Friday, July 24, 2009

Little Drummer Robot

Someone made a robot that searches for a "beatable object". When the robot finds this object, it lays down a funky groove ... and I think it's brilliant.

Monday, July 13, 2009

Qt - Arduino Serial Communication

If you want to make a Qt application capable of serial communication with an Arduino, then these are some great resources to do so:
* QextSerialPort : cross-platform serial port library
* Arduino Serial reference : awesome Arduino documentation


I had some trouble getting the QextSerialPort library to work with VS 2008, so I will just go over all steps I needed to take.
* Run this command in the QextSerialPort directory: qmake -tp vc : this will make a .vcproj file from the .pro file
* Open the .vcproj file with VS 2008
* Change the configuration type from dynamic library to static library [as the original setting did not produce a .lib file]

.. and you are ready to go.


Saturday, July 4, 2009

Qt - Ogre - VS2008 Express

This post describes the steps necessary for getting Qt, Ogre and Visual Studio 2008 Express to work, as well as the code for a very basic OgreWidget.

Compile Qt with VS 2008 Express
  1. Download and install Visual Studio Visual C++ 2008 Express Edition

  2. Download the source code of the Qt libraries

  3. Extract the zip to a path without spaces: e.g. C:\Qt

  4. Open the Visual Studio prompt: programs->visual studio 2008-> vs 2008 tools-> vs 2008 command prompt

    • Go to the Qt dir

    • Type: configure

    • Type: nmake [this may take several hours]

  5. Setup path and VS 2008 directories

    • Add an environment variable: QTDIR=C:\Qt

    • Add to the path: %QTDIR%\bin

    • Check if the previous is done right by opening a command prompt and typing: qmake [if this shows the help of this command, it is ok]

    • Add $(QTDIR)\include to the VS 2008 VC++ include directories

    • Add $(QTDIR)\lib to the VS 2008 VC++ library directories

Set up Ogre

  1. Download and install Ogre SDK for Visual C++ 2008

  2. Add OGRE_HOME to the environment variables: e.g. OGRE_HOME=C:\OgreSDK

A Qt/Ogre project in VS 2008 Express

You will need a few .pro files setting up your Qt/Ogre project.
It can all be placed into one file, but it might be convenient to split it into several files for easier reuse. : Change your ogre home directory

win32 {
# You may need to change this include directory
Release:LIBS += -L$$OGREHOME\bin\release
Debug:LIBS += -L$$OGREHOME\bin\debug

For each project a separate project file. : the sources and headers need to be edited, obviously

else:message("I can't find settings file")

CONFIG(debug, debug|release) {
LIBS *= -lOgreMain_d

CONFIG(release, debug|release) {
LIBS *= -lOgreMain

CONFIG += qt warn_on
SOURCES += Main.cpp OgreWidget.cpp
HEADERS += Main.h MainUI.h OgreWidget.h

win32:debug:CONFIG += console

This is a basic config to configure a Qt/Ogre application.
This project file assumes the file is one directory up.

Read more about Qmake project files: here

Now we set up the actual Visual Studio project:
File->New Project->Visual C++ ->General->Makefile Project
Go to the project properties (for All Configurations):
Configuration Properties -> NMake -> General

Build Command Line:qmake && nmake $(ConfigurationName)
Rebuild Command Line:qmake && nmake $(ConfigurationName)-clean && nmake $(ConfigurationName)
Clean Command Line:nmake $(ConfigurationName)-clean

This will tell your Visual Studio to use qmake, which will convert the .pro files to a makefile for nmake, and to compile this file with nmake.

Qt/Ogre IntelliSense setup

Go to the project properties (for All Configurations):
Configuration Properties -> NMake -> IntelliSense

Common Language Runtime SupportCommon Language Runtime Support (/clr)
Include search path"$(QTDIR)\include";"$(OGRE_HOME)\include"

An OgreWidget implementation

I've tried to create a very basic OgreWidget which subclasses a QWidget. Most of the code was taken from a couple of the sources below, taking only the parts which are strictly necessary and leaving out all redundant code. The widget only renders the Ogre scene, it does not handle any user input.

Here is a code snippet on how to use this OgreWidget:
In a QMainWindow:

m_pWidget = new QtOgre::OgreWidget(this);
//Add the widget to the QMainWindow
//uncomment code below for fullscreen
//Hide all the GUI stuff you do not want to see fullscreen

Easy, isn't it?

Now you set up the Ogre scene:

//Create the scene manager
mSceneManager = Ogre::Root::getSingleton().createSceneManager(Ogre::ST_GENERIC, "GenericSceneManager");
//Create the camera
mCamera = mSceneManager->createCamera("Cam");
//Add a viewport to the render window from the OgreWidget

Of course your Ogre code will become much more ellaborate, but this is the minimum you need to render an Ogre scene inside a Qt Window.

I hope this is useful to someone :)



Qt and VS 1
Qt and VS 2
Qt and VS 3
Qt and Ogre 1
Qt and Ogre 2
Qt and Ogre 3

Thursday, July 2, 2009

Plexiglass Skybluepink Frame

I made this as another gift to a friend of mine, namely the drummer in my band (Skybluepink). It is a frame with the name of the band and two blinking leds behind it. It has an on/off switch and it runs on a 9V battery. Yes, it's not very high tech.

Score and Snap-method
One of the difficult parts in creating this, was transforming a broken piece of plexiglass I found somewhere, into the shapes I needed for this object. As it turns out, using an ironsaw is a very bad idea. The best results I got, was by scoring it with a cutterknife a couple of times and then snapping it along the groove made by the knife, hoping that it did not snap in the wrong places :)

The other difficult part was the painting of the plexiglass. My buddy JD created a drawing which I cut out from a transparency sheet. I placed this shape over the plexiglass and then I spray-painted it. The problem was that a bit of the paint went under the cut-out shape, causing a lot of work the manually remove the excess paint. The best way to prevent this, is to make sure that the shape will not bend and is completely taped to the surface you are spray-painting.

The video

Some pictures