C++ code to estimate Solar Azimuth and Elevation given GPS position and time. For reasons that I won’t go into here I found it necessary to estimate Solar Azimuth and Elevation given GPS position and time. Now there is quite a bit of information on how to this on the old inter-web, none of it […]
Anybody who works with images often have probably come across .Net Bitmaps (System.Drawing.Bitmap) with their staggeringly slow GetPixel() and SetPixel() methods. Now, if you are going to work directly with images then you’re probably in the wrong place if you are using C# and .Net. However, sometimes you may want to do a small amount […]
I couldn’t get KDevelop to stop at breakpoints even on simple ‘hello world’ C++ projects. It appeared that CMAKE_BUILD_TYPE was being correctly set and GDB worked fine from the command-line, but from within kdevelop breakpoints were never respected! I think the problem stemmed from the Cache Value for CMAKE_BUILD_TYPE being empty, this value can be […]
To sleep in your shell script in units of 1 second – sleep will see you right. However what if you want to sleep for less than one second, say for 200ms? On some newer system you can do something like this and everything is fine:
1 | sleep .2 |
However when I try this on my embedded […]
Sending data to a serial port is quite easy in Bash, for example:
1 | echo "my packet data" > /dev/ttyS0 |
And you can read from a serial port using cat:
1 | cat /dev/ttyS0 |
However cat must typically be run from a different shell instance as it blocks waiting for data. So is it possible to write and then read the response from a […]
If you’re receiving errors like the following when trying to build a project in Visual Studio 2017 using the Paho C client:
1 | Error C2238 unexpected token(s) preceding ';' |
Then there is a quick fix, the problem seems to revolve around the following for DLLImport & DLLExport in the Paho header files:
1 2 3 4 5 6 7 | #if defined(WIN32) || defined(WIN64) #define DLLImport __declspec(dllimport) #define DLLExport __declspec(dllexport) #else #define DLLImport extern #define DLLExport __attribute__ ((visibility ("default"))) #endif |
The catch here is that neither WIN32 nor […]
The point cloud library (PCL) is a fantastic resource for working with point clouds, however it is a large library and it can take a while to effectively find your way around it. The octree construct is very useful for working with point clouds, but again it can take a while to learn how to […]
If you get this compile error: Error C2988 unrecognizable template declaration/definition When you:
1 | #include <pcl/octree/octree.h> |
from the Point Cloud Library (PCL) in Visual Studio 2017, then either throw the following in before the #include, like this:
1 2 3 4 | // #define BOOST_TYPEOF_EMULATION #include <pcl/octree/octree.h> |
or upgrade your version of Visual Studio 2017 (I haven’t tested this yet myself!) Not sure why, it’s something […]
Phil Harvey’s ExifTool is a fantastic software tool for displaying and interacting with image Exif data, however by default it doesn’t display maker notes and I always forget the command line options to persuade it to list them, so here it is – the -u option gets exiftool to display ‘unknown’ tags and theses include […]
In some cases both the MikroC i2c functions I2C1_Wr() and I2C1_Rd() can hang or lockup indefinitely until the PIC is reset. This can happen if the I2C bus isn’t properly terminated, for example if a connection breaks or similar (broken wire or solder joint etc). Having your PIC lockup during operation is generally not very […]