/// <summary>
/// Listen for a connection.
/// </summary>
/// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
public async Task StartListening()
{
try
{
// If already listening, do nothing
if (IsListening)
{
return;
}
// Create device
var deviceInfo = await GetBluetoothDeviceInfo();
device = await BluetoothLEDevice.FromIdAsync(deviceInfo.Id);
device.ConnectionStatusChanged += Device_ConnectionStatusChanged;
// Initiate connection
gattSession = await GattSession.FromDeviceIdAsync(device.BluetoothDeviceId);
gattSession.MaintainConnection = true;
}
catch
{
// Stop the device and rethrow exception
StopListening();
throw;
}
}
private async Task CreateSession( )
{
_session?.Dispose( );
_session = await GattSession.FromDeviceIdAsync(_device.BluetoothDeviceId);
_session.MaintainConnection = true;
}
public async void Connect(string id)
{
try
{
// BT_Code: BluetoothLEDevice.FromIdAsync must be called from a UI thread because it may prompt for consent.
bluetoothLeDevice = await BluetoothLEDevice.FromIdAsync(id);
if (bluetoothLeDevice == null)
{
Log.d("Failed to connect to device.", NotifyType.ErrorMessage);
return;
}
bluetoothLeDevice.ConnectionStatusChanged += ConnectionStatusChangedHandler;
mBluetoothGatt = await GattSession.FromDeviceIdAsync(bluetoothLeDevice.BluetoothDeviceId);
mBluetoothGatt.MaintainConnection = true;
}
catch (Exception ex) when(ex.HResult == E_DEVICE_NOT_AVAILABLE)
{
Log.d("Bluetooth radio is not on.", NotifyType.ErrorMessage);
return;
}
if (bluetoothLeDevice != null)
{
// Note: BluetoothLEDevice.GattServices property will return an empty list for unpaired devices. For all uses we recommend using the GetGattServicesAsync method.
// BT_Code: GetGattServicesAsync returns a list of all the supported services of the device (even if it's not paired to the system).
// If the services supported by the device are expected to change during BT usage, subscribe to the GattServicesChanged event.
GattDeviceServicesResult result = await bluetoothLeDevice.GetGattServicesForUuidAsync(RX_SERVICE_UUID);
if (result.Status == GattCommunicationStatus.Success)
{
_services.Clear();
_services.AddRange(result.Services);
Log.d(String.Format("Found {0} services", _services.Count), NotifyType.StatusMessage);
foreach (var service in _services)
{
Log.d("SERVICE: " + DisplayHelpers.GetServiceName(service));
GetCharachteristics(service);
}
}
else
{
Log.d("Device unreachable", NotifyType.ErrorMessage);
}
}
}
public async void ConnectDevice(ulong addr)
{
string addrString = addr.ToString("X");
Console.WriteLine("{0}: {1}",
addrString, loops.ContainsKey(addr) ? "Updating connection" : "Connecting");
BluetoothLEDevice loop = await BluetoothLEDevice.FromBluetoothAddressAsync(addr);
loop.ConnectionStatusChanged += ConnectionStatusHandler;
// Maintain the connection (not sure this does anything)
//Console.WriteLine("{0}: Maintaining connection ...", addrString);
GattSession s =
await GattSession.FromDeviceIdAsync(BluetoothDeviceId.FromId(loop.DeviceId));
s.MaintainConnection = true;
//Console.WriteLine("{0}: Getting services ...", addrString);
GattDeviceServicesResult serviceResult =
await loop.GetGattServicesAsync(BluetoothCacheMode.Uncached);
foreach (GattDeviceService service in serviceResult.Services)
{
if (service.Uuid.Equals(loopService))
{
//Console.WriteLine("{0}: Finding characteristics ...", addrString);
GattCharacteristicsResult charResult = await service.GetCharacteristicsAsync(BluetoothCacheMode.Uncached);
foreach (GattCharacteristic characteristic in charResult.Characteristics)
{
if (characteristic.Uuid.Equals(loopChar))
{
Subscribe(characteristic, addr);
// Prevent GC of the device and session
loops[addr] = loop;
break;
}
}
}
else if (service.Uuid.Equals(GattServiceUuids.Battery))
{
GattCharacteristicsResult charResult = await service.GetCharacteristicsAsync(BluetoothCacheMode.Uncached);
foreach (GattCharacteristic characteristic in charResult.Characteristics)
{
if (!characteristic.Uuid.Equals(GattCharacteristicUuids.BatteryLevel))
{
continue;
}
GattReadResult batt = await characteristic.ReadValueAsync();
DataReader reader = DataReader.FromBuffer(batt.Value);
byte[] input = new byte[reader.UnconsumedBufferLength];
reader.ReadBytes(input);
Console.WriteLine("Loop battery: {0}%", input[0]);
break;
}
}
}
}