For a school project i'm working with Unity. Im making a "game" where you need to connect devices with cables.
So I have a object called "device" with a script "deviceController". The Device object has a List containing other objects with a script called "portController".
Currently im trying to set a bool(anyCablesConnected) to true in the deviceController, if there are any cables in a port to a device and if there are no cables connected to the device set the bool to false. The portController also has a bool called "Occupied".
Only I have no idea how to do this. Do I use a foreach loop or something like that ?
foreach(port in device){
// IF A PORT FROM A DEVICE IS OCCUPIED, SET ANYCABLESCONNECTED TO TRUE
if (occupied == true){
anyCablesConnected = true;
} else {
anyCablesConnected = false;
}
}
Something like this ? I haven't really worked with foreach loops. But I hope you guys can help me !
If I understand you correctly, anyCablesConnected should be true iff at least one cable is connected. The logic for that is:
anyCablesConnected = false;
foreach (var port in device)
{
// IF A PORT FROM A DEVICE IS OCCUPIED, SET ANYCABLESCONNECTED TO TRUE
if (port.GetComponent<portController>().occupied)
{
anyCablesConnected = true;
// No need to continue looping, we have already found a cable
break;
}
}
Or you can use LINQ for a more compact solution:
anyCablesConnected = device.Any(x => x.GetComponent<portController>().occupied);
Note that I have made some assumptions as to how your occupied flag is accessed!
Alright, while writing the answer seems to have popped up. But to spare me deleting everything while giving you some context on how foreach works.
A list containing strings; List<string>, would be written like this:
List<string> listWithStrings = new List<string>();
listWithStrings.Add("Hello");
listWithStrings.Add("World");
and looped through with a foreach:
foreach (string stringInList in listWithStrings) {
Debug.Log(stringInList);
// The first loop stringInList will be "Hello",
// the second loop it will be "World"
}
Which is pretty much the same as a standard for-loop would be:
for (int i = 0; i < listWithStrings.Count; i++) {
Debug.Log(listWithStrings[i]);
}
But a lot easier and cleaner.
Related
For a project, I have to communicate with a Raspberry Pi Zero from a UWP-APP via TCP. Because both, the Raspberry and the computer with the interface, have got a private IP, I have to use a server to forward messages from one client to the other one. This part already works but now my problem is that I have to implement video streaming from the Raspberry to the UWP-APP.
Because my partner is in charge of creating and designing the UWP-APP, I have made myself a little Test-Interface with WindowsForms. I have tried several techniques like Netcat the video output over the server to the client or direct TCP-streaming with raspivid, but the best solution so far is the one I found in this project here. But instead of using the Eneter.Messaging-library I use my own class for communication with TcpClients.
I use mono to run my C# script on the Raspberry and the code to stream the Video looks like this:
while (true)
{
//Wait with streaming until the Interface is connected
while (!RemoteDeviceConnected || VideoStreamPaused)
{
Thread.Sleep(500);
}
//Check if Raspivid-Process is already running
if(!Array.Exists(Process.GetProcesses(), p => p.ProcessName.Contains("raspivid")))
raspivid.Start();
Thread.Sleep(2000);
VideoData = new byte[VideoDataLength];
try
{
while (await raspivid.StandardOutput.BaseStream.ReadAsync(VideoData, 0, VideoDataLength) != -1 && !VideoChannelToken.IsCancellationRequested && RemoteDeviceConnected && !VideoStreamPaused)
{
// Send captured data to connected clients.
VideoConnection.SendByteArray(VideoData, VideoDataLength);
}
raspivid.Kill();
Console.WriteLine("Raspivid killed");
}
catch(ObjectDisposedException)
{
}
}
Basically, this method just reads the h264 data from the Standard-Output-Stream of the raspivid process in chunks and sends it to the server.
The next method runs on the server and just forwards the byte array to the connected interface-client.
while (RCVVideo[id].Connected)
{
await RCVVideo[id].stream.ReadAsync(VideoData, 0, VideoDataLength);
if (IFVideo[id] != null && IFVideo[id].Connected == true)
{
IFVideo[id].SendByteArray(VideoData, VideoDataLength);
}
}
SendByteArray() uses the NetworkStream.Write() Method.
