Connecting to a bluetooth headset programatically - Windows Mobile Development and Hacking General

Hi,
I hope someone can help me !
I'm trying to programatically make a connection to Bluetooth headset from WM5 device.
Using the GU interface provided on the device, I can
a. discover the headset device, and authenicate
b. Select the headset service, however I'm not certain what is actually
done programatically when perform this selection in the GUI
c. Redirect the audio of the WM5 device to the headset.
This all works fine !
Additionally I seen a lot of programs available to direct the audio of the
device thru the headset, but what I'm missing is the code which
allow me to do things which I currently do via the GUI.
I am now trying to do this all programatically, I've been looking through a
description of the headset profile, it seems to indicate that the AG can
initiate a connection to the HS, the AG is responsible for the creation of :
1. Connection establishment
2. SCO link establishment
In the following code, I think :
BthCreateACLConnection & BthAuthenticate are performing 1
BthCreateSCOConnection is performing 2
CreateFile and DeviceIoControl perform c.
if (ERROR_SUCCESS == BthCreateACLConnection (&b, &h)) {
iRes = BthAuthenticate (&b);
BthCloseConnection (h);
int res = BthCreateSCOConnection (&b, &hSCO);
} else {
iRes = GetLastError ();
MessageBox (hWnd, L"Connection failed", L"Error", MB_OK | MB_TOPMOST);
}
HANDLE h = CreateFile(L"BAG0:",0,0,NULL,OPEN_EXISTING,0,NULL);
if (INVALID_HANDLE_VALUE == h) {
// TODO: Handle failure case where AG is not present
}
BOOL fStatus = DeviceIoControl(h,IOCTL_AG_OPEN_AUDIO,NULL,0,NULL,0,NULL,NULL);
if (FALSE == fStatus) {
// Failed to open BT audio!
} else {
// Success!
}
CloseHandle(h);
I'm currently attempting to make to SCO connection to the BT_ADDR of the
device, as opposed to the socket of the headset service. I'm not certain if
this is correct or not. I get an error code 1229 which means :
An operation was attempted on a nonexistent network connection.
Am I doing something wrong !
Cheers
Paul Grant

Related

GPRS

Hi I am very new to C# and compact framework. I have been coding for XDA's using eVB. I want to be able to enable the GPRS mode and also be able to Hangup.
Do I use RasDial? Is this an achievable task for a C# beginer? Could someone please give me some hints as how to achieve this.
Highflyer,
Firstly, why move over to C# when you can achieve what you want using VB.NET. Like yourself, I have ported across an eVB Rasdial app across to .NET CF. Secondly, with GPRS remember that you only pay for the data that is transferred over the connection, so you dont need to worry about the disconnection, but this can be done manually by putting the XDA into FLIGHT MODE. I think you will find another thread covering how to do this programmatically in this forum.
In my app, my XDA is sending and requesting XML packets over HTTP to a web server. To do this I use the HttpWebRequest and HttpWebResponse classes.
