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UWP Bluetooth LE InvalidCastException

i want to connect the myo wristband to the hololens. This is the end goal, but I am anyway but close to that :-/
The idea is to set up a Bluetooth LE Connection with UWP.
I wanted to do this, as explanined in this Microsoft Document
The search for the devices workes fine, but when I try to connect to a device, this line (Point "Connecting to the device"
): GattDeviceServicesResult result = await device.GetGattServicesAsync();
raises the error:
System.InvalidCastException: "Unable to cast object of type
'Windows.Devices.Bluetooth.BluetoothLEDevice' to type
'Windows.Devices.Bluetooth.IBluetoothLEDevice3'."
I have no idea what the IBluetoothLEDevice3 has to do there :-)
I was not able to find a solution for this on the microsoft documentation or the internet :-/
I work on Visual Studio 2017, build for Windows 10 (15063) and Bluetooth is enabled in the manifest.
This is my code so fare. I added only one thing and that is the Task. I wanted to make sure, that the BluetoothLEDDevice is not null or anything, since it is not synchron. Without its not working either.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using System.Diagnostics;
using Windows.Devices.Enumeration;
using Windows.Devices.Bluetooth;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using System.Threading.Tasks;
using Windows.Devices.Bluetooth.Advertisement;
// Die Elementvorlage "Leere Seite" wird unter https://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x407 dokumentiert.
namespace Bluetooth17
{
/// <summary>
/// Eine leere Seite, die eigenständig verwendet oder zu der innerhalb eines Rahmens navigiert werden kann.
/// </summary>
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
blue();
}
void blue()
{
// Query for extra properties you want returned
string[] requestedProperties = { "System.Devices.Aep.DeviceAddress", "System.Devices.Aep.IsConnected" };
DeviceWatcher deviceWatcher =
DeviceInformation.CreateWatcher(
BluetoothLEDevice.GetDeviceSelectorFromPairingState(false),
requestedProperties,
DeviceInformationKind.AssociationEndpoint);
// Register event handlers before starting the watcher.
// Added, Updated and Removed are required to get all nearby devices
deviceWatcher.Added += DeviceWatcher_Added;
deviceWatcher.Updated += DeviceWatcher_Updated;
deviceWatcher.Removed += DeviceWatcher_Removed;
// EnumerationCompleted and Stopped are optional to implement.
deviceWatcher.EnumerationCompleted += DeviceWatcher_EnumerationCompleted;
deviceWatcher.Stopped += DeviceWatcher_Stopped;
// Start the watcher.
deviceWatcher.Start();
}
private void DeviceWatcher_Stopped(DeviceWatcher sender, object args)
{
Debug.WriteLine("Stopped");
}
private void DeviceWatcher_EnumerationCompleted(DeviceWatcher sender, object args)
{
Debug.WriteLine("Enum complete");
}
private void DeviceWatcher_Removed(DeviceWatcher sender, DeviceInformationUpdate args)
{
Debug.WriteLine(args.Id + " Removed");
}
private void DeviceWatcher_Updated(DeviceWatcher sender, DeviceInformationUpdate args)
{
Debug.WriteLine(args.Id + " Update");
}
private void DeviceWatcher_Added(DeviceWatcher sender, DeviceInformation args)
{
Debug.WriteLine(args.Id + " " + args.Name);
if (args.Name.Equals("Myo"))
{
Debug.WriteLine("Try to connect to Myo");
getServices(args);
}
}
async Task<BluetoothLEDevice> ConnectDevice(DeviceInformation deviceInfo)
{
Debug.WriteLine("Asyc");
// Note: BluetoothLEDevice.FromIdAsync must be called from a UI thread because it may prompt for consent.
return await BluetoothLEDevice.FromIdAsync(deviceInfo.Id);
}
async void getServices(DeviceInformation deviceInfo)
{
Task<BluetoothLEDevice> task = ConnectDevice(deviceInfo);
task.Wait();
BluetoothLEDevice device = task.Result;
GattDeviceServicesResult result = await device.GetGattServicesAsync();
if (result.Status == GattCommunicationStatus.Success)
{
var services = result.Services;
// ...
}
}
}
}
Thank you