On the interface, I write the received byte[] to a named pipe, to which the VLC-Control connects to:
while (VideoConnection.Connected)
{
await VideoConnection.stream.ReadAsync(VideoData, 0, VideoDataLength);
if(VideoPipe.IsConnected)
{
VideoPipe.Write(VideoData, 0, VideoDataLength);
}
}
Following code initializes the pipe-server:
// Open pipe that will be read by VLC.
VideoPipe = new NamedPipeServerStream(#"\raspipipe",
PipeDirection.Out, 1,
PipeTransmissionMode.Byte,
PipeOptions.WriteThrough, 0, 10000);
And for VLC:
LibVLC libVLC = new LibVLC();
videoView1.MediaPlayer = new MediaPlayer(libVLC);
videoView1.MediaPlayer.Play(new Media(libVLC, #"stream/h264://\\\.\pipe\raspipipe", FromType.FromLocation));
videoView1.MediaPlayer.EnableHardwareDecoding = true;
videoView1.MediaPlayer.FileCaching = 0;
videoView1.MediaPlayer.NetworkCaching = 300;
This works fine on the Windowsforms-App and I can get the delay down to 2 or 3 seconds (It should be better in the end but it is acceptable). But on the UWP-App I can't get it to work even after adding /LOCAL/ to the pipe name. It shows that the VLC-Control connects to the pipe, and I can see that data is written to the pipe but it doesn't display video.
So my question is:
How can I get this to work with the VLC-Control (LibVLCSharp) in UWP? Am I missing something fundamental?
Or is there even a better way to stream the video in this case?
I have researched a bit on the UWP-MediaPlayerElement to but I can't find a way to get my byte[] into it.
First of all, thank you for your quick responses and interesting ideas!
I took a look into Desktop Bridge but it is not really what I wanted, because my colleague has already put in a lot of effort to design the UWP-APP and my Windows-Form is just a botch to try things out.
But the thing that really worked for me was StreamMediaInput . I have no idea how I missed this before. This way I just passed my NetworkStream directly to the MediaPlayer without using a Named-Pipe.
LibVLC libVLC = new LibVLC();
videoView1.MediaPlayer = new MediaPlayer(libVLC);
Media streamMedia = new Media(libVLC, new StreamMediaInput(Client.Channels.VideoConnection.stream), ":demux=h264");
videoView1.MediaPlayer.EnableHardwareDecoding = true;
videoView1.MediaPlayer.FileCaching = 0;
videoView1.MediaPlayer.NetworkCaching = 500;
videoView1.MediaPlayer.Play(streamMedia);
This solution is now working for me both, in UWP and in Windows-Forms.
I am trying to figure out how to check if a webcam/video capture device is already being used by another application without actually activating it.
My current approach is to use the AForge.NET library and using the .IsRunning property of the VideoCaptureDevice object like this:
var videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
foreach (FilterInfo videoDevice in videoDevices)
{
VideoCaptureDevice camera new AForge.Video.DirectShow.VideoCaptureDevice(videoDevice.MonikerString);
Debug.Print(camera.IsRunning)
}
I guess the IsRunning property only works on VideoCaptureDevices that have been started using the library and I need lower-level DirectShow access to the device.
While there are many ways to use DirectShow in C#, I have been unable to find a way to check the state even using DirectShow in C++. Is there some magic I need to perform here?