Here is a snippet of code
*******************************
Public Function Post(ByVal sURL As String, Optional ByVal strRequest As String = "", Optional ByVal blnRetValExpected As Boolean = False, Optional ByRef strReturned As String = "", Optional ByRef intStatus As Integer = 0) As Boolean
Dim WebReq As HttpWebRequest
Dim WebRes As HttpWebResponse
Dim bOK As Boolean
Try
WebReq = CType(WebRequest.Create(sURL), HttpWebRequest)
If strRequest <> "" Then
Dim encoding As New ASCIIEncoding
Dim byte1 As Byte() = encoding.GetBytes(strRequest)
WebReq.Method = "POST"
WebReq.ContentType = "application/x-www-form-urlencoded"
WebReq.ContentLength = strRequest.Length
Dim newStream As Stream = WebReq.GetRequestStream()
newStream.Write(byte1, 0, byte1.Length)
newStream.Close()
End If
WebRes = CType(WebReq.GetResponse(), HttpWebResponse)
If WebRes.StatusCode = HttpStatusCode.OK Then
bOK = True
End If
intStatus = WebRes.StatusCode
Catch ex As InvalidOperationException
bOK = False
Catch ex As WebException
bOK = False
Catch ex As ProtocolViolationException
bOK = False
End Try
If bOK And blnRetValExpected Then
If WebRes.ContentLength > 0 Then
Dim sResponse() As Byte
Dim ReceiveStream As Stream = WebRes.GetResponseStream()
Dim encode As encoding = encoding.GetEncoding("utf-8")
Dim ReadStream As New StreamReader(ReceiveStream, encode)
Dim strXML As String = ""
Try
strXML = ReadStream.ReadToEnd()
Catch ex As Exception
strXML = ""
bOK = false
Finally
ReadStream.Close()
End Try
strReturned = strXML
End If
End If
WebRes.Close()
Post = bOK
End Function
*******************************
What you will find with the above code is that there is no code for making the GPRS connection and RasDial is no longer required. This is due to the code being hidden away in the HttpWebRequest class and the GPRS connection will use the current connection if it exists or prompt the user for the connection to use. The prompting can be overcome by setting a defualt GPRS connection in Settings - Connection Manager, and saving the password along with it. HTH.
Tony,
Many thanks for your advice. The included sample code is very useful. The problem is I have to stick with C#, wether I like it or not. However I can follow your code to reporoduce something similar in C#. I have already used Post in eVB, to send data, however I changed over to using sockets (WinSock), since I understand there is lower data over head in using sockets. I appreciate any comments you may have with this choice.
One question, you mentioned that when we connect to GPRS we do not pay for actual connection. Is this right, my understanding was when the device connects to GPRS, some data is used to achieve this connection, thus just establishing a connection to GPRS would cost. I am thinking of the situation when GPRS has to be enabled and disabled hundreds of times a day.
Thanks again, looking forward to hear any comments.
Highflyer,
Regarding a connection charge - you may be right about this depending on the type of contract you are on, but as I mentioned once a connection is established you are only charged for the data that is transferred over the connection, so why not leave the connection open then there will only be the one connection charge. If the connection is lost due to poor signal then the underlying code of the web components will re-establish the connection as and when required. HTH.
Thanks for your advice.
I am still very interested to be able to perform RasDial using C#. As I said I have tried to write the code however due to my lack of experience in using C# the code does not work.
Any Ideas or advice anybody.
Thanks
WebRequest on Magician/XDA Mini?
Hi there!
I´m glad finding .NET developers here ;-)
I have a big, big problem:
On several XDA Mini´s (HTC Magician) the HttpWebRequest or WebRequest methods instantly return with an exception (ConnectFailure), even if Pocket IE or other software can reach the net. I´ve tested both, connection via ActiveSync and GPRS, but it does not work.
Any ideas on this? Is it a known issue, and is there a way to solve it?
Thanky in advance,

Minimum code for a network connection

Hi guys,
I've made a simple program that uses google to compare hits on different strings. The program works fine on my computer, but compiling it with the Windows Mobile SDK has been a struggle. Eventually it compiles, but it does not work
I know that the problem has to do with how I am using the Connction Manager functions. I've found a few examples, but they are all pretty big and confusing.
The following did not work at all:
Code:
#include <connmgr.h>
CONNMGR_CONNECTIONINFO sInf;
DWORD dwCurrentStatus, dwStatus;
HANDLE hConnection = NULL;
ConnMgrConnectionStatus(hConnection, &dwCurrentStatus);
if (dwCurrentStatus != CONNMGR_STATUS_CONNECTED)
{
ConnMgrEstablishConnectionSync(&sInf, &hConnection,
30000, &dwStatus);
}
if(dwCurrentStatus != CONNMGR_STATUS_CONNECTED ||
dwStatus != CONNMGR_STATUS_CONNECTED)
AfxMessageBox(L"Not Connected to manager");
What is the minimum code to get my app connected, so that I may use functions like InternetOpenURL?
