(BluetoothDevice.GetDeviceSelector(), additionalProperties);
var rssi = Convert.ToInt16(deviceInformation.Properties[SignalStrengthProperty]);

using an Audio Endpoint other than 'DefaultAudioEndpoint' in C#

This program is an audio visualizer for an rgb keyboard that listens to windows' default audio device. My audio setup is a bit more involved, and I use way more than just the default audio device. For instance, when I play music from Winamp it goes through the device Auxillary 1 (Synchronous Audio Router) instead of Desktop Input (Synchronous Audio Router) which I have set as Default. I'd like to be able change the device that the program listens to for the visualization.
I found in the source where the audio device is declared; Lines 32-36 in CSCoreAudioInput.cs:
public void Initialize()
{
MMDevice captureDevice = MMDeviceEnumerator.DefaultAudioEndpoint(DataFlow.Render, Role.Console);
WaveFormat deviceFormat = captureDevice.DeviceFormat;
_audioEndpointVolume = AudioEndpointVolume.FromDevice(captureDevice);
}
The way that I understand it from the documentation, the section MMDeviceEnumerator.DefaultAudioEndpoint(DataFlow.Render, Role.Console) is where Windows gives the application my default IMMEndpoint "Desktop Input."
How would I go about changing DefaultAudioEndpoint?
Further Reading shows a few ways to get an IMMDevice, with DefaultAudioEnpoint being one of them. It seems to me that I'd have to enumerate the devices, and then separate out Auxillary 1 (Synchronous Audio Router) using PKEY_Device_FriendlyName. That's a bit much for me, as I have little to no C# experience. Is there an easier way to go about choosing a different endpoint? Am I on the right track? or am I missing the mark completely?
Also, what is the difference between MMDevice and IMMDevice? The source only seems to use MMDevice while all the Microsoft documentation references IMMDevice.
Thanks.

I DID IT!
I've found why the program uses MMDevice rather than IMMDevice. The developer has chosen to use the CSCore Library rather than Windows' own Core Audio API.
From continued reading of the CSCore MMDeviceEnumerator Documentation, it looks like I'll have to make a separate program that outputs all endpoints and their respective Endpoint ID Strings. Then I can substitute the DefaultAudioEndpoint method with the GetDevice(String id) method, where String id is the ID of whichever Endpoint I chose from the separate program.
To find the the Endpoint I wanted, I wrote this short program to find all the info I wanted:
static void Main(string[] args)
{
MMDeviceEnumerator enumerator = new MMDeviceEnumerator();
MMDeviceCollection collection = enumerator.EnumAudioEndpoints(DataFlow.Render,DeviceState.Active);
Console.WriteLine($"\nNumber of active Devices: {collection.GetCount()}");
int i = 0;
foreach (MMDevice device in collection){
Console.WriteLine($"\n{i} Friendly name: {device.FriendlyName}");
Console.WriteLine($"Endpoint ID: {device.DeviceID}");
i++;
}
Console.ReadKey();
}
This showed me that the Endpoint I wanted was item number 3 (2 in an array) on my list, and instead of using GetDevice(String id) I used ItemAt(int deviceIndex).
MMDeviceEnumerator enumerator = new MMDeviceEnumerator();
MMDeviceCollection collection = enumerator.EnumAudioEndpoints(DataFlow.Render,DeviceState.Active);
MMDevice captureDevice = collection.ItemAt(2);
However in this case, the program was not using captureDevice to bring in the audio data. These were the magic lines:
_capture = new WasapiLoopbackCapture(100, new WaveFormat(deviceFormat.SampleRate, deviceFormat.BitsPerSample, i));
_capture.Initialize();
I found that WasapiLoopbackCapture uses Windows' default device unless changed, and the code was using DefaultAudioEndpoint to get the properties of the default device. So I added
_capture.Device = captureDevice;
//before
_capture.Initialize();
And now the program properly pulls the audio data off of my non-default audio endpoint.

I had been asked to solve a similar type of problem this week. Although there are a few librarys to do this I was specifically asked to do this for "non ish" programmers so I developed this in PowerShell.
Powershell default audio device changer - Github
Maybe you can alter it to your needs.

