I have used QextSerialPort for many years and am very happy with it. Usually one would build it as a shared library and link your own applications and libraries to it in the usual way (ie edit the LIBS variable in your .pro file).
As for your second question, how you receive the data back is entirely dependent upon what protocol your serial device is using layered on top of the standard RS232 comms protocol. A library like QextSerialPort and the OS take care of the RS232 part but you are responsible for anything above that.
If you can get the bytes of your 128x128 greyscale image then you can create a QImage from them (see the many QImage constructors). You can then use a QLabel (or your own custom widget and QPainter) to show the image.
Just tried adding the QMainWindow sub class to the MdiArea and it worked perfectly. One thing that I want is to always have it maximized and to not allow the user to minimize it or restore to the original size.
[quote author="kruvva" date="1306436734"]
When I write data to the port, it is triggering the ReadPacket() slot for every byte in the data. I want the slot to be triggered only once when the new data is arrived. How can I achieve this? Is there some thing wrong in the port settings?[/quote]
How would the class know that all your data (or all the data you are interested in) has arrived?
If you get your data in bursts (a block of data, then nothing for a little while, then another block of data), you may look into "this wiki entry":http://developer.qt.nokia.com/wiki/Delay_action_to_wait_for_user_interaction. I explain how to fix this issue when related to UI's, but the code is equally applicable to this case. Or alternatively, you can simply check how many bytes are available when the slot is triggered, and if that number is too low, don't do anything.
Most GPS's are simply serial devices. You could use QextSerialPort to open the port your device talks at. The output stream is most likely NMEA (refer to your GPS manual for details on communication speeds and protocol used).
[quote author="Franzk" date="1297181733"][quote author="SolarQuark" date="1297181527"]Isn't this Qt stuff nice?[/quote]Just in case this was a sneer at Qt, Qwt is not maintained by Nokia.
Anyway, you're welcome.[/quote]
I genuinely think this Qt stuff is amazing.
It is not that long ago that someone like me really had a choice of VB/Delphi/or trying to write some graphics using the windows api and c (Petzold?).
Life was, and still is, far too short.
I did not even know of the existence of Qt, wxWidgets, FLTK, GTK, FOX, et al, until I recently began to do some research into modern C/C++ development platforms and if it was possible to program for a 'modern' (is there ever such a thing?) OS.
And so, in trying to teach myself C++, I tripped across the above technologies and, having researched as much as was reasonable, or perhaps even unreasonable, I decided to learn C++/Qt in parallel.
I do not regret that decision - despite my slowness of mind - and I genuinely am stunned by the capabilities of Qt. I wish, I wish, I wish that the documentation for Qwt was half as good as that for Qt though.
You are right.. I thought that the lib file was an import library.
I also tried to create an import library for qwt but I only got a .dll because I don´t have a the headers files __declspec definitions (implicit use of .dll). Is there any way to create a .dll without changing the header files?
Once I wrote a GPS application, but I parsed NMEA sentences by myself, cause at that time there was no QtMobility. QExtSerialPort works fine, as long as your GPS is seen on your desktop as a COM device (virtual or not).
I'm looking for a plotting library that can plot data interactively. Specifically, I wish to render 1D histogram like curves that are spline smoothed, allow overlay with seperate axes on the left and right. The plots need to be rendered as "filled" plots (i.e. color under the curve), but the fill area needs to be controllable by user interaction. Automatic scaling, labeling, legending, and coloring would also be nice. The qwt library almost delivers what I need. However, I find its interface non-intuitive and its 2D plot rendering leaves a lot of features out.
I looked at KD Chart, and it may be what I am looking for. Of course, I'm only interested in free, open-source solutions.
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