Serial Communication in Windows. Environment: Source code. This article is meant to give you a jump start on doing serial communication in Windows (NT family). The article will provide a class called CSerial. Comm. Helper that you can use directly to do serial communication in your application. The class that is provided here with this article does uses overlapped IO. You do not need to know much about serial communication or overlapped IO for this article. However, you need to know some about the synchronization objects such as Events and some Windows APIs like Wait. For. Single. Object and Wait. For. Multiple. Object, and so forth. Also, some basic understanding of Windows threads is required—such as thread creation and termination. Introduction. In order for your computer to do serial communication, the computer has to have a serial port. Most computers have at least one serial port, also known as a COM port (communication port), and are generally called COM1, COM2, and so on. Then there are the device drivers for the serial ports. If you think it over, all that you need to do in serial communication is either send data or receive data. In other words, you are doing input/output (IO) to the serial port. The same IO is done with disk- based files. Hence it is no surprise that the APIs for reading and writing to a file apply to serial ports as well. When you send data to the serial port, it's in terms of bytes but when it leaves the serial port it is in the form of bits. Similarly, when the data arrives at the serial port, it's in bit format and when you get data you get it in bytes. Without any further discussion, let's get started. Opening the COM Port. The first and the foremost step in doing a serial communication is to open the desired port. Let's say you have your device hooked to COM1; you can open the COM port using the following API. HANDLE m. We want to open the file (the COM port) in an overlapped fashion—that's why the sixth parameter is FILE. We will get into the details of overlapped IO a bit later. As you must have guessed from the name, the Create. File() API can be used to create a file (disk- based); it also can be used to open an existing file. To Windows, a serial port or a disk- based file both are IO devices. So, to open an existing file (serial port), all we need to know the name of the device (COM1) and pass the creation flags as OPEN. Get certified for Microsoft technology and products. Explore our online developer & computer courses and exams, and take your career to a new level. Visual Studio 2012 continues to be the hands-down leader in the applications development space. Learn about some of the major new features in Visual Studio 2012. Indusoft Web Studio, SCADA Software & Projects. FF-Automation is exclusive distributor of Indusoft Web Studio in Finland but we are doing SCADA& RTU projects all. I prefer to use the Visual Studio environment to write and test code for the Arduino. For most users, the Visual Studio Plugin might be the. This article will show you how to make your own Serial Port Communication software interface (which is basically a Windows Form Application) using Microsoft Visual. Visual Micro: Develop Arduino programs with Microsoft Visual Studio or Atmel Studio. Download Visual Micro. Based on Microsoft Visual Studio - The Community Edition. Fact: You need Visual Studio 2015 Update 1 to build apps for Windows 10 IoT-Core Build 10586 (as released publically on 3rd December 2015). However, if the system could not open the COM port, it would return INVALID. And you can get the reason by calling Get. Last. Error(). One of the common errors when opening a COM port is that the COM port is already opened by some other application; in that case, you would get ERROR. Similarly, if you mistakenly opened a COM port that does not exist , you would get ERROR. For example, let's say you want to send . When you want to send the data across the serial port, you need to write to the serial port just as you would write to a file. Timepiece.com is not affiliated with any website that sells fake or replica watches.You would use following API: i. Ret = Write. File (m. So, you need to read the data. Again, you would use the following API: ab. Ret = : :Read. File(m. We will get to all this later. All this sounds very simple. Right? Now, let's start digging into issues. Issues with Serial Communication. Just now I said that, in response to your . But the problem here is that you don't know when the device is going to respond. Or, will it ever respond? When should you start to read from the port? One option is that as soon as you made the call to Write. File, you make a call to Read. File. If no data is there, you need to make a read call again, later on. This leads to what is called polling. You keep polling the port for data. This model does not really seem to be a good one. It would be nice if somehow the system notified you when data has arrived and only then would you make a call to Read. File. This is an event- driven approach and fits well into Windows programming. And the good news is that such a model is possible.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
November 2016
Categories |