Any tips, links, guides etc. would be great
Bagera

GetThreadTimes(): PPC vs Smartphone

Does anyone have experience using GetThreadTimes() on Smartphone? I have some code that works fine on PPC (pulls thread cpu usage for all threads), but it can only get the usage of threads for the current process on Smartphone. There's no reference to the platforms having different security models. Any clues?
Here is the relevant code being used:
Code:
SetProcPermissions( 0xFFFFFFFF ); // should enable access to other threads
HANDLE hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS | TH32CS_SNAPTHREAD, 0);
THREADENTRY32 entry;
entry.dwSize = sizeof(THREADENTRY32);
BOOL more = Thread32First(hSnap, &entry);
while(more) {
GetThreadTimes( (HANDLE) entry.th32ThreadID, &creation, &exit, &kernel, &user);
more = Thread32Next(hSnap, &entry);
}
This snippet works fine on PPC devices, but for Smartphone, the GetThreadTimes() call results in an error code of 6 (ERROR_INVALID_HANDLE).
Any help is GREATLY appreciated. I'm trying to wrap up a project that may be trashed if I cannot get this data.
Thanks in advance,
Jay

File transfer over TCP sockets

I've been trying to get a simple file transfer between desktop app and phone app. The transfer works up to a point, when it simply ...stops dead.
The server(aka desktop client) enters the listening state, and the phone goes idle.
Anyone has any samples on transfers of large file (bigger than 1 MB)?
mcosmin222 said:
I've been trying to get a simple file transfer between desktop app and phone app. The transfer works up to a point, when it simply ...stops dead.
The server(aka desktop client) enters the listening state, and the phone goes idle.
Anyone has any samples on transfers of large file (bigger than 1 MB)?
Click to expand...
Click to collapse
Have you looked through GoodDayToDie's source code for the File Server? I wonder if he has anything in there that could make that work.
snickler said:
Have you looked through GoodDayToDie's source code for the File Server? I wonder if he has anything in there that could make that work.
Click to expand...
Click to collapse
lalz.
Completely forgot about that one xD
Meh he has it written in C++
Apparently, he didn't do anything that I didn't.
mcosmin222 said:
lalz.
Completely forgot about that one xD
Meh he has it written in C++
Click to expand...
Click to collapse
You can still utilize the transfer portion . I was thinking of seeing what I could do with sockets on the phone. I know it could come in handy somehow
snickler said:
You can still utilize the transfer portion . I was thinking of seeing what I could do with sockets on the phone. I know it could come in handy somehow
Click to expand...
Click to collapse
It's a pain in the ***.
It stops transfer at random points.
mcosmin222 said:
It's a pain in the ***.
It stops transfer at random points.
Click to expand...
Click to collapse
That doesn't surprise me at all for some reason.
Did you double-check your socket multithreading code?
I recently had problems with sockets and it turned out that I had the muti-threading thing wrong.
I think you shouldn't use only one connection and fail if it drops ...
ScRePt said:
Did you double-check your socket multithreading code?
I recently had problems with sockets and it turned out that I had the muti-threading thing wrong.
I think you shouldn't use only one connection and fail if it drops ...
Click to expand...
Click to collapse
What do you mean by socket multthreading code? You mean the use of async methods? or having the thread work on background, using the socket?
Take a look to the Tim Laverty's networking samples.
sensboston said:
Take a look to the Tim Laverty's networking samples.
Click to expand...
Click to collapse
That's what im doing (more or less)
@mcosmin222: The most common reason I saw for why that happened was the thread doing the transfer would crash. There's a lot of things that could cause such a crash, but because it's not the main thread or a UI thread, you don't see it. It just stops. In fact, even the debugger usually doesn't catch it (annoying as hell...)