Thanks
Tobias Timpe
I'm not entirely sure if this will be helpful to you, but I found your question because I wanted to write a custom app to control my busylight. This is very much 'Works On My Machine' certified - it's not an attempt to give a general answer. However, I figure it may help you, and possibly the next person who comes across this page while googling...
private static bool IsWebCamInUse()
{
using (var key = Registry.CurrentUser.OpenSubKey(#"SOFTWARE\Microsoft\Windows\CurrentVersion\CapabilityAccessManager\ConsentStore\webcam\NonPackaged"))
{
foreach (var subKeyName in key.GetSubKeyNames())
{
using (var subKey = key.OpenSubKey(subKeyName))
{
if (subKey.GetValueNames().Contains("LastUsedTimeStop"))
{
var endTime = subKey.GetValue("LastUsedTimeStop") is long ? (long) subKey.GetValue("LastUsedTimeStop") : -1;
if (endTime <= 0)
{
return true;
}
}
}
}
}
return false;
}
I'm attempting to write a C# library which looks at all available USB serial ports on a Raspberry Pi so that I can enumerate, identify and communicate with a set of Arduinos connected to the Pi via a USB hub.
I am able to make this work on my windows machine (several Arduinos connected to my desktop computer) and have even been able to make it work on my Pi however, I am struggling to understand how to generalize the fix.
If I attempt to run the program by itself on the Pi, I am able to open the serial port and send data however, I cannot receive anything from the Arduinos: I get timeout exceptions. I understand that Mono's implementation of SerialPort is limited and I must use SerialPort.ReadByte() instead of Readline() and the data received events (my solution is based on code from HowToSystemIOPorts). My Serial port enumeration is using a method outlined in another stack exchange response here.
My timeout is currently set to 4 seconds, which is several orders of magnitude longer than I expect to receive the message.
After a lot of googling, I came across mention of using minicom to initialize the serial port here, which to my surprise allowed me to receive data from the Arduino. The biggest drawback is that I need to initialize the port using minicom and leave the process opening each time I boot the Pi. I also can't seem to figure out how to make this work with multiple Arduinos.
Here is what I have tried so far:
Updated the Pi firmware and software to their latest versions
Attempted to use both an Arduino MEGA 2560 R3 and Arduino UNO
Changed the owner of the tty* ports (ttyACM0 and ttyUSB0 in this case) to both my user and group
Successfully configured the port via minicom, left the process running and start the program and read/wrote data. A manual process which only seems to work for one Arduino at a time
Successfully run the program in Windows without fault
Verified the Arduinos are recognized by the Pi running "dmesg | grep tty"
Here is what I hope to solve:
Automatic setup/initialization of the Arduino serial ports. Whether through a shell script run before the main program or within Mono code so that the code below can run as intended.
Here is my connection code:
public bool StartArduinoComms()
{
string[] ports = GetPortNames();
foreach (string port in ports)
{
mLogger.LogMessage(ProsthesisCore.Utility.Logger.LoggerChannels.Arduino, string.Format("Found serial port {0}", port));
}
bool foundCorrectArduino = false;
var idPacket = new ArduinoMessageBase();
idPacket.ID = ArduinoMessageValues.kIdentifyValue;
string jsonOutput = Newtonsoft.Json.JsonConvert.SerializeObject(idPacket);
foreach (string port in ports)
{
SerialPort serialPort = new SerialPort(port, kArduinoCommsBaudRate);
serialPort.Parity = Parity.None;
serialPort.DataBits = 8;
serialPort.StopBits = StopBits.One;
//Only check unopened ports
if (!serialPort.IsOpen)
{
serialPort.Open();
//Disable telemtry just incase
var toggle = new { ID = ArduinoMessageValues.kTelemetryEnableValue, EN = false };
string disableTelem = Newtonsoft.Json.JsonConvert.SerializeObject(toggle);
serialPort.Write(disableTelem);
//Discard any built up data
serialPort.DiscardInBuffer();
serialPort.Write(jsonOutput);
serialPort.ReadTimeout = kIDTimeoutMilliseconds;
string response = string.Empty;
for (int i = 0; i < kNumRetries; ++i)
{
try
{
//This is guaranteed to timeout if not configured through minicom
response = ReadLine(serialPort);
break;
}
//Catch case where the serial port is unavailable. MOve to next port
catch (TimeoutException)
{
continue;
}
}
if (!string.IsNullOrEmpty(response))
{
//Perform response validation
}
else
{
//Got no response
}
if (!foundCorrectArduino)
{
serialPort.Close();
}
}
}
return foundCorrectArduino;
}
/// <summary>
/// From https://stackoverflow.com/questions/434494/serial-port-rs232-in-mono-for-multiple-platforms
/// </summary>
/// <returns></returns>
private static string[] GetPortNames()
{
int p = (int)Environment.OSVersion.Platform;
List<string> serial_ports = new List<string>();
// Are we on Unix?
