Basic example of serial communication with Windows XP/win32 - windows

I am working with a peripheral device that needs to be communicated through serial. I can send it commands using HyperTerminal, but now I need to write programs that will let me do it without HyperTerminal. Can somebody point me to a website and/or show me a sample hello world program to get me started? I have searched through many sites which give me uncompilable/ancient VC6 code.

In order to interface with the serial port, you open a file with one of the special filenames "COM1" through "COM9". For serial ports with higher numbers, the special filename begins with \\?\, which in C/C++ code must be escaped as "\\\\?\\COM10", etc.
http://msdn.microsoft.com/en-us/library/ms810467.aspx has a really good tutorial on using the serial port. Note that you should use the Windows file I/O functions such as CreateFile(), ReadFile(), and WriteFile(). I'm not sure if it will work to use standard I/O functions such as fopen(), fread(), and fwrite().

Microsoft provides an article with sample code describing how to do this under Win32.

Boost:asio may be able to help as a serial device was added recently.
Fair warning though; the serial port documentation is light, presumably since it's quite new (it was added in asio 1.1.1 which was included in boost 1.36).
But working your way through asio is, IMHO, a better solution than using the raw Win32 API. Why? It'll be easier to read and maintain (it's a higher level API) and it'll be cross platform (except where you need to specify the OS-specific device name).
The Boost - Users and asio.user mailing lists are quite active and friendly and ought to be able to help you out if you get stuck.

If using .NET 2.0 see System.IO.Ports and this article should be helpful. If direct Win32, then Adam's answer is best.

I believe you will find plenty of sample code for C# as well if you find VC6 too ancient. I think there are also a bunch of "free" serial/COM port wrappers but I just wrote my own when I wrote an RS232 device controller piece of software.
google C# and serial port or rs232
I got these:
http://msdn.microsoft.com/en-us/library/system.io.ports.serialport.aspx
http://msmvps.com/blogs/coad/archive/2005/03/23/SerialPort-_2800_RS_2D00_232-Serial-COM-Port_2900_-in-C_2300_-.NET.aspx
You should have no problem finding suitable code with a google search.

Related

Good GUI library for program that connects to a microcontroller?

I'm trying to find a good GUI library I could use to create a program on the computer that connects to a microcontroller by USB. I've never done any GUI work before but I have done a lot of webpage design/tools. We are going to program the microcontroller with C but I don't think the GUI will need to be C. It needs to work on Windows, so probably compile on Windows too. I've also never done any USB transmission but I'm hoping to take it one step at a time.
Right now I'm looking at using GTK but it needs a bunch of other things to download with it. I'm also going to look at QT and someone else suggested making a Windows Forms Application. There's a lot of options out there so I'm having trouble figuring it out.
As for my requirement, it just needs to be a very simple GUI that has a few control buttons, a display area (info from microcontroller), a notification area (basically error messages go here), and maybe a graph. I've included a prototype GUI help give you an idea of what I'm doing.
Edit: It needs to run and compile on Windows. We don't really have a budget for it, free open source is preferred. I don't need something elaborate and fancy, I just want to get it done as fast as possible.
We are using a TTL-232R cable, UART interface. I know nothing about USB transmission, school has crushed me.
From what you've specified, I would set base-camp up at Java.
Java in Eclipse to write the code.
Java Swing libraries (helped by the WindowBuilder plugin for Eclipse) to "draw" the GUI. It is very easy to create "Windowsy" GUIs using these.
JFreeGraph libaries to allow you to create graphs very easily, again from within Eclipse.
RXTX library for "virtual COM port" serial communication within Java (it doesn't sound like you're using proper USB, but just RS232 with a USB adapter).
Your created GUI would run on any machine with Java installed, which is not a big ask for the end user. You can even create a Windows executable/installer from the resulting Java files if you wanted it to be a (apparently) native Windows application.
And - bonus - all the tools mentioned are free as a bird.
It will kind of depend on what kind of compiler, IDE, etc you will settle on. If you are going to windows cold, and
money is an issue, then open source is always a good thing to look at. I have enjoyed using eclipse and Code::Blocks IDEs. For C/C++, I use minGW. In terms of GUI plug-ins, HERE are some conversation with GUI recommendations specifically for use with Code::Blocks.
If money is not an issue, I have use National Instruments LabWindows/CVI full dev kit forever. It is one of the easiest ANSI C compilers/IDE I have ever used. It is only ANSI C, but has extensions to make using instrumentation easy. I have written a little USB stuff (not much), sockets, instrumentation, and many GUI apps.
Please comment what tools you currently prefer, I may have other suggestions.
Lazarus CodeTyphon has cross platform native compiler with GUI working on every supported platform. It supports 8 OS-CPU host layers (Win32, Win64, Linux32, Linux64, FreeBSD32, FreeBSD64, Solaris32 and Solaris64), and 25+ OS-CPU target layers. It also incorporates many graphical widgets and SCADA like behaviour with PascalSCADA and other components. There are wrappers for LibUSB.
I would use Microsoft Visual Studio to develop the GUI. They offer a free version called Express. I would use the C# language but MSVS supports other languages as well so just choose whichever you're most comfortable with. The best thing about MSVS is that there are millions of developers out there, which means that you will be able to search for and find lots of examples for how to use an RS-232 COM port or USB interface. I'm guessing that you'll be able to find GUI objects for graphing and other objects as well. (The basic stuff like buttons and edit boxes is all built into MSVS.)
BTW, you need to sort out whether you're using an RS-232 COM port or a USB interface. They're both serial interfaces but they're not the same thing. Either could work.