There are a few common things that non-UI threads aren't allowed to do which you might be trying. For example, attempting to show a MessageBox on a non-UI thread will crash the thread (you can do it by adding a lambda or function to the dispatcher for the UI). In any case, feel free to use or adapt my code, or share yours here and if there's an obvious issue I'll point it out. Incidentally, you can set a larger buffer on the socket if you want the operation to complete without looping.
By the way, the only portion of my webserver that's written in C++ is the file I/O code, which I chose to do in C++ rather than .NET because the phone's stunted .NET framework makes it more difficult than I like to access arbitrary file paths. That code is all fairly clean wrappers around the Win32 calls; I suppose I could comment it more but it's very straightforward to read even if you aren't familiar with managed C++. The actual network code is entirely written in C# 4.5. You could actually simplify it a bit for a direct transfer app, too; I wrote it with a lot of multithreading in case I wanted to re-use the code somewhere that might be expected to have more than one client connecting at a time.
GoodDayToDie said:
@mcosmin222: The most common reason I saw for why that happened was the thread doing the transfer would crash. There's a lot of things that could cause such a crash, but because it's not the main thread or a UI thread, you don't see it. It just stops. In fact, even the debugger usually doesn't catch it (annoying as hell...)
There are a few common things that non-UI threads aren't allowed to do which you might be trying. For example, attempting to show a MessageBox on a non-UI thread will crash the thread (you can do it by adding a lambda or function to the dispatcher for the UI). In any case, feel free to use or adapt my code, or share yours here and if there's an obvious issue I'll point it out. Incidentally, you can set a larger buffer on the socket if you want the operation to complete without looping.
By the way, the only portion of my webserver that's written in C++ is the file I/O code, which I chose to do in C++ rather than .NET because the phone's stunted .NET framework makes it more difficult than I like to access arbitrary file paths. That code is all fairly clean wrappers around the Win32 calls; I suppose I could comment it more but it's very straightforward to read even if you aren't familiar with managed C++. The actual network code is entirely written in C# 4.5. You could actually simplify it a bit for a direct transfer app, too; I wrote it with a lot of multithreading in case I wanted to re-use the code somewhere that might be expected to have more than one client connecting at a time.
Click to expand...
Click to collapse
I am aware that some calls from background threads are not allowed, especially those that have to do with the UI thread.
This is the code for the server. It would seem this one is the problem, somewhere...I just can't see where...
I tried limiting the number of packages sent (that's what the timer is all about).
Code:
public class StateObject
{
// Client socket.
public Socket workSocket = null;
// Size of receive buffer.
public const int BufferSize = 1024;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
}
public class AsynchronousSocketListener
{
// Thread signal.
public static ManualResetEvent allDone = new ManualResetEvent(false);
public static string[] TransferStages = new string[] { "sendmetadataz-length", "sendmetadataz", "file-length", "file" };
public static int Index = -1;
public static List<string> FilePaths = new List<string>();
public static long CurrentStreamPosition = 0;
public static FileStream ifs;
static int pocketspersecond = 0;
static bool LimitExceded = false;
DispatcherTimer timer = new DispatcherTimer();
public static int CurrentArraySize = 0;
public static int FileIndex = 0;
public AsynchronousSocketListener()
{
timer.Interval = TimeSpan.FromSeconds(1);
timer.Tick += timer_Tick;
}
void timer_Tick(object sender, EventArgs e)
{
LimitExceded = false;
}
public static void StartListening()
{
// Data buffer for incoming data.
byte[] bytes = new Byte[StateObject.BufferSize];
// Establish the local endpoint for the socket.
// Note: remember to keep the portnumber updated if you change
// it on here, or on the client
IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Any, 13001);
// Create a TCP/IP socket.
Socket listener = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
// Bind the socket to the local endpoint and listen for incoming connections.
try
{
listener.Bind(localEndPoint);
listener.Listen(10);
while (true)
{
// Set the event to nonsignaled state.
allDone.Reset();
// Start an asynchronous socket to listen for connections.