if (p == 4 || p == 128 || p == 6)
{
string[] ttys = System.IO.Directory.GetFiles("/dev/", "tty*");
foreach (string dev in ttys)
{
//Arduino MEGAs show up as ttyACM due to their different USB<->RS232 chips
if (dev.StartsWith("/dev/ttyS") || dev.StartsWith("/dev/ttyUSB") || dev.StartsWith("/dev/ttyACM"))
{
serial_ports.Add(dev);
}
}
}
else
{
serial_ports.AddRange(SerialPort.GetPortNames());
}
return serial_ports.ToArray();
}
Have a look at stty command. It will let you set/read teminal settings
http://linux.about.com/od/lna_guide/a/gdelna38t01.htm will give a rundown on it's use.
It would be easier to call out to than minicom, and the settings stay on the device.
I have done something like the same as you before.
I had to read and write data through USB Serial adapter, and didnt use minicom.
It may not be god code but i found that inorder to read the data I could create a new thread and have that check for data, my code include a lot of stuff but basicly i did this:
System.Threading.Thread newThread;
newThread = new System.Threading.Thread(this.check_get_data);
and the check_get_data method
public void check_get_data ()
{
byte tmpByte = 0;
while (m_objSerialPort.BytesToRead != 0) {
tmpByte = (byte)m_objSerialPort.ReadByte ();
DoSomethingWithByte(tmpByte);
Thread.Sleep(20);
}
}
this is currently running with two usbserials. dont know if it helps but hope you find your solution
I am new to C# and is currently using COSMOS to make a simple FileSystem for my OS class. Currently I'm trying to implement a "reformat" function that, when the word "reformat" is typed into the console, the OS (emulated via QEMU), partitions the disk. Currently this is my code:
public static void console()
{
while (true)
{
Console.WriteLine("Console: ");
String input = Console.ReadLine();
if (input == "exit")
{
Cosmos.Sys.Deboot.ShutDown();
}
else if (input == "cpumem")
{
Console.WriteLine(Cosmos.Kernel.CPU.AmountOfMemory.ToString());
}
else if (input == "restart")
{
Cosmos.Sys.Deboot.Reboot();
}
else if (input == "devices")
{
var devices = Cosmos.Sys.FileSystem.Disk.Devices.ToArray();
}
else if (input == "reformat")
{
try
{
Partition part = null;
for (int j = 0; j < Cosmos.Hardware.BlockDevice.Devices.Count; j++)
{
if (Cosmos.Hardware.BlockDevice.Devices[j] is Partition)
{
part = (Partition)Cosmos.Hardware.BlockDevice.Devices[j];
}
}
var fs = new Cosmos.Sys.FileSystem.FAT32.FAT32(part);
uint cluster = 100;
fs.Format("newCluster", cluster);
}
catch
{
//Do Something warn user.
}
}
}
}
Most important is this bit:
else if (input == "reformat")
{
try
{
Partition part = null;
for (int j = 0; j < Cosmos.Hardware.BlockDevice.Devices.Count; j++)
{
if (Cosmos.Hardware.BlockDevice.Devices[j] is Partition)
{
part = (Partition)Cosmos.Hardware.BlockDevice.Devices[j];
}
}
var fs = new Cosmos.Sys.FileSystem.FAT32.FAT32(part);
uint cluster = 100;
fs.Format("newCluster", cluster);
}
catch
{
//Do Something warn user.