Starting point for coding a virtual device

I want to write something like DaemonTools: a software that presents itself to the system as a real device (a DVD-ROM in the previous example) but it reads the data from a file instead. My requirement is not limited to DVD-ROM. The first goal is a joystick/gamepad for Windows.
I'm a web developer, so I don't know from where I could start such a project. I believe it will have to be written in C/C++, but other than that, I have no clue where to start.
Did anyone tried something like this and can give me some starting tips ?
Most drivers are written in either C or C++, so if you don't know those languages reasonably well, you'll want to get familiar with them before you start. Windows programming uses a lot of interesting shortcuts that might be confusing to a beginner - for example PVOIDs (typedef void* PVOID) and LPVOIDs (typedef void* far LPVOD;). You'll need to be happy with pointers as concepts as well as structures because you'll be using a lot of them. I'd suggest writing a really straightforward win32 app as an exercise in getting to grips with the Windows style of doing C/C++.
Your next port of call then is to navigate the Windows Driver Kit - specifically, you'll need it to build drivers for Windows. At this stage my ability to advise really depends on what you're doing and the hardware you have available etc, or whether or not you're really using hardware. You'll need to know how to drive your hardware and from there you'll need to choose an appropriate way of writing a driver - there are several different types of driver depending on what you need to achieve and it might be you can plug into one of these.
The windows driver kit contains quite a large number of samples, including a driver that implements a virtual toaster. These should provide you with starting points.
I strongly suggest you do the testing of this in a virtual machine. If your driver successfully builds, but causes a runtime error, the result could well crash windows entirely if you're in kernel-mode. You will therefore save yourself some pain by being able to revert the virtual machine if you damage it, as well as not having to wait on your system restarting. It'll also make debugging easier as virtual serial cables can be used.
This is quite a big undertaking, so before you start, I'd research Windows development more thoroughly - check you can't do it using the Windows APIs first, then have a look at the user-mode driver framework, then finally and only if you need to, look at the kernel level stuff.

What modbus library should I use for modbus protocol for GCC

We are building a product, which requires modbus communication (both rs-485 and TCP/IP). The code has to run on an embedded device which has Linux running on it. We have following criteria for the selecting the library that we would be using.
It has to be opensource, since we are opensource geeks.
We would give this product to our users and what their application would be we are not aware, hence it has to complete implementation of the modbus protocol.
Wide user base: What we believe is that greater the users of the code, more the stability of the code.
I came across two such libraries:
http://www.freemodbus.org
and
libmodbus
Are there any more modbus libraries. Please suggest with pros and cons
I'd suggest libmodbus, it works well and is cross platform.
http://www.libmodbus.org
I am just starting to explore these options as well. My priority is on ease of use which has led me to RModBus since it was the only one that I was able to get immediate results with. However, there is also a Python library, Pymodbus, that appears to be quite complete in implementation.
I'm sorry, I just figured out that GCC is a compiler; my answer is way off topic.
Again, I was looking for a scripting language that my noob self could be more comfortable in. It really came down to a question of language rather than the library itself. Oh, I am only using the TCP/IP stack at this time, which somewhat simplifies it as well.