Console.WriteLine("Waiting for a connection...");
listener.BeginAccept(
new AsyncCallback(AcceptCallback),
listener);
// Wait until a connection is made before continuing.
allDone.WaitOne();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
public static void AcceptCallback(IAsyncResult ar)
{
// Signal the main thread to continue.
allDone.Set();
// Get the socket that handles the client request.
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
// Create the state object.
StateObject state = new StateObject();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
public static void ReadCallback(IAsyncResult ar)
{
String content = String.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.UTF8.GetString(
state.buffer, 0, bytesRead));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1)
{
// All the data has been read from the
// client. Display it on the console.
Console.WriteLine("Read {0} bytes from socket. \n Data : {1}",
content.Length, content);
// Respond to the client
Send(handler, content);
}
else
{
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
}
}
public static void Send(Socket handler, String data)
{
//handler.SendBufferSize = File.ReadAllBytes(@"D:\MUZICA\Activ - Visez.mp3").Length;
// handler.BeginSendFile(@"D:\MUZICA\Activ - Visez.mp3", new AsyncCallback(SendCallback), handler);
#region cotobatura
data = data.Replace("<EOF>", "");
if (data.Contains("sendmetadataz") && data.Contains("length")==false)
{
data = MainWindow.DataContextModel.Files.ElementAt(FileIndex).ToString()+"<EOF>";
byte[] byteData = Encoding.UTF8.GetBytes(data);
// Begin sending the data to the remote device.
handler.BeginSend(byteData, 0, byteData.Length, 0,
new AsyncCallback(SendCallback), handler);
}
else if (data.Contains("sendmetadataz-length"))
{
Index++;
if (Index >= MainWindow.DataContextModel.Files.Count)
{
//FileIndex++;
data = "TransfersComplete<EOF>";
}
data = Encoding.UTF8.GetByteCount((MainWindow.DataContextModel.Files.ElementAt(FileIndex).ToString() + "<EOF>").ToString()).ToString();
byte[] MetaDataLength = Encoding.UTF8.GetBytes(data);
handler.SendBufferSize = MetaDataLength.Length;
handler.BeginSend(MetaDataLength, 0, MetaDataLength.Length, 0, new AsyncCallback(SendCallback), handler);
}
else if (data.Contains("file-length"))
{
ifs = File.Open(MainWindow.DataContextModel.Files.ElementAt(FileIndex).Location, FileMode.Open);
byte[] gugu = Encoding.UTF8.GetBytes(ifs.Length.ToString());
handler.SendBufferSize = gugu.Length;
handler.BeginSend(gugu, 0, gugu.Length, 0, new AsyncCallback(SendCallback), handler);
}
else if (data.Contains("file") && data.Contains("length") == false)
{
//byte[] filedata = File.ReadAllBytes(MainWindow.DataContextModel.Files.ElementAt(FileIndex).Location);
//handler.BeginSend(filedata, 0, filedata.Length, 0,
//new AsyncCallback(SendCallback), handler);
byte[] filedata = new byte[150];
for (int i = 0; i < 150; i++)
{
if (CurrentStreamPosition < ifs.Length)
{
filedata[i] = (byte)ifs.ReadByte();
CurrentStreamPosition++;
CurrentArraySize++;
}
else
{
Array.Resize(ref filedata, CurrentArraySize);
break;
}
CurrentArraySize = 0;
}
// if (pocketspersecond == 25) LimitExceded = true;
//Thread.Sleep(1000);
handler.BeginSend(filedata, 0, filedata.Length, 0, new AsyncCallback(SendCallback), handler);
}
//handler.BeginSendFile(MainWindow.DataContextModel.Files.ElementAt(FileIndex).Location, filedata, null, TransmitFileOptions.ReuseSocket, new AsyncCallback(SendCallback), handler );
// What we want to send back in this application is a game move based on what
// has been received. So we call Play on the GameLogic to give us a move to send back
// data = GameLogic.Play(data);
// Convert the string data to byte data using ASCII encoding.
