Author Archives: admin

Carburettor synchronization

I'm a happy owner of Yamaha XJR1300 which I still consider to be the most beautiful bike. Yeah sure it is not a beast one would take to challenge R1 or CBR1000 on the track days but it certainly is a machine that will … Continue reading

Posted in Motorbikes | Leave a comment

Real-time visualization of electric power consumption

Yesterday I have showed how to read power consumption with a cheap power monitor device. Today I'm gonna put together very basic server and client web applications to store the power usage information in a DB and visualize them in a … Continue reading

Posted in Home automation | Leave a comment

Electricity power monitor hacking

A while ago, while browsing through a local Maplin store, I found a cheap wireless electricity power meter that is possible to connect to a PC via USB cable. Since I was planning to experiment with the electricity power monitoring … Continue reading

Posted in Home automation | Leave a comment

Building Linux for Pandaboard ES

Experimentation with the Skype runtime on the igepv2 board resulted in many days of frustration and endless performance diagnostic leading to a decision to focus on slightly more powerful platform. The Skype audio/video communication works OK on the igepv2 board … Continue reading

Posted in ARM, Embedded, Linux | Leave a comment

Matrix exponential to the Rodrigues' rotation formula

Last time we have seen where the formula came from and today I will try to describe how to do the matrix exponential by means of sine and cosine of the rotation angle and some multiplication and addition. As we will see … Continue reading

Posted in Computer Vision | Leave a comment

Rotation matrix to angle-axis

This time I'm gonna go through a process of extracting rotation axis and angle from the rotation matrix . Lets recap some properties of the rotation matrix that we will be using. Is a square matrix. Is normalized, column and row vectors … Continue reading

Posted in Computer Vision | Leave a comment

Rotation matrix from exponential twist

Last time I described how to derive a geometric derivation of the the famous Rodrigues' rotation formula. While being quite easy to understand there is another way how to get the rotation matrix from the angle-axis representation.  The approach I'm gonna … Continue reading

Posted in Computer Vision | Leave a comment

Rodrigues' rotation formula

In many areas of robotics, computer vision and graphic is a need to rotate points or objects by certain angle around a given axis. One way to do it is to use Rodrigue's rotation formula. Where the is a skew … Continue reading

Posted in Computer Vision | 4 Comments

Running Skype on an embedded device - video. Part 3

And now something even more interesting..... a Skype video calling from our ARM embedded device. Unlike the SkypeKit desktop version the one for embedded devices supports only H264 over RTP. This is no problem since I would need to use it … Continue reading

Posted in ARM, Embedded, Skype, Software development, Video calling, VoIP | Leave a comment

Running Skype on an embedded device - audio. Part 2

Last time In the article Running Skype on an embedded device. Part 1 I have described how to install and build the SkypeKit API wrapper and the Skype client demo application. I admit it was quite boring mainly because the demo even … Continue reading

Posted in ARM, Embedded, Skype, Software development, VoIP | Leave a comment