Scanning for a Human Interface Device (HID) using C#

Question

I am developing a C# .NET 2.0 application wherein I need to scan for an attached HID. How can this be done? Because it is a HID, Windows does not assign a COM port to it.

Answer 1

Here is an example of enumerating Hid devices on Windows:

    public static ConnectedDeviceDefinition GetDeviceDefinition(string deviceId, SafeFileHandle safeFileHandle)
    {
        try
        {
            var hidAttributes = GetHidAttributes(safeFileHandle);
            var hidCollectionCapabilities = GetHidCapabilities(safeFileHandle);
            var manufacturer = GetManufacturer(safeFileHandle);
            var serialNumber = GetSerialNumber(safeFileHandle);
            var product = GetProduct(safeFileHandle);

            return new ConnectedDeviceDefinition(deviceId)
            {
                WriteBufferSize = hidCollectionCapabilities.OutputReportByteLength,
                ReadBufferSize = hidCollectionCapabilities.InputReportByteLength,
                Manufacturer = manufacturer,
                ProductName = product,
                ProductId = (ushort)hidAttributes.ProductId,
                SerialNumber = serialNumber,
                Usage = hidCollectionCapabilities.Usage,
                UsagePage = hidCollectionCapabilities.UsagePage,
                VendorId = (ushort)hidAttributes.VendorId,
                VersionNumber = (ushort)hidAttributes.VersionNumber,
                DeviceType = DeviceType.Hid
            };
        }
        catch (Exception)
        {
            return null;
        }
    }

Full class here: https://github.com/MelbourneDeveloper/Device.Net/blob/master/src/Hid.Net/Windows/WindowsHidDeviceFactory.cs

API Calls here: https://github.com/MelbourneDeveloper/Device.Net/blob/master/src/Hid.Net/Windows/HidAPICalls.cs

Here is a similar thing for Windows 10 (UWP):

    public async Task> GetConnectedDeviceDefinitions(FilterDeviceDefinition deviceDefinition)
    {
        var aqsFilter = GetAqsFilter(deviceDefinition.VendorId, deviceDefinition.ProductId);

        var deviceInformationCollection = await wde.DeviceInformation.FindAllAsync(aqsFilter).AsTask();

        var deviceDefinitions = deviceInformationCollection.Select(d => GetDeviceInformation(d, DeviceType));

        var deviceDefinitionList = new List();

        foreach (var deviceDef in deviceDefinitions)
        {
            var connectionInformation = await TestConnection(deviceDef.DeviceId);
            if (connectionInformation.CanConnect)
            {
                await Task.Delay(1000);

                deviceDef.UsagePage = connectionInformation.UsagePage;

                deviceDefinitionList.Add(deviceDef);
            }
        }

        return deviceDefinitionList;
    }

Code:https://github.com/MelbourneDeveloper/Device.Net/blob/77439b1ab0f4b3ad97376e4e62c7efac0a749783/src/Device.Net.UWP/UWPDeviceFactoryBase.cs#L47

Android (https://github.com/MelbourneDeveloper/Device.Net/blob/77439b1ab0f4b3ad97376e4e62c7efac0a749783/src/Usb.Net.Android/AndroidUsbDeviceFactory.cs#L31):

    public Task> GetConnectedDeviceDefinitions(FilterDeviceDefinition deviceDefinition)
    {
        return Task.Run>(() =>
        {
            //TODO: Get more details about the device.
            return UsbManager.DeviceList.Select(kvp => kvp.Value).Where(d => deviceDefinition.VendorId == d.VendorId && deviceDefinition.ProductId == d.ProductId).Select(GetAndroidDeviceDefinition).ToList();
        });
    }

Using Hid.Net, you can enumerate devices in the same way on any platform like below. See the full article.

var devices = await DeviceManager.Current.GetConnectedDeviceDefinitions(new FilterDeviceDefinition { VendorId = 0x1209, ProductId = 0x53C1 });
foreach (var device in devices)
{
    Debug.WriteLine(device.DeviceId);
}