//byte[] byteData = Encoding.UTF8.GetBytes(data);
// Begin sending the data to the remote device.
//handler.BeginSend(byteData, 0, byteData.Length, 0,
// new AsyncCallback(SendCallback), handler);
#endregion
}
public static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket handler = (Socket)ar.AsyncState;
// Complete sending the data to the remote device.
int bytesSent = handler.EndSend(ar);
Console.WriteLine("Sent {0} bytes to client.", bytesSent);
handler.Shutdown(SocketShutdown.Both);
handler.Close();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
}
This is basically modified from the tick tak toe over sockets sample from MSDN.
The only possible call that would affect the UI is the call to the Console, but the code works fine for a while, after it just crashes.
I tried running the whole thing synchronously on the UI thread, the result appears to be the same.
In the Send method, the first 3 stages work (file-legth, metadata, metadata-length) and a few steps in the file stage (which actually sends the file).
AT some point, I assumed the thread was guilty somehow, but I just can't prove it. Running the thing directly on UI thread does not seem to change anything.
If the async method finishes and the socket gets disposed, the thread would "die".
PS: the entire thing is hosted by a WPF application.
Hmm... OK, there are several bugs here. I'm not sure which, if any, are responsible for the problem. I'd be tempted to overuse try-catch-log (for example, on the Send() function) and debug-print statements, but here are some things I can see that could cause a crash or other unexpected failure:
There is no guarantee that "ifs" is instantiated before use. If you for some reason skip the file-length step, the file step will crash with a null pointer exception.
The entire send function is hugely thread-unsafe. For example, if a second request arrives before you're done servicing the first one (which is entirely possible due to where the event gets signaled) then the values of "ifs" and "CurrentStreamPosition" and so on will be unpredictable at any given time. Since CurrentStreamPosition seems to be monotonically increasing, that's probably not going to cause an out-of-bounds exception, but it could cause you to enter a state where the test "if (CurrentStreamPosition < ifs.Length)" always fails.
The line "data = "TransfersComplete<EOF>";" never does anything; the next line (immediately following it) overwrites that variable. If you cared about that string, too bad.
FileIndex never changes; I hope you're only ever sending one file here...
You don't actually check that the number of bytes sent is the number you meant to send (admittedly, it *should* be, but there are cases where it won't be).
The last 150-byte chunk of every file transfer is truncated to the first byte. This is because "CurrentArraySize" is reset to 0 on every iteration of the byte-read loop (why use a byte-read loop?) so whenever "CurrentStreamPosition < ifs.Length" tests false, the "filedata" array will be resized to one byte (or zero if the file is an exact multiple of 150 bytes, which presumeably be correct).
There are probably more, but that's what jumped out at me (well, and some technically correct stylistic issues, like the "... == false" test). Given that your protocol seems to rely on end-of-message flags, I'm guessing that your problem is that since the last part of the file is almost always truncated, that marker is never getting sent. This probably leads to the client concluding that the server will be sending it more data, which it does by sending another "file" request. The server attempts to respond and immedately hits the CurrentStreamPosition < ifs.Length check, fails, goes to the else case, and tries to send a 1-byte packet containing a NULL byte.
Incidentally, does your file transfer protocol really require that the client request each 150-byte chunk one at a time, using a new TCP connection each time? That's... awfully inefficient.
GoodDayToDie said:
Hmm... OK, there are several bugs here. I'm not sure which, if any, are responsible for the problem. I'd be tempted to overuse try-catch-log (for example, on the Send() function) and debug-print statements, but here are some things I can see that could cause a crash or other unexpected failure:
There is no guarantee that "ifs" is instantiated before use. If you for some reason skip the file-length step, the file step will crash with a null pointer exception.
