AccuTerm – Serielles Terminal auf dem Blutzuckermessgerät “Accu-Chek”

Vor einiger Zeit habe ich zwei Blutzuckermessgeräte “Accu-Chek Compact Plus” als Auslaufmodelle erstanden. Diese Geräte eignen sich für den Bastler als kleine, preiswerte Plattform für Eigenentwicklungen, da sie in einem praktischen Gehäuse schon folgende Komponenten fix und fertig enthalten: Batteriehalter und Spannungswandler, OLED-Diplay, drei Tasten und ein Piezo-Summer sowie einen kleinen aber feinen Atmega168, den man leicht selbst programmieren kann. Gute Infos zu diesem Gerät gibt es auf der Seite von adriaNo6 oder bei mikrocontroller.net.

Hier möchte ich eine Anwendung dieses Geräts als serielles Terminal vorstellen.

Modis – Closed loop motor control with display (Benham disc)

Information about closed loop motor control is somewhat hard to come by on the Internet. Of course there is a vast body of literature about closed loop controls, but most of these books or articles focus on the mathematical methods of modeling and calculating motor controls. In practice, it is often not easy to apply these methods to a given real-world situation. Consequently these books require an amount of study that can easily overwhelm a hobby constructor who "just needs a simple motor control". On the other hand, simple instructions often are too specific or leave out a lot of useful information, making it difficult to recognize their limitations or adapt them to a given mechanical setup.

Front view of the Benham disc rotator

I am attempting here to provide a fairly detailed description of a closed loop engine controller. This includes a description of the mechanical parts, the circuit boards and finally the software, written in C for an Atmel Atmega 8, as a WinAVR (Programmer’s Notepad) project. You can use this description for projects of your own, and you can use my schematics, layouts and source code freely (where indicated; for exceptions see the descriptions and/or source). However, while I am trying to explain the details as well as I can, you should expect that you need to invest some work of your own to fit your needs and possibilities. Please check everything carefully as neither this description nor the provided files are guaranteed error free!

Download the project files

The Signature Of Buses

Mr. Hartmut Warm, a programmer and engineer, analyzes periodic patterns in the movement of celestial bodies. What he gets is patterns of intricate beauty. He calls these patterns the “signature of spheres”, referring to Pythagoras’ “harmony of the spheres”. I recently came across a (German) documentary and thought this might be an interesting topic to investigate and learn F# on. Here I’m trying to analyze periodic patterns in the movements of bus lines of the city of Constance, calling the results the “signature of buses”.

A strange resources problem in Visual Studio 2010

A strange problem in Visual Studio 2010 haunted us sometimes when working with a larger Visual Studio solution of about 30 projects. The symptom is that seemingly random attributes of visual components in designer generated files refer to resource strings defined in unrelated projects. The effect is that the project will not build any more. A quick solution is to delete the offending lines in the generated Designer.cs file (often this will be something like this.label1.BackgroundStyle.Class = "";) and saving the Designer.cs file separately. This, of course, becomes increasingly annoying.

Others have experienced similar problems as well.

A simple word breaker in C#

Word breakers split longer words (e. g. compound nouns or compounds) into meaningful constituents. They are used with search engines that do not support infix search. While there aren’t many compounds in spoken English the problem is more immanent in languages like German or Swedish. Take for example the notorious “Donaudampfschiffahrtsgesellschaftskapitänsmütze”: A word that is made up from at least seven different words, depending on how you count. The problem is how to split possible compounds into their constituents in an efficient way.