If you target your application to Build 15063 and you know the device you are connecting to than just use:
device = await BluetoothLEDevice.FromBluetoothAddressAsync(blueToothAddress);
This is much more stable than your code and no need for device watcher.
Here is an example that works for my device(not a MIO but a HM10) :
using System;
using System.Diagnostics;
using Windows.Devices.Bluetooth;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using Windows.UI.Xaml.Controls;
namespace App1
{
public sealed partial class MainPage : Page
{
private BluetoothLEDevice device;
GattDeviceServicesResult serviceResult = null;
public MainPage()
{
this.InitializeComponent();
StartDevice();
}
private async void StartDevice()
{
//To get your blueToothAddress add: ulong blueToothAddress = device.BluetoothAddress to your old code.
ulong blueToothAddress = 88396936323791; //fill in your device address!!
device = await BluetoothLEDevice.FromBluetoothAddressAsync(blueToothAddress);
if (device != null)
{
string deviceName = device.DeviceInformation.Name;
Debug.WriteLine(deviceName);
int servicesCount = 3;//Fill in the amount of services from your device!!
int tryCount = 0;
bool connected = false;
while (!connected)//This is to make sure all services are found.
{
tryCount++;
serviceResult = await device.GetGattServicesAsync();
if (serviceResult.Status == GattCommunicationStatus.Success && serviceResult.Services.Count >= servicesCount)
{
connected = true;
Debug.WriteLine("Connected in " + tryCount + " tries");
}
if (tryCount > 5)//make this larger if faild
{
Debug.WriteLine("Failed to connect to device ");
return;
}
}
}
}
}
}

How to C# send AT command to GSM modem and get response

I want to get AT command response.
I want to read SMS from my GSM modem.
I fount some code on google, This script send AT commands but not get response.
This is my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO.Ports;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace CSharp_SMS
{
public partial class Form_SMS_Sender : Form
{
private SerialPort _serialPort;
public Form_SMS_Sender()
{
InitializeComponent();
}
private void buttonSend_Click(object sender, EventArgs e)
{
string number = textBoxNumber.Text;
string message = textBoxMessage.Text;
_serialPort = new SerialPort("COM6", 115200);
Thread.Sleep(1000);
_serialPort.Open();
Thread.Sleep(1000);
_serialPort.WriteLine("AT" + "\r");
Thread.Sleep(1000);
string status = _serialPort.ReadLine();
labelStatus.Text = "|-"+ status + "-|";
_serialPort.Close();
}
}
}
This code is not work.
not get response, but send AT commands.
How to get response?
Thanks

if ECHO is off on your modem, you won't get any response to your AT commands.
Ensure echo is enabled by sending ATE1 first
Thread.Sleep(1000);
_serialPort.WriteLine("ATE1" + "\r");
Thread.Sleep(1000);
_serialPort.WriteLine("AT" + "\r");

celu.RtsEnable = true;
celu.DtrEnable = true;
celu.WriteBufferSize = 3000;
celu.BaudRate = 9600;
celu.PortName = "COM26"; // You have check what port your phone is using here, and replace it
celu.Open();
//string cmd = "AT+CLIP=1"; // Here you put your AT command
//celu.WriteLine(cmd);
celu.WriteLine ("AT+CLIP=1"+"\r");
Thread.Sleep(500);
//celu.Open();
string ss = celu.ReadExisting();

How come I get no output from this piece of code?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Timers;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
Timer time = new Timer();
time.Elapsed += new ElapsedEventHandler(action);
time.Interval = 5000;
time.Enabled = true;
time.Start();
}
static void action(Object sender, ElapsedEventArgs args)
{
Console.WriteLine("haha\n");
}
}
}
This piece of code doesnt have any output. Could anyone tell me what the problem is? Thank you very much. I followed exact code on MSDN.. http://msdn.microsoft.com/en-us/library/system.timers.timer(v=vs.71).aspx

Timer goes out of scope immediately and thus is never called. The program exits before it has a chance to fire the action.
You can make your main method sleep by adding this after time.start():
TimeSpan interval = new TimeSpan(0, 0, 2);
Thread.Sleep(interval);

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Timers;
class Program
{
static void Main(string[] args)
{
while(true)
{
Timer time = new Timer();
time.Elapsed += new ElapsedEventHandler(action);
time.Interval = 100;
time.Enabled = true;
time.Start();
string line = Console.ReadLine(); // Get string from user
if (line == "exit") // Check for exit condition
{
break;
}
}
Console.WriteLine("End of Program\n");
}
static void action(Object sender, ElapsedEventArgs args)
{
Console.WriteLine("haha\n");
}
}