The entire send function is hugely thread-unsafe. For example, if a second request arrives before you're done servicing the first one (which is entirely possible due to where the event gets signaled) then the values of "ifs" and "CurrentStreamPosition" and so on will be unpredictable at any given time. Since CurrentStreamPosition seems to be monotonically increasing, that's probably not going to cause an out-of-bounds exception, but it could cause you to enter a state where the test "if (CurrentStreamPosition < ifs.Length)" always fails.
The line "data = "TransfersComplete<EOF>";" never does anything; the next line (immediately following it) overwrites that variable. If you cared about that string, too bad.
FileIndex never changes; I hope you're only ever sending one file here...
You don't actually check that the number of bytes sent is the number you meant to send (admittedly, it *should* be, but there are cases where it won't be).
The last 150-byte chunk of every file transfer is truncated to the first byte. This is because "CurrentArraySize" is reset to 0 on every iteration of the byte-read loop (why use a byte-read loop?) so whenever "CurrentStreamPosition < ifs.Length" tests false, the "filedata" array will be resized to one byte (or zero if the file is an exact multiple of 150 bytes, which presumeably be correct).
There are probably more, but that's what jumped out at me (well, and some technically correct stylistic issues, like the "... == false" test). Given that your protocol seems to rely on end-of-message flags, I'm guessing that your problem is that since the last part of the file is almost always truncated, that marker is never getting sent. This probably leads to the client concluding that the server will be sending it more data, which it does by sending another "file" request. The server attempts to respond and immedately hits the CurrentStreamPosition < ifs.Length check, fails, goes to the else case, and tries to send a 1-byte packet containing a NULL byte.
Incidentally, does your file transfer protocol really require that the client request each 150-byte chunk one at a time, using a new TCP connection each time? That's... awfully inefficient.
Click to expand...
Click to collapse
I know it is inefficient, but I'm rather new to sockets. I just want it to get working in a "beta stage" then ill optimize it (hance the FileIndex never increasing, the blatant lack of try-catch blocks).
On the client side, once the bytes in the buffer are processed, the server gets another send that to send the following 150 bytes (i use 150 just for the lulz).
So basically, the workfow is as follows:
ask metadata length >server gives the length >client adjusts buffer>ask metadata
ask metdata >server gives metdata>client processes the data>asks file length
ask file length>server gives file length>client adjusts a huge array of bytes in which the file will reside (i know this is horribly inefficient, but at some point i will write directly to a file stream)>asks for the first 150 bytes in the file.
server gets the request, sends 150 bytes to client>client copies the 150 bytes in the array created earlier, the asks for the next 150.
I am using 150 just to make sure the data never splits in more than one buffer.
When the file transfer occurs, a different message is used to signal the end of transfer. Client side counts the bytes it gets, and when it is equal to the file length, it no longer asks 150 bytes.
The whole thing seems to be safe from crashing until it gets to the part where it sends the file. I am aware that in the code i gave you there's some file streams not getting closed, but i've fixed that and the problem still occurs.
Since The debugger won't help me at all, I decided to use a WCF service instead.
mcosmin222 said:
What do you mean by socket multthreading code? You mean the use of async methods? or having the thread work on background, using the socket?
Click to expand...
Click to collapse
I mean worker threads not async.You will always have to have a thread in the background to "accept". once you accept you "read" in a new thread and the parent thread "accepts" again. Accept will freeze the thread.
On the other side, you simply "connect" and "write" in the same thread.
Read and Write is done in a loop via pre-defined buffers syncronously.
But if you want the server to give a response, the above flow is the other way around, and it is then when things get complicated. (server needs to "connect" and client needs to "accept" over a different set of ports and different threads)
Probably if you want to have reliable connection you will need the server to come back with a response "give me more" or sth.
So, trying to assist, it was my guess that drops or stalls could be because the above flow is not implemented properly.
Edit Oh ho, missed a whole new page so I am sorry if the reply is irrelevant now.
I would suggest you use the sync methods of sockets and not callbacks because is super easier to debug. ThreadPool.QueueSth (ctr + space I dont remember how it's called is your friend to handle threads yourself.