Detect barcode scanner with PointOfService on Windows 10

I would like to use a barcode scanner with Windows 10 (Build 15063) via the Windows.Devices.PointOfService namespace. The scanner is a Datalogic Quickscan QD2430 and I tried with all RS-232 and Keyboard mode.
I used the official sample application https://github.com/Microsoft/Windows-universal-samples/tree/master/Samples/BarcodeScanner with no luck. It can detect a device but it's definitely the in-built webcam (HP laptop).
I tried to modify the source, the DeviceHelpers's GetFirstDeviceAsync function https://github.com/Microsoft/Windows-universal-samples/blob/master/SharedContent/cs/DeviceHelpers.cs.
The DeviceInformation.FindAllAsync also returns only the camera's info as result.
string selector = BarcodeScanner.GetDeviceSelector(PosConnectionTypes.All);
DeviceInformation.FindAllAsync(selector);
It returns nothing.
DeviceInformation.FindAllAsync(DeviceClass.ImageScanner);
It returns every connected and I think the previously connected but currently offline devices too. I tried to filter the scanner by name. There was a lot filterd result too, but the convertAsync function returned null for all excepts one, it thrown an Exception "A device attached to the system is not functioning. (Exception from HRESULT: 0x8007001F)".
DeviceInformationCollection infos = await DeviceInformation.FindAllAsync(DeviceClass.All);
foreach(DeviceInformation info in infos)
{
if (info.Name.ToUpper().Contains("BARCODE"))
{
T scanner = await convertAsync(info.Id);
if (scanner != null)
{
return scanner;
}
}
}

Datalogic Quickscan QD2430 is not in the list of devices supported by Windows.Devices.PointOfService.
Ask Datalogic to provide a device driver that supports Windows.Devices.PointOfService, or change the scanner to the one described in the supported list.
Alternatively, create your own device driver according to the Point of Service (POS) of Windows Driver Kit.

Playing Audio in .Net / C#

I'm an experienced MFC programmer of many years, who for the more recent years has been developing commercial apps in Objective C for Mac and iOS - I'm trying to get up to speed with .Net and C# (as I'm soon going to be required to convert one of my commercial apps from Mac to PC).
I've now worked my way through a couple of books and as an exercise to get more familiar with .Net (and C#) I've decided to have a go at converting one of my none commercial apps to .Net as a learning exercise and all is going well (interface is working, data structures all good) but I need to be able to play audio.
My Mac app generates audio from a series of mathematical formula - imagine a wave generator - not quite the same but similar. On the Mac I generate the audio as 16 bit signed raw audio, use Core Audio to setup audio output routing and then get a callback whenever a new buffer of audio is required for the audio routing (so I can generate the audio on the fly).
I need to do the same on the PC. Unfortunately I find MSDN documentation to be a case of "Can't see the wood for the trees" as there is such a vast amount of documentation. I can find classes that will let me load and play mp3/wav etc files, but I need to generate the audio realtime. Can anyone point me in the right direction to find something that will allow me to fill buffers on the fly as it plays them?
Thx

I have used this sample in several projects with good results. It is basically a .Net wrapper for Windows Waveform Audio API using P/Invoke.
Other choices:
NAudio
Sound Player class from .Net framework

I have created a class that can play audio given Stream derivate as an input. So if you are able to pack your sound-generator into the Stream compatible interface, it could be suitable for you.
How I did it - I used unmanaged waveOut* methods from old Windows multimedia API, and handled the playback from there.
Other options - that I am aware of - use waveOut directly, from this: http://windowsmedianet.sourceforge.net/ or write your own DirectShow source filter, but that might be too complicated, since it has to be written in c++.
If you are interested in giving my component a try, I can make it available to you at no charge, since I need it beta tested (I only used it in several of my projects).
EDIT:
Since there are 6 upvotes to the question, I am offering my component free of charge (if you find useful) here: http://dl.dropbox.com/u/10020780/SimpleAudioPlayer.zip
Maybe you can reflect on it :)

I use Audiere to accomplish this and find it works very well.
It's a C++ lib really, but there are a set of bindings available for C#.
For more info, see the question I asked.

You should have a look at FMOD which allows this kind of operation and much more. It is also cross platform which can be interested if you are also working on a mac.

Alvas.Audio has 3 audio players: Player
player.FileName = "123.mp3";
player.Play();
PlayerEx
public static void TestPlayerEx()
{
PlayerEx plex = new PlayerEx();
plex.Done += new PlayerEx.DoneEventHandler(plex_Done);
Mp3Reader mr = new Mp3Reader(File.OpenRead("in.mp3"));
IntPtr format = mr.ReadFormat();
byte[] data = mr.ReadData();
mr.Close();
plex.OpenPlayer(format);
plex.AddData(data);
plex.StartPlay();
}
static void plex_Done(object sender, DoneEventArgs e)
{
if (e.IsEndPlaying)
{
((PlayerEx)sender).ClosePlayer();
}
}
and RecordPlayer
public static void TestRecordPlayer()
{
RecordPlayer rp = new RecordPlayer();
rp.PropertyChanged += new PropertyChangedEventHandler(rp_PropertyChanged);
rp.Open(new Mp3Reader(File.OpenRead("in.mp3")));
rp.Play();
}
static void rp_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
switch (e.PropertyName)
{
case RecordPlayer.StateProperty:
RecordPlayer rp = ((RecordPlayer)sender);
if (rp.State == DeviceState.Stopped)
{
rp.Close();
}
break;
}
}