LPT control on Windows

I am into new project, which should use microcontroller. The easiest way to program it is using parallel port. But, there are few things I hope you can help me with. Oh, and the preferred language is C and platform Windows.
So, I studied LPT ports and Windows a bit, and from what I learned the most important is: Since Windows NT based systems, you cannot use instructions for direct port manipulation. This should be, because now programs are run in different privilege mode, which doesn't support the kind of instructions that are used by outport() function.
But at this point, I don´t understand a few things. First, I thought that Windows actually used privilege levels since first protected mode version, but that's the wrong assumption.
But more importantly, I thought that Windows has included functions for just about any hardware communication. I mean, anything you do in Windows these days, you just call windows functions which further call kernel services. I assumed that outport() doesn´t use any Windows function, and just makes the communication itself, which is prohibited now. But I am literally shocked that there is no system function to control parallel ports in modern Windows systems. At least that's what I read.
But even if I could get the control of parallel port, there comes my second problem.
For programming the controller, I need to follow special protocol, especially timing. But since Windows is multitasked, I worry about what if Scheduler switches to another app, and therefore when is the right time to switch signals on LPT, my program just will not be able to run.
Oh, by the way, I know I could use any 3rd-party apps, but I just like to be able to do it myself, or at least before I use some 3rd-party app, I want to know how it works. And yes, you can program some microcontrollers just by parallel port with some resistors, I know this for sure.
Thanks.
For windows you need to install a DLL which contains a driver to run at elevated privileges to get access to the HW ports.
You can find such a library at :
http://logix4u.net/Legacy_Ports/Parallel_Port/Inpout32.dll_for_Windows_98/2000/NT/XP.html
There are also some links to sample code.
I do not know which uController you are using, but I programmed in the past a variety of them and never had issues with timings, well for programming at least. The programming protocols are usually robust enough to deal with the jitter caused by multitasking. Just keep your clock edges and signa edges well separated and it should go fine.

How to create a virtual printer in Windows?

I want to create a virtual printer driver for Windows. How and where can I start properly? The WDK has some printing drivers examples that do not seems a good introductory. MSDN also doesn't seems to be very helpful for a novice.
There are a lot of virtual printers for Windows out there (mostly they generate PDFs), I wonder if someone could tell my how can I do the same?
Any links to the elaborating documentations are appreciated in advance.
Thanks.
When I did it (which about 12 years ago) I started with the postscript driver sample, replaced all the postscript-specific stuff (in my case, to write to a bitmap instead of generating postscript commands).
I also wrote a custom print monitor (the driver writes to the spooler, which write to a monitor): my monitor wrote to a file instead of e.g. to the parallel port.
However, printer driver architecture and/or the set of sample drivers may have changed since then.
You can look to the 'minidriver' development in the from Microsoft (Microsoft MDT), that might help depending on your exact needs. If the port you need to deal with (ie: you are going to take the data from an existing printer driver and want to process) you could look to the source code for RedMon. It doesn't support Vista/Win7 but might point you in the right direction.
This book maybe help you Developing Drivers with the Windows® Driver Foundation
A list of my links
http://www.codeproject.com/KB/system/driverdev.aspx
http://www.microsoft.com/whdc/ddk/winddk.mspx
http://jungo.com/wdusb.html
https://web.archive.org/web/20130717135254/https://msdn.microsoft.com/en-us/library/ff554651.aspx
http://channel9.msdn.com/posts/Rory/Driver-Development-and-Much-More-With-Mike-Calligaro/
One of the drivers you mention is open-source (GPL), maybe you could explore its source or adapt it: http://www.pdfforge.org/products/pdfcreator/download
Someone else already mentioned PDFCreator. Here's a more specific link to their code that's creating the printer, port and monitor. Despite being in VB, I can follow it as someone more used to C++, so I guess you can too. modPrinter.bas does the leg work. modMain.bas, from about line 28 onwards, calls into modPrinter.bas.
Create a Print Port Monitor, associate that port with a printer, and you'll get the data the printer driver sends to the port.
working example of how is it done in Cpp and java can be found here:
http://www.mms-computing.co.uk/uk/co/mmscomputing/device/printmonitor/index.php

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