And try to separate pure socket handling from domain handling (lengths, metadata, etc). Send some bytes back and forth, clean-up and then move to domain specific things!
Moving the line that resets CurrentArraySize to outside of the for loop may well sove your problem. I'd try that first.
Optimization involves, among other things, removing try blocks. Unoptimized code, when you're trying to just make thigns work, ought to be full of them.
Don't forget that exceptions will not bubble up the call stack across threads. In addition to threads you create yourself, any async callback will happen on a different thread than the one that called the async function. If an uncaught exception occurs, the thread will die. If enough threads die, the program may crash (or at least hang) due to threadpool exhaustion.
GoodDayToDie said:
Moving the line that resets CurrentArraySize to outside of the for loop may well sove your problem. I'd try that first.
Optimization involves, among other things, removing try blocks. Unoptimized code, when you're trying to just make thigns work, ought to be full of them.
Don't forget that exceptions will not bubble up the call stack across threads. In addition to threads you create yourself, any async callback will happen on a different thread than the one that called the async function. If an uncaught exception occurs, the thread will die. If enough threads die, the program may crash (or at least hang) due to threadpool exhaustion.
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Click to collapse
I avoid try-catch in unoptimized code to see where actual exceptions occur (sometime the debugger doesn't break on exception).
Nop still not working.
The thread still appears to be crashing, even wrapped with try catch.
Do you at least know *which* function it's crashing in? Try putting a breakpoint on each function header and then, when one of them is hit, step through the execution until the thread dies. Work backward from there to find the problem.
GoodDayToDie said:
Do you at least know *which* function it's crashing in? Try putting a breakpoint on each function header and then, when one of them is hit, step through the execution until the thread dies. Work backward from there to find the problem.
Click to expand...
Click to collapse
The send function (the one with the case switch) appears to be crashing.
It executes the function then enters the listening stage (does not execute the callback).

[Q] RS232 serial signal input via 3.5mm audio port of android smartphone

Hi and first thank you for reading my question!
I have a device, which gives me an output of essentially just a RS232 serial signal (1200 baud, 8 databits, no parity bits, one stop bit). This output comes in to my android phone via the 3.5mm audio jack.
I want to store every data bit into a variable, display or calculate something and when the next bits come in, it should override the variable.
I know exactly what to do with it after I thave the databits in variables but I have no idea on how to do the basic input / stream / read from audio jack thing...
More informations about my signal The payload is transmitted in 9 byte packets:
Code:
1: command byte as ASCII character ('I','A','S','L','R','C' or ' ')
2-6: time in ASCII chars (2:34:56)
7: checksum (64 + sum of time digits)
8: CR (carriage return, ASCII code 0x0D)
9: LF (line feed, ASCII code 0x0A)
I also think I have to store the input into a buffer and then read the signals from the buffer... But how do I write serial input from audio jack into a buffer?
Maybe something like this will work:
Code:
try
{
int N = AudioRecord.getMinBufferSize(8000,AudioFormat.CHANNEL_IN_MONO,AudioFormat.ENCODING_PCM_16BIT);
recorder = new AudioRecord(AudioSource.MIC, 1200, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, N*10);
track = new AudioTrack(AudioManager.STREAM_MUSIC, 1200,
AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, N*10, AudioTrack.MODE_STREAM);
recorder.startRecording();
track.play();
/*
* Loops until something outside of this thread stops it.
* Reads the data from the recorder and writes it to the audio track for playback.
*/
while(!stopped)
{
Log.i("Map", "Writing new data to buffer");
short[] buffer = buffers[ix++ % buffers.length];
N = recorder.read(buffer,0,buffer.length);
track.write(buffer, 0, buffer.length);
}
}
catch(Throwable x)
{
Log.w("Audio", "Error reading voice audio", x);
}
/*
* Frees the thread's resources after the loop completes so that it can be run again
*/
finally
{
recorder.stop();
recorder.release();
track.stop();
track.release();
}
}
Please help me, thank you!

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