Can't instantiate a new GattDeviceService - c#

I'm new to Bluetooth LE, and I'm trying to write to a Bluetooth HID device.
I'm using Visual Studios 2015 and am building a WPF application.
currently my code looks like this:
var hidDevices = await DeviceInformation
.FindAllAsync(GattDeviceService.GetDeviceSelectorFromUuid(
GattServiceUuids.HumanInterfaceDevice));
GattDeviceService bleDevice = await GattDeviceService.FromIdAsync(hidDevices[0].Id);
I have some code after, but my code stops right after I try to create a new GattDeviceService.
I know hidDevices[0] is occupied, but the ID generated shows up like this:
\\?/BTHLEDEVICE#{00001812-xxxx-xxxx-xxxx-xxxxxxxxxxxx}_Dev_VID&.........
I'm curious if that is normal.

GATT API does not allow you access HID Services.
I found information about your problems:
Bluetooth GATT—Windows.Device.Bluetooth.Gatt
The API lets Windows Store app developers implement GATT client
profiles for collecting data from low energy (LE) sensors.
A Bluetooth 4.0 radio is required to use the GATT API.
The GATT API prevents access to the following in-box and invalid
services:
(Bluetooth SIG name) 0x1812 HID Over GATT Service
For more informations: https://msdn.microsoft.com/en-us/library/windows/apps/bg182882.aspx

Related

Is it possible to connect to a BTLE device in a WPF application?

So I am trying to connect to a Polar H7 Heart Rate Monitor, and I need to use a WPF application to do it. I'm using Windows 10.
Now I have done this with a UWP application already and it works perfectly, but I'd like to use WPF (if it is possible) instead to do the same.
I found this post on how to use Windows 10 APIs in WPF/winforms/etc and thought perfect, that's what I need. I successfully added the Bluetooth API to my WPF project and threw in the code that was working for my UWP project, but it doesn't work.
Here's a snippet of my code up to where it stops working:
DeviceInformation _devicePolar = null;
string StatusInformation;
string StatusInformation2;
var devices = await DeviceInformation.FindAllAsync(GattDeviceService.GetDeviceSelectorFromUuid(GattServiceUuids.HeartRate));
foreach(var d in devices)
{
Debug.WriteLine(d.Name + " " + d.Id);
}
if (null == devices || devices.Count <= 0) return;
foreach (var device in devices.Where(device => device.Name == "Polar H7 DCB16C16"))
{
_devicePolar = device;
StatusInformation = string.Format("Found {0}", _devicePolar.Name);
break;
}
if (_devicePolar == null) return;
var service = await GattDeviceService.FromIdAsync(_devicePolar.Id);
if (service == null) return;
Now, this call
await GattDeviceService.FromIdAsync(_devicePolar.Id)
is returning null. I was actually having the same problem when I made the UWP application and I found out it was because I forgot to throw in this
<Capabilities>
<Capability Name="internetClient" />
<DeviceCapability Name="bluetooth" />
</Capabilities>
Into my manifest file. Once I put that in (on my UWP application) it worked fine. But there seems to be no equivalent place for this piece in a WPF application. Now going back to the blog post on how to add Win 10 libraries to WPF, this bit seems to be telling me that was the case all along:
The second set of APIs that you can’t use are ones that depend on an app’s package identity. UWP apps have package identities while PC software does not. Package identity information can be found in the app manifest file.
And looking further into the Microsoft topic linked in the post it does specify about Bluetooth that "Not all APIs are currently supported for packaged apps." Which is terribly non-specific.
Also should mention, before trying this I tried to use the 32feet library, but my device was not showing up at all while other devices (not LE) were, so I am assuming that 32feet just doesn't support BTLE. I found this asking the same about 32feet and that is what led me to try what I have detailed above instead, but I'm still not 100% clear on whether or not I can simply use 32feet to connect to BTLE devices.
So my question is, am I right that what am I trying to do (WPF application using Windows 10 API to connect to Bluetooth device) can't currently be done? If not, what am I doing wrong?
Update after two years the question posted: I think there's still no library supporting WPF Bluetooth LE. A pretty straight forward proof is that, Windows settings, which is under UWP, supports Bluetooth LE devices, while Control Panel on Windows 10 doesn't.
The only solution I can come up with now is buying a Bluetooth dongle which has virtual COM port feature, so ideally I can talk to the BLE device like using serial connection. Haven't tested yet, will update later if this works.

