On this date 65 years ago, February 1st 1953, the Netherlands experienced its greatest flood till date, the North Sea Flood of 1953. This is still one of the biggest disasters the Netherlands has ever experienced, with thousands of casualties and lots of people who lost their homes.

The Netherlands earns its name from the fact that large parts of the country lie below sea level. To make sure our country doesn’t flood, we have built lots of barriers, dams and dykes to keep the water out, and we want to prevent anything like the flood of 1953 from happening ever again.

In the beginning of this year, several of these barriers and dams were put to the test when a heavy storm reached the Netherlands which resulted in very high water levels. Our five biggest dams and barriers needed to be closed at the same time, a first since their construction. We can ask ourselves the question whether this will happen more often now that sea levels are rising due to global warming 1. A higher base line sea level increases the chance for even higher water levels when it storms. To get an idea what areas would be affected the most by a possible flood, we have created a visualisation project that shows the height of the Netherlands in comparison to the sea level.

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Part of my Google Summer of Code project involves porting several arrow heads from Glumpy to Vispy. I also want to make a slight change to them: the arrow heads in Glumpy include an arrow body, I want to remove that to make sure you can put an arrow head on every type of line you want.

Making a change like that requires that you understand how those shapes are drawn. And for someone without a background in computer graphics this took some thorough investigation of the code and the techniques used. This article is aimed at people like me: good enough programming skills and linear algebra knowledge, but almost no former experience with OpenGL or computer graphics in general.

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Welcome to my first AVR tutorial on this site! We’ll be doing something basic today, namely controlling a servo. There are a lot of tutorials on how to control it with an Arduino, but less tutorials using only a bare AVR chip. In this tutorial we’ll be using the ATTiny44, a small and cheap microprocessor, which also contains a 16 bit timer, which will make our life a bit easier.

Servos are often used to move robot arms and things alike, because they can rotate a specific amount of degrees very precisely, depending on the pulsewidth you feed it with the microcontroller. They can also be used as a motor (you’ll need special ‘continuous rotation’ servos for that), you’ll often find them in RC cars.

So lets get started, and see how you actually control a servo!

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Projects

PHASM: Haplotype-aware de novo genome assembly

A de novo genome assembler written in Python that leverages the assembly graph to output DNA sequences for each haplotype.

Raspberry Pi TLC5940 library

A C++ library to control the TLC5940 LED driver from your Raspberry Pi