Wpf Serial Port
SerialComm Monitor is a serial communication application based on SerialPort class, built in C# WPF with MVVM design pattern to send (write) or receive (read) data. Initializes a new instance of the SerialPort class using the specified port name, baud rate, parity bit, data. Use this class to control a serial port file resource. Oct 17, 2010 When using the SerialPort.GetPortNames() method, you are querying the current computer for a list of valid serial port names. For example, you can use this.
This article will guide you through the process of robot or embedded system control using a WPF application. There are mainly two types of Robotics but sometimes a hybrid model becomes a necessity.
Robotics control can be done using a controller but then again, the cost factor is also relevant. You won't feel like spending hundreds of bucks for your control of various robots. It's always beneficial when you have a software model for this purpose. The following hardware is required:. An Arduino developer board (I have used an Arduino Leonardo). Light Emitting Diode (LED).
The following software is required:. Arduino IDE. Visual Studio Arduino An Arduino is a developer board built around the Atmel AVR microcontrllers. They are used in embedded systems and robotics applications, this open-source hardware is one of the best developer boards to design your embedded systems.
Figure 1: A layout of an Arduino Leonardo developer board. Picture credit: Let's begin with the Arduino part first. We will be turning on and off an LED and using a WPF app. First let us see the circuit diagram. We will connect the LED to pin number 13. The LED's longer pin will be in the pin number 13 whereas the shorter in the GND pin.
Figure 2: Circuit diagram. The LED is connected to the pin 13 and GND. Our next course of action is to program the Arduino. First connect the Arduino to the USB. For drivers and the IDE, visit.
Now after connecting the Arduino board to your PC, go to Tools, then port to select the port where your Arduino is connected. Also select your developer board by clicking Tools and selecting Board. The following Figure 3 shows the screenshot of the IDE where you need to select. Figure 3: Screenshot of the IDE where you need to select the port and the board. After selecting the board and the port, we will go to the programming. pinMode(13,OUTPUT); Here 13 is the pin number whereas the output is used to configure it. You can also use other pins but since we have connected the LED to pin number 13, we have used 13.
The next part is where you need to define the Baud Rate. The Baud Rate in this case will be 9600. You can use other values as well but in that case the value that you use here must match the one you use in your WPF app. Serial.Begin(9600) is used to start the Serial port communication. These are the parts under the setup function. In void loop, the code that needs to be executed repeatedly is inserted out there.
Since we are using Serial port communication, our first course of action is to accept a value through the communication channel. In order to do that, we will first check whether the link is available with the following line of code. Now let us browse to MainWindow.xaml.cs and begin the real code. As already mentioned before, we will use the SerialPort class so we need to add this first.
From this code, it is not clear what delay in serial communication is required and why, but the implementation of the delay is wrong anyway. You use spin wait which should be avoided by any means.
Spin wait use 100% of the CPU core without any purposes. All wait methods should be based on thread methods. 1) To wait unconditionally for certain amount of time, use System.Threading.Thread.Sleep. 2) If you need to wait until certain condition, always use System.Threading.EventWaitHandle.WaitOne (with timeout or not). In both cases, the thread is switched off by OS and never scheduled back to execution until waken up by OS. It will be waken up by expiration of time, or the following methods called from another thread: Thread.Abort or System.Threading.EventWaitHandle.Set (second one to be used if a thread is in the wait state at the call to System.Threading.EventWaitHandle.WaitOne on the same instance of EventWaitHandle.
Do I even have to mention that your serial communication should be done in a separate thread, not UI thread? This is absolutely important.
Now, it looks like by some reason you need to wait until the UI is fully updated with new data. First, think again, do you really need it? If you insist on that (yes, it can be a good solution by several reasongs), it can be achieved a bit simpler. You can use Dispatcher.Invoke instead of Dispatcher.BeginInvoke. First method delays the thread calling Invoke be the end of the actual call of the delegate, while BeginInvoke will return as soon as delegate instance and the data used for the call are placed to the invocation queue of the UI thread. For more detail on invocation, see also my past Answers: EDIT You need certainly to put port communications in a separate thread, good point.
The main design idea is: as you do the communications during all the life time of your application, it can be created from the very beginning and kept running. It can be synchronized using thread synchronization primitives. Best way to create such a thread is to use my thread wrapper:. Other options include using a thread pool (you can create a similar wrapper) or BackgroundWorker (which I would rather recommend for temporary tasks. A good way to organize synchronized communication is using a generic blocking queue. See my Tips/Tricks article and the 'alternative' answer (not really alternative, it's just the advice to use the similar class available in v.4.0):.
At to WPF, it is important to know that you cannot call any UI elements from non-UI thread, so you need to use inter-thread invocation. For WPF, you should use Dispatcher.Invoke or Dispatcher.BeginInvoke. See my other Answers for the explanation of how it works and the samples:. Thanks but as I said I am a very beginner in WPF and I code more like C than C# WPF. I still cannot grasp the idea of the separate thread. My function needs to do the following - loop several times fill TX buffer send TX buffer to serial port write TX buffer to textblock wait until there are 11 characters in the RX buffer (or timeout) read RXbuffer from serial port write RX buffer to textblock check if RX data is good or not wait 100ms repeat loop I dont need my application to be active while running the above function but I need it to update the textblock with the serial TX/RX data.
If clicks create new thread, this is waste of performance in most cases. You better create a thread from the very beginning but keep it in wait state.
In my references, locate the use of EventThreadHandle or see my article on blocking queue. In short, you prepare a task for a thread and wake it up. The button can be used for waking up, but not for creating and starting the thread. This is in some of my referenced text already. Also, serial communication is a thread sync mechanism itself. If you need to read from a serial port, you call a read method and get blocked.
(That's why you need thread). By when you are at the blocking call 'read', the thread is again sleeping and waiting, which is good, no CPU time is wasted. This I actually put all my basic directions, you only need to see how to apply them. If you study it, get basic understanding and later will need to ask more concrete question, I will try to answer. After testing further I managed to locate the performance problem I mentioned in the original question.
It has all to do with the TextBlock. I replaced it with a TextBox and now my application works just fine even without Threads.
Ofcourse I will be studying Threads and try to implement them in my application but in the meantime it is working as intended. So for others who might experience the same timing problem, just use a TextBox and AppendText instead of TextBlock.Inlines.Add. The latter works fine for few lines but becomes very very slow when you have many lines.
That was causing all my timing problems. When answering a question please:.
C# Serial
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Ps/2 Port
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C# Wpf Serial Port
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