USB Communication Using Qt
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/dev/ttyUSB0 is simply the name that the kernel (or udev or whatever else you are using) assigns to serial over USB devices ie when using a usb-serial convertor. So when using this type of device under windows the corresponding device is COM1.
If you are not using a usb-serial convertor then you have to use the libusb functionality for communicating - that is you cannot simply use COM1 etc.
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[quote author="Andre" date="1303983404"]Could you not use QExtSerialPort to simply list the available ports, instead of guessing their names?[/quote]
Not that I am aware off. Probably, you have to do it brute force by checking all com ports.
[quote author="ZapB" date="1303983794"]If you are not using a usb-serial convertor then you have to use the libusb functionality for communicating - that is you cannot simply use COM1 etc.[/quote]
That gives me something to chew on...
Thanks for your valuable responses
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[quote author="koahnig" date="1303984402"]
[quote author="Andre" date="1303983404"]Could you not use QExtSerialPort to simply list the available ports, instead of guessing their names?[/quote]Not that I am aware off. Probably, you have to do it brute force by checking all com ports.
[/quote]
There is an enumerator in the source code: http://qextserialport.cvs.sourceforge.net/viewvc/qextserialport/qextserialport/
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[quote author="Andre" date="1303985184"]
There is an enumerator in the source code: http://qextserialport.cvs.sourceforge.net/viewvc/qextserialport/qextserialport/
[/quote]you mean the enum on NamingConvention ?
I did not come across this yet. But it is nowherelse referenced. So it could be dead source. -
I mean this class: http://qextserialport.cvs.sourceforge.net/viewvc/qextserialport/qextserialport/qextserialenumerator.h?revision=1.3&view=markup
Sure, old code, and not in the docs, but the code is there...
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BTW the sourceforge project is no longer active. The new home is "here":http://code.google.com/p/qextserialport/
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@Koahnig, if I don't come right with libusb I can fall back on serial to USB as you suggested. Tnx for the link to qextserport.
@ZapB, tnx for the info serial to USB converter chip. If required I will modify my hardware and go the serial route.
I will post here again on completion of the project with info on how to do it for others that might find it useful. -
@Candiman Thx for feedback. Good to know that it helped. Good luck with your project. Please make sure to post a link in this thread. I am interested to see the outcome.
@ZapB Thx for updated link. Wasn't aware of this. There seem to be a couple of derivatives of the source floating around. Actually I started out with one, but some things required reversal. So it is good to know where the original source code is. Have fun. -
@all
Hi, I have found this thread because I have a similar problem.
I have to communicate with a serial external device folowing a simple yet precise protocol. I have tried a fast test to develop the protocol using RXTCComm java library that works not so good and now I was searching for a Qt approach that is the final goal of the other side of the device.
I try to put all your advices together and see if a working stuff can be done. If it maybe useful I put the project on the project area so who is interested can follow. As the project is ready and setup it will be on projects.forum.nokia.com/mill-machine I will announce it on t the forum appropriate area and in the Qt embedded group.
Cheers.
Anticipating many thanks to all.
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Hi. I have used rs232 communication in visual c++ 6.0
which work very well. But because of my problem with
transmit images trough socket in VC++ which is
too complicated than Qt implementation ( very simple ).
I need to implement rs232 comunication.
My interface have to use TCP socket for internet comunication and rs232 for comunicate with microcontroller
and electrical devices. -
Hi dan_geo, let me know if you get your RS232 comms working with Qt. I have had to shift focus to a different project but during the downtime over the December holidays and from Jan 2012 I will be putting effort into the USB via Qt project again since many of my projects can benefit from having a GUI that I can design with Qt. I decided not to go with the RS232 option because so many PCs these days don't have a serial port. USB to serial converters are cheap, but if I can communicate directly with my device using USB then I don't need any additional hardware / drivers etc.
Good luck! -
I have not get rs232 comm. Next days i will try to
implement them in Qt. If you are a source, please
sent to me. About usb, this task i will do later
with PIC18F4455. At usb i understand that
for make a host usb is more complicated than
implement a usb client for example a controller. -
What its the best to access USB port:
http://doc.qt.nokia.com/qtextended4.4/qserialport.html
http://code.google.com/p/qextserialport/
http://qt-apps.org/content/show.php/QSerialDevice?content=112039 (Updated)
Thanks.
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According to "this post":http://qt-project.org/forums/viewthread/15580/#90074 there is a wiki on "QtSerialPort":http://qt-project.org/wiki/QtSerialPort Apparently, the source is inherited from QSerialDevice.
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It's possible to use the QtSerialPort on QT4? On this page (see: http://qt-project.org/wiki/Building-Qt-5-from-Git#15e7b6ad3df43ff719f8388ab4afb1cc) show thats is possible but he only explains to build in qt5!
Anyone is using on QT4? The example there show only to build on Windows, not on linux...
