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Tag: Qt

QtVirtualKeyboard on Wayland

QtVirtualKeyboard on Wayland

For the last couple of years my focus was on the Osmocom project to bring Free Software to the world of telecommunication. With a group of enthusiasts we have implemented the components necessary to run a complete network using Free Software. The Rhizomatica project is using the software to connecting people that were left behind. Our tools enabled high impact security research leading, leading to improvements to privacy and security for all of us…. But during the last months I had…

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Static binaries (for Go with Docker)

Static binaries (for Go with Docker)

These days Go is quite popular for server based systems (read “cloud”) and one of the nice attributes is that compiling an application results in a single binary with no external dependencies (there is no “runtime” it has to link to). This makes deploying (read “copy to machine”) super easy and is a big contrast to something like Ruby on Rails and its thousands of dependencies. IIRC this feature was attractive to the developers of Qt’s coin (continuous integration agent)…

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Captain obvious: Sign a contract before starting to work

Captain obvious: Sign a contract before starting to work

I have worked as a freelancer for more than a decade and was very very fortunate with the projects and partners I had. I apparently let my guards down a little bit too much and this is a reminder what to look-out for. I have nice memories working with the Trolltech PSO team and helping with architecture, performance and low-level debugging in South Korea but when Nokia stopped investing into Qt my work on Qt and QtWebKit halted and I moved to…

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Analyze cellular problems using Quectel modules

Analyze cellular problems using Quectel modules

Introduction Previously I have written about connectivity options for IoT devices and today I assume that a cellular technology (e.g. names like GSM, 3G, UMTS, LTE, 4G) has been chosen. Unless you are a big vendor you will end up using a module (instead of a chipset) and either you are curious what the module is doing behind its AT command interface or you are trying to understand a real problem. The following is going to help you or at least…

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Collecting network traffic, ØMQ and packetbeat

Collecting network traffic, ØMQ and packetbeat

As part of running infrastructure it might make sense or be required to store logs of transactions. A good way might be to capture the raw unmodified network traffic. For our GSM backend this is what we (have) to do and I wrote a client that is using libpcap to capture data and sends it to a central server for storing the trace. The system is rather simple and in production at various customers. The benefit of having a central server…

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Connectivity options for mobile M2M/IoT/Connected devices

Connectivity options for mobile M2M/IoT/Connected devices

Many of us deal or will deal with (connected) M2M/IoT devices. This might be writing firmware for microcontrollers, using a RTOS like NuttX or a full blown Unix (like) operating system like FreeBSD or Yocto/Poky Linux, creating and building code to run on the device, processing data in the backend or somewhere inbetween. Many of these devices will have sensors to collect data like GNSS position/time, temperature, light detector, measuring acceleration, see airplanes, detect lightnings, etc.The backend problem is work but mostly “solved”….

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Leaving Berlin, saying hello to Amsterdam

Leaving Berlin, saying hello to Amsterdam

Berlin continues to gain a lot of popularity, culturally and culinarily it is an awesome place and besides increasing rents it still remains more affordable than other cities. In terms of economy Berlin attracts new companies and branches/offices as well. At the same time I felt the itch and it was time to leave my home town once again. In the end I settled for the bicycle friendly (and sometimes sunny) city of Amsterdam. My main interest remains building reliable…

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C++, Qt and Treefrog to build user facing web applications

C++, Qt and Treefrog to build user facing web applications

In the past I have written about my usage of Tufao and Qt to build REST services. This time I am writing about my experience of using the TreeFrog framework to build a full web application. You might wonder why one would want to build such a thing in a statically and compiled language instead of something more dynamic. There are a few reasons for it: Performance: The application is intended to run on our sysmoBTS GSM Basestation (TI Davinci DM644x). By modern…

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A C++ project without Qt

A C++ project without Qt

My primary language is Smalltalk (Pharo and GNU Smalltalk) and I didn’t write much C++1x code yet and for a new project I decided to use C++ and experiment. The task was rather simple, receive a message, check if this message type needs to be re-written, start to parse it, make a MongoDB look-up, patch it, send it. While looking for MongoDB drivers for Qt I only found the pure C++ driver that is working with std::string, exceptions and only…

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Playing with QV4

Playing with QV4

QtDeclarative is where the fun is. Starting with Qt5.2 a JavaScript Engine written by Digia is used. Compared to JavaScriptCore and V8 this engine is very basic but tightly integrated with the QML and Quick code. Motivated by attending the Qt Developer Summit and my work on GNU Smalltalk I started to look at the VM. There are some environment variables that help to see what the JavaScript VM is doing and also how it is doing things. The below…

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