Saturday on a Sunday @ Antikvariatet

The first thing you see when you enter Antikvariatet is a relatively normal cosy pub. Only when you pass through the hall, which looks like it just leads to the rest-rooms, you’ll discover the back-room which is a very curious blend of library, living-room, and bar. This is where last Sunday’s concert and open-mic night took place.
First Edvardsen & Sønn, a really talented and entertaining duo of father and son (or son an father 😉 ), were playing the Blues. Later, the stage was open to anyone interested. And there were plenty! As each of them only played two or three songs, there was a great variety in styles. For the last songs, the singer got a mix of rather surprised musicians on stage. Together they performed an amazing interpretation of the classic ‘I Shall be Released’ (video below).

Edvardsen & Sønn   Lørdag pü Søndag @ Antikvariatet
Lørdag pü Søndag @ Antikvariatet   Lørdag pü Søndag @ Antikvariatet
Lørdag pü Søndag @ Antikvariatet   Lørdag pü Søndag @ Antikvariatet


Drone King of the Hill

The recent Hak5 episode 1903 inspired me to build a King of the Hill version for quadcopters. Shannon and Darren talked about their acrylic drone-fighting cage, the last-man-standing matches they had, and their future plans including a version of king of the hill.

Since then, I’ve been working on my own implementation of the king of the hill idea based on an old ADJD-S311 Color Light Sensor Evaluation Board from Sparkfun which I still had lying around. Combined with an Pololu A-Star 32U4 Micro for the brains, a single button for input, and an LPD8806 based RGB-LED-strip from Adafruit for output, this made a pretty nice tinkering project.

Micro Quadcopter Micro Quadrcopter on Platform

The micro quadcopters are split into 2 to 4 teams and are marked with differently coloured stickers at the bottom (red, green, blue, yellow).
The light sensor in the centre of the platform is initially passive and set to maximum sensitivity. In combination with ambient light, the A-Star Micro can detect whether the sensor is covered or not. As soon as it detects that the sensor is covered, it is set to active mode. It then evaluates reflected light using a white LED and a lower sensitivity setting. Based on the measured rgb-colour, ‘the brains’ decide which team the drone on the platform belongs to.
After a team covered the sensor for 3 seconds to win a point, the platform needs to be cleared for 5 seconds before another winning point can be gained.

Drone King of the Hill Game   Drone King of the Hill Game (animated)

The game play is set-up using the single button. First the number of teams is shown using the LEDs in the vertical stand. Clicking the button iterates between 2, 3, or 4 teams with different colours. After a long-click, the number of winning points are selected. Again by clicking the button 1, 3, 5, or 7 winning points can be selected. The game starts after another long-click with the progress being displayed on the vertical bar. As only a single LED strip is used, additive colour mixing occurs between the teams. The game continues until one of the teams achieves the necessary number of points, upon which the winning team’s colour flashes along the bar in ‘knight rider’ fashion.

Some friends from FIX, the local maker space, and I ordered a whole bunch of Eachine H8 Mini drones. Now we’re looking forward to some awesome team matches the space :-)

The CAD models can be found at Onshape, a really interesting web-based CAD solution done by veterans of Solidworks. (log-in and search for ‘Drone King of the Hill’, couldn’t find a public link … still beta 😉 )
The source code can be found on GitHub and relies on the awesome cross-platform code builder and library manager PlatformIO.

Healthier Soldering

To get rid of the soldering fumes, I re-purposed one of the fans I salvaged from an old office printer:
Soldering Fume Extractor Soldering Fume Extractor - Fan

The fan is hot-glued into a card-board tube which also allows easy positioning of the fume extractor. The flexible tube attached to the end is long enough to reach out of the next window, so no fume filtering is needed.

This makes soldering way more comfortable, and during winter I can fill the window gaps around the exhaust tube with pillows. Smoke-free soldering without freezing! 😀

Hiking on the other side of the fjord

What a tur :-)

I took the ferry to the other side of the fjord in order to hike one of the hills we can see from our side. A friendly farmer let me park my car in his yard and told me about a little trail leading into that area.
Ferry Flakk - Rørvik Farm Parking
Everything afterwards was just barely visible animal trails (thanks animals, nice trails you trampled there :-) ). I even saw a couple of elk in the distance, though too far and quick for a photo! At some point I realised that I would not be able to reach the top I intended to (Munken) and decided to set up camp on another really nice hilltop (slightly north-west of Stegavikdammen). Although this spot was missing the panoramic view across the fjord, it had some funny and very audible sheep in the valley below.
Hiking the back-country Mountain Sheep
What an evening Real Turmat
After a nice warm meal of turmat, I went to bed with a glimpse of the city lights on the other side of the fjord and the stars above (the nights are dark enough again). As I had placed the tent behind a little hill, beautiful sunshine only woke me at about 8 in the morning. After a simple breakfast of bread, cheese, and liver patĂŠ, I headed back following a slightly different path.
City Lights Good Morning Sunshine
Refreshing Lake Ferr Rørvik - Flakk
The new backpack I tested on this trip prove really comfortable and practical. It allows you to open the whole front-side similar to a sports bag. This makes organising and accessing the equipment way easier!

The full set of photos can be found in my OwnCloud.

I ♥ Trd

So it has been slightly over two years now, and I must say I love this place. From beautiful nature, interesting city live, and a good music scene to the new water-front with bbq, it has it all!

Open CAE-CAD-CAM tool chain for airplane design

The last few days (with almost continuous rain outside), I was looking into open source software for airplane design again. It has been a while since I designed my last flying wing with XFoil and AVL, and WOW how things moved forward! With XFLR5 there is now a comfortable environment which integrates most of the functionality XFoil and AVL offer. It also includes really nice post-processing and visualisation.

As I want to try the CNC router at the FIX Maker Space for cutting foam cores of wings, I needed a way to interface XFLR5 with CAD/CAM. Sadly it does not support direct export to any common file format. But I sat down yesterday night and wrote a translator from XFLR5 wing format to ASCII STL files: XFLR5-STL@github
Now I can import the generated STL file in MeshLab, FreeCAD, PyCAM, or OpenSCAM for the next steps towards CNC routed foam cores :-)

Let’s see how that works out!