Starting a project – the open source way


You should start/build your project in a way where anyone can help you build it or evolve your work.

What’s the purpose of building something on your own when you can build it faster and in a more efficient way with others?

Nowadays we have all the tools and resources we need in order to start our own project. Stack overflow, github, instructables and hackaday are only a few of the available resources/tools which will help you build the most challenging hardware or software project.

But how we engage more people in our building process in order to achieve great things together?

Continue reading

Install fonts in Linux



You just downloaded some cool fonts and you want to use them on your presentation at LibreOffice Presentation.

The fonts are some *.ttf files and you don’t know how to use them or where to put them.


Create a folder named “.fonts” in your home directory and place the files in there. It is a “hidden”, system folder located in your system account’s home directory.

Open LibreOffice and you are ready!

mkdir ~/.fonts

Enjoy 🙂

Invert colours in PDF files


Today I faced to following problem.

I wanted to print an ugly presentation which was stored in a PDF file. And I say ugly because the background was bright blue and the font of the text, yellow!

Printing this beauty in a printer will definitely empty all the ink in the first 10 pages. That’s why we have to invert the colours in order to consume less ink in printing.

After an hour of searching on the web I came out with empty hands! I have only managed to apply a Gray scale on the PDF using the convert command:

convert uglyPresentation.pdf -colorspace gray prettierPresentation.pdf

I am still having the same problem. The background instead of the ugly bright blue is ugly black/gray.

So I started reading the man page of the convert tool instead of searching on the web. Finally I came up with the -negate argument which replace each pixel with its complementary color.

convert prettierPresentation.pdf -negate beautifulPresentation.pdf

And we are set! Now I can print my presentation consuming less ink!

Conclusion: Read The F*** Manual

It is also well mentioned that you can invert or change the colorspace in other file types, like images.