}
}
Which is analogous to what is located here: http://cosmos-tutorials.webs.com/atafat.html
However, when I run it, I get this error:
I believe this is because I lack this line:
Cosmos.System.Filesystem.FileSystem.AddMapping("C", FATFS);
FATFileList = FATFS.GetRoot();
Located in the link above. Is there any other way to map? Or am I missing something completely? The COSMOS documentation doesn't really tell much, the source code is honestly confusing for a beginner like me as it has no comments whatsoever on how the functions work or what they do. I am using an older version of COSMOS (Milestone 4) as it's the only one that works for Visual Studio C# 2008. Newer versions run only in Visual Studio C# 2010.
Ah, I recognize this... had to debug a similar situation on a Cosmos project I'm working on myself (I'm using the VS2010-compatible Cosmos but the same situation might apply to older versions as well...)
This can happen if you try to call a method on a null object. Type 0x........, Method 0x........ is specifically mentioning the location in the compiled code where the call failed. "Not FOUND!" means that the method it is looking for cannot be found, presumably because you called it on a null reference.
I'm testing with VirtualBox myself, and found that if you're using a brand-new blank hard disk image, there will be no Partitions on it. Thus, the condition will never get satisfied, your Partition will never get set and then Cosmos will try to execute a method on the null Partition!
Look closely at how you set the Partition (it's initialized to null). For starters I would print a simple message each time the "if (block device is partition)" condition is satisfied... I would be willing to bet it will never print.
Hope this helps... I am still learning about Cosmos and custom kernels myself but fixing the null reference in my case solved my occurrence of the problem. If that's the problem, then the next step, of course, is figuring out why you're not getting any Partitions in the first place...
The rest of your code looks fine but I am not sure how you implemented the rest of your classes. Kernel debugging can be a nightmare, good luck to you!
I'm working on a mobile application (C#/WPF on a tablet PC) that prints to a bluetooth connected printer. Right now I just fire off a print job, and if the printer is not present the printer subsystem reports an error to the user. I'm not doing anything programatically with Bluetooth, just using PrintDialog().
I'd like to modify this process to detect the printer first - if it is not available, then I'll just store the document without printing. Is there a way in code for me to detect if the bluetooth device is connected/active/available?
If I look at the device in the Bluetooth panel under Control Panel, it doesn't seem to have any sort of status that reflects whether or not the device is available, so maybe this isn't possible.
I'm assuming the printer has already been setup and configured in Windows - all I need to do is detect if it is actually present at a given point in time.
Perhaps use the 32feet.NET library (of which I am the maintainer) and check if the printer is present before submitting the job. You'd need to know the Bluetooth address of the printer; can one get that from the system, or maybe you always know it.
Discovery on the MSFT Bluetooth stack always returns all known devices in amongst those in range :-( but we can use other means to detect the device's presence/absence. Perhaps using BluetoothDeviceInfo.GetServiceRecords in its BeginGetServiceRecords form. e.g. something like (not tested/compiled):
bool IsPresent(BluetoothAddress addr) // address from config somehow
{
BluetoothDeviceInfo bdi = new BluetoothDeviceInfo(addr);
if (bdi.Connected) {
return true;
}
Guid arbitraryClass = BluetoothService.Headset;
AsyncResult<bool> ourAr = new AsyncResult<bool>(); // Jeffrey Richter's impl
IAsyncResult ar = bdi.BeginGetService(arbitraryClass, IsPresent_GsrCallback, ourAr);
bool signalled = ourAr.AsyncWaitHandle.WaitOne(Timeout);
if (!signalled) {
return false; // Taken too long, so not in range
} else {
return ourAr.Result;
}
}
void IsPresent_GsrCallback(IAsyncResult ar)
{
AsyncResult<bool> ourAr = (AsyncResult<bool>)ar.AsyncState;
const bool IsInRange = true;
const bool completedSyncFalse = true;
try {
bdi.EndGetServiceResult(ar);
ourAr.SetAsCompleted(IsInRange, completedSyncFalse);
} catch {
// If this returns quickly, then it is in range and
// if slowly then out of range but caller will have
// moved on by then... So set true in both cases...
// TODO check what error codes we get here. SocketException(10108) iirc
ourAr.SetAsCompleted(IsInrange, completedSyncFalse);
}
}