Windows RT (r-pi IoT 10) HID device

I am trying to use a HID (DualShock 4) connected to my R-PI 3 running Windows 10 IoT in a C# universal app. I was using the Device Enumeration sample as a guideline and managed to display the IDs of all connected devices. I could see that the connected DualShock was correctly enumerated because it logged the \\?\HID#VID_054C&PID_05C4....
So naturally the next thing I wanted to do was opening the device for communication. Since it is an HID I was using the HidDevice class with var device = await HidDevice.FromIdAsync(args.Id, FileAccessMode.ReadWrite);. Sadly the returned device is always null, nothing on the screen is prompted or so.
Next I assumed there at least has to be some kind of USB interface accessible so I went for var device = await UsbDevice.FromIdAsync(args.Id);
But now I am getting A device attached to the system is not functioning. (Exception from HRESULT: 0x8007001F) or sometimes also The process cannot access the file because it is being used by another process.
How can I talk to my device? :(

How to access two different services from the same ble device

For example, I have two heart rate monitors paired with my tablet PC.
I'm using such code to get list of HRM devices:
var devices = await Windows.Devices.Enumeration.DeviceInformation.FindAllAsync
(
GattDeviceService.GetDeviceSelectorFromUuid(GattServiceUuids.HeartRate)
);
Then I show a listbox in GUI with device names got from devices[i].Name.
For example, I select device with index 0. Then I can get access to it HR serivice and HRM characteristic:
var service = await GattDeviceService.FromIdAsync(devices[0].Id);
var characteristic = await service.GetCharacteristics(attCharacteristicUuids.HeartRateMeasurement);
Along with heart rate I need a battery status. How can I get access to battery service of the same (already selected) device?
Some information before we start:
You do have to pair your Bluetooth devices with your computer, before you could scan them!
Listing your paired devices:
ListBox1.Items.Clear();
var devices = await DeviceInformation.FindAllAsync(RfcommDeviceService.GetDeviceSelector(RfcommServiceId.SerialPort));
foreach (var device in devices)
{
ListBox1.Items.Add(device);
}
If you want to know the battery life of the Bluetooth device:
How to get the battery level after connect to the BLE device?
To access multiple services at once, you need to "reconnect" to the device:
Device A can connect only one at a time to service S on Device B. Device A can connect to service S on Device B, C, D and E, etc at the same time.
#alanjmcf
Source: Establishing multiple bluetooth SPPs at the same time
But do not get confused with the method GetAllIncludedServices();, because it does really return "included services". As one answer stated at an other question:
You probably don't want to get the "included services". Included services is a special concept in BLE which I doubt you are using that is used to link one service from another.
#Emil

32Feet.Net connecting to Bluetooth speakers

So I am trying to connect a bluetooth speakers from a script. I am using 32feet.net and I have successfully found the device but it doesn't work when I try to pair and connect to it.
This is the code im using to pair to device, this always fails not sure why:
private static void connected(BluetoothDeviceInfo[] dev)
{
// dev[foundIndex];
bool paired=false;
paired = BluetoothSecurity.PairRequest(dev[foundIndex].DeviceAddress, "1166");
if (paired)
Console.WriteLine("Passed, Device is connected.");
else
Console.WriteLine("Failed....");
}
Here is the code called after connected to actually connect to the device: bc is my bluetooth client var.
bc.BeginConnect(devInfo[foundIndex].DeviceAddress, BluetoothService.SerialPort, new AsyncCallback(Connect), devInfo[foundIndex]);
private static void Connect(IAsyncResult result)
{
if (result.IsCompleted)
{
Console.Write("Connected... ");
}
}
Any help would be appreciated. I am new to 32feet.net so i dont know much about this, i tried following code online to get where im at.
Try BluetoothDeviceInfo.SetServiceState. That will ask Windows to connect to the audio service on the device -- hopefully that'll do the job.
See https://32feet.codeplex.com/wikipage?title=Connecting%20to%20Bluetooth%20Services
Sometimes we don’t want our application to itself send data to/from a remote service but we want instead the local operating system to do so. This is the case for keyboard/mouse/etc with HID, networking with DUN/NAP/PAN/etc, Headset/Handsfree etc.
and then
The short answer in this case is to use BluetoothDeviceInfo.SetServiceState. This is the API equivalent to manually checking the respective checkbox on the “Services” tab of the Device dialog in Bluetooth Control panel.
Also, in these days of Secure Simple Pairing, using PairRequest is fine only if all peer devices will use old style PIN code authentication, otherwise instantiate a BluetoothWin32Authentication and then do the connect (here indirectly via SetServiceState) and handle the authentication in the authentication callback.

How to connect the WiiMote internally in a C# app?

I want to connect a single wiiMote to my app using WiiMoteLib, but I want the connection done internally ie. the user has only to run the app (and should have no need to connect the wiiMote with windows wizard or bluesoleil). The app is in C# and the language cannot be changed.
Thanks!
Does 32feet.NET do the job?
BluetoothAddress addr = ... address from discovery or known address...
var dev = new BluetoothDeviceInfo(addr);
dev.SetServiceState(BluetoothService.HumanInterfaceDevice, true); // this line!
You may also need to handle pairing, perhaps using BluetoothWin32Authentication and handling its callback, see http://32feet.codeplex.com/wikipage?title=Bluetooth%20Security and http://32feet.codeplex.com/wikipage?title=BluetoothWin32Authentication
There is an example of how to do this here using the Microsoft Bluetooth API and the HID API:
http://www.richlynch.com/code/wiipair
It works quire well.
Its in C++, but its pretty easy to convert to C#.

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