C# Program stops responding after second WebClient.DownloadString()

I am working on a program for proof of concept that does a webrequest using WebClient.DownloadString("http://website/members/login.php?user=" + textBox1.Text + "&pass=" + textBox2.Text);
to get the boolean value of wether or not the user is a valid login and then if it is it gives a success notification if it isn't ten it gives a fail notification.
The problem is when i press the button to try and login the first time it works fine but when i press it again the second tine the program freezes and gets stuck at the Webclient.download string.
If anyone can spot and tell me whats wrong that would be great. I am providing the code below:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Text;
using System.Net;
using System.IO;
using System.Diagnostics;
using System.Net;
using System.Collections;
namespace WindowsFormsApplication2
{
public partial class Form1 : Form
{
public static WebClient webclient = new WebClient();
HttpWebResponse wResp;
WebRequest wReq;
bool isConnected = false;
private String Session = "";
public Form1()
{
InitializeComponent();
}
public Boolean checkUser(String username, String password)
{
String login = `webclient.DownloadString("http://connorbp.info/members/auth.php?user=" + textBox1.Text + "&pass=" + textBox2.Text);`
Boolean bLogin = Boolean.Parse(login);
if (bLogin)
{
Session = username + "-" + password;
}
return bLogin;
}
public int CanConnect(string dUrl)
{
wReq = WebRequest.Create(dUrl);
int cnt = Connect();
return cnt;
}
private int Connect()
{
try
{
wResp = (HttpWebResponse)wReq.GetResponse();
isConnected = true;
return 1;
}
catch (Exception)
{
return 0;
}
}
private void button1_Click(object sender, EventArgs e)
{
int init = CanConnect("http://connorbp.info/members/auth.php");
if (init == 0)
{
notifyIcon1.ShowBalloonTip(200, "CBP Login", "Failed to connect to server! Try again later.", ToolTipIcon.Error);
}
else
{
if(checkUser(textBox1.Text, textBox2.Text))
{
notifyIcon1.ShowBalloonTip(20, "CBP Login", "Logged In!", ToolTipIcon.Info);
}
else
{
notifyIcon1.ShowBalloonTip(20, "CBP Login", "Invalid Username/Password!", ToolTipIcon.Error);
}
}
}
private void Form1_Load(object sender, EventArgs e)
{
this.MaximizeBox = false;
notifyIcon1.ShowBalloonTip(20, "CBP Login", "for more cool things go to http://connorbp.info", ToolTipIcon.Info);
}
}
}

You are not closing the response.
The second call is trying to open something that is already open, therefore it hangs.

when i running the below code iam getting handle is invalid it takes a string and pass it to remote batch file

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.Security;
namespace SampleProject
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
String input = textBox1.Text;
try
{
Process ps = new Process();
ps.StartInfo.FileName = #"\\199.63.55.163\d$\hello.bat";
ps.StartInfo.Arguments = input;
ps.StartInfo.CreateNoWindow = false;
String domain = ps.StartInfo.Domain;
ps.StartInfo.RedirectStandardOutput = true;
ps.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
ps.StartInfo.WorkingDirectory = #"d:\praveen";
ps.StartInfo.UserName = "Raj";
ps.StartInfo.Domain = "domain";
ps.StartInfo.Password = Encrypt("Hello123");
ps.StartInfo.UseShellExecute = false;
ps.Start();
ps.WaitForExit();
MessageBox.Show(ps.StandardOutput.ReadToEnd());
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
private void label1_Click(object sender, EventArgs e)
{
}
public static SecureString Encrypt(String pwd)
{
SecureString ss = new SecureString();
for (int i = 0; i < pwd.Length; i++)
{
ss.AppendChar(pwd[i]);
}
return ss;
}
}
}

It's a shot in the dark, but I think that you can't read the processes standard output once it has exited.
Also you have to redirect it - take a look at this documentation: http://msdn.microsoft.com/en-us/library/system.diagnostics.process.standardoutput.aspx

Duplicate of .NET Process Start Process Error using credentials (The handle is invalid) ? You need to assign RedirectStandardInput, RedirectStandardOutput, RedirectStandardError