Archive for category Work

How to weigh your cat! – the IoT version

This is Leela. She is a 7 year old lilac white British short hair cat that lives with us. Leela had a sister who used to live with us as well but she developed a heart condition and passed away last year. Witnessing how quickly such conditions develop and evaluate we thought that we can do something to monitor Leelas health a bit to just have some sort of pre-alert if something is changing.

Kid in a Candystore

As this Internet of Things is becoming a real thing these days I found myself in a candy store when I’ve encountered that there are a couple of really really cheap options to get a small PCB with input/output connectors into my house WiFi network.

One of the main actors of this story is the so called ESP8266. A very small and affordable system-on-a-chip that allows you to run small code portions and connect itself to a wireless network. Even better it comes with several inputs that can be used to do all sorts of wonderful things.

And so it happened that we needed to know the weight of our cat. She seemed to get a bit chubby over time and having a point of reference weight would help to get her back in shape. If you every tried to weigh a cat you know that it’s much easier said than done.

The alternative was quickly brought up: Build a WiFi-connected scale to weigh her litter box every time she is using it. And since I’ve recently bought an evaluation ESP8266 I just had to figure out how to build a scale. Looking around the house I’ve found a broken human scale (electronics fried). Maybe it could be salvaged as a part donor?

A day later I’ve done all the reading on that there is a thing called “load-cell”. Those load cells can be bought in different shapes and sizes and – when connected to a small ADC they deliver – well – a weight value.

I cracked the human scale open and tried to see what was broken. It luckily turned out to have completely fried electronics but the load-cells where good to go.

Look at this load cell:


That brought down the part list of this project to:

  • an ESP8266 – an Adafruit Huzzah in my case
  • a HX711 ADC board to amplify and prepare the signal from the load-cells
  • a human scale with just enough space in the original case to fit the new electronics into and connect everything.

The HX711 board was the only thing I had to order hardware wise – delivered the next day and it was a matter of soldering things together and throwing in a small Arduino IDE sketch.

My soldering and wiring skills are really sub-par. But it worked from the get-go. I was able to set-up a small Arduino sketch and get measurements from the load-cells that seemed reasonable.

Now the hardware was all done – almost too easy. The software would be the important part now. In order to create something flexible I needed to make an important decision: How would the scale tell the world about it’s findings?


Two basic options: PULL or PUSH?

Pull would mean that the ESP8266 would offer a webservice or at least web-server that exposes the measurements in one way or the other. It would mean that a client needs to poll for a new number in regular intervals.

Push would mean that the ESP8266 would connect to a server somewhere and whenever there’s a meaningful measurement done it would send that out to the server. With this option there would be another decision of which technology to use to push the data out.

Now a bit of history: At that time I was just about to re-implement the whole house home automation system I was using for the last 6 years with some more modern/interoperable technologies. For that project I’ve made the decision to have all events (actors and sensors) as well as some additional information being channeled into MQTT topics.

Let’s refer to Wikipedia on this:

“MQTT1 (formerly MQ Telemetry Transport) is an ISO standard (ISO/IEC PRF 20922) publish-subscribe-based “lightweight” messaging protocol for use on top of the TCP/IP protocol. It is designed for connections with remote locations where a “small code footprint” is required or the network bandwidth is limited. The publish-subscribe messaging pattern requires a message broker. Thebroker is responsible for distributing messages to interested clients based on the topic of a message. Andy Stanford-Clark and Arlen Nipper of Cirrus Link Solutions authored the first version of the protocol in 1999.”

Something build for oil-pipelines can’t be wrong for your house – can it?

So MQTT uses the notation of a “topic” to sub-address different entities within it’s network. Think of a topic as just a simple address like “house/litterbox/weight”. And with that topic MQTT allows you to set a value as well.

The alternative to MQTT would have been things like WebSockets to push events out to clients. The decision for the home-automation was done towards MQTT and so far it seems to have been the right call. More and more products and projects available are also focussing on using MQTT as their main message transport.

For the home automation I had already set-up a demo MQTT broker in the house – and so naturally the first call for the litterbox project was to utilize that.

The folks of Adafruit provide the MQTT library with their hardware and within minutes the scale started to send it’s measurements into the “house/litterbox/weight” topic of the house MQTT broker.

Some tweaking and hacking later the litterbox was put together and the actual litterbox set on-top.

Since Adafruit offers platform to also send MQTT messages towards and create neat little dashboards I have set-up a little demo dashboard that shows a selection of data being pushed from the house MQTT broker to the MQTT broker.

These are the raw values which are sent into the weight topic:

You can access it here:

So the implementation done and used now is very simple. On start-up the ESP8622 initialises and resets the weight to 0. It’ll then do frequent weight measurements at the rate it’s configured in the source code. Those weight measurements are being monitored for certain criteria: If there’s a sudden increase it is assumed that “the cat entered the litterbox”. The weight is then monitored and averaged over time. When there’s a sudden drop of weight below a threshold that last “high” measurement is taken as the actual cat weight and sent out to a /weight topic on MQTT. The regular measurements are sent separately to also a configurable MQTT topic.

You can grab the very ugly source code of the Arduino sketch here: litterbox_sourcecode

And off course with a bit of logic this would be the calculated weight topic:

Of course it is not enough to just send data into MQTT topics and be done with it. Of course you want things like logging and data storage. Eventually we also wanted to get some sort of notification when states change or a measurement was taken.

MQTT, the cloud and self-hosted

Since MQTT is enabling a lot of scenarios to implement such actions I am going to touch just the two we are using for our house.

  1. We wanted to get a push notification to our phones whenever a weight measurement was taken – essentially whenever the cat has done something in the litterbox. The easiest solution: Set-Up a recipe on If This Than That (IFTTT) and use PushOver to send out push notifications to whatever device we want.
  2. To log and monitor in some sort of a dashboard the easiest solution seemed to be Adafruits offer. Of course hosted inside our house a combination of InfluxDB to store, Telegraf to gather and insert into InfluxDB and Chronograf to render nice graphs was the best choice.

Since most of the above can be done in the cloud (as of: outside the house with MQTT being the channel out) or inside the house with everything self-hosted. Some additional articles will cover these topics on this blog later.

There’s lots of opportunity to add more logic but as far as our experiments and requirements go we are happy with the results so far – we now regularly get a weight and the added information of how often the cat is using her litterbox. Especially for some medical conditions this is quite interesting and important information to have.

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Gaming: GTA V in Panoramic Views in 4k

Since games get bigger and bigger and their graphic gets more and more impressive I’ve made some panoramic views from In-Game with everything turned to 11.


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31st Chaos Communication Congress


Like every year the Chaos Communication Congress gathered thousands of people in one place between the Christmas-Holidays and NewYears.

Since I was out-of-order this year to attend I’ve opted for the Attending-by-Stream option. All Lectures are live-streamed by the awesome CCC Video Operations Center (C3VOC) and made available as recordings afterwards.

Since the choice of topics is enormous here are some I can recommend:

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in case of emergency: spoof your MAC address



There have been several occasions in the past years that I had to quickly change the MAC address of my computer in order to get proper network connectivity. May it be a corporate network that does not allow me to use my notebook in a guest wifi because the original MAC address is “known” or any other possible reasons you can come up with…

Now this is relatively easy on Mac OS X – you can do it with just one line on the shell. But now there’s an App for that. It’s called Spoof:


“I made this because changing your MAC address in OS X is harder than it should be. The Wi-Fi card needs to be manually disassociated from any connected networks in order for the change to apply correctly – super annoying! Doing this manually each time is tedious and lame.

Instead, just run spoof and change your MAC address in one command. Now for Linux, too!”


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Map, Search and Filter flights all around the world

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“OpenFlights is a tool that lets you map your flights around the world, search and filter them in all sorts of interesting ways, calculate statistics automatically, and share your flights and trips with friends and the entire world (if you wish). It’s also the name of the open-source project to build the tool.”


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blast from the past: a Console Framework for .NET

“Console framework is cross-platform toolkit that allows to develop TUI applications using C# and based on WPF-like concepts.”


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Nitrous – full IDE in your browser – with Collaboration!

“Nitrous is a backend development platform which helps software developers save time by cutting out the repetitive parts of creating development environments and automating them.

Once you create your first development environment, there are many features which will make development easier.”

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So what you’re getting is:

  • a virtual machine operated for you and set-up with a single click
  • A full-featured IDE in your browser
  • Code-Collaboration by inviting others to edit your project
  • a debugging environment in which you can test-run and work with your code

Here are some screenshots to get you a feel for it:


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Scaling Linux: Perfomance Tools and Measurements


If you ever experienced a missmatch between the performance you expected from a server or application running on Linux you probably started to debug your way into it why the applications performance is not on the expected levels.

With Linux being very mature you get an enormous amounts of helpers and interfaces to debug the performance aspects of the operating system and the applications.

Want to see proof? Here – a map of almost all the thingies and interfaces you got:linuxperftools

Thankfully Brendan Gregg put together a page with videos and further links to drill into those interfaces and methods above.


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APN Changer for iOS – when you’re abroad and in need of different mobile provider settings

When traveling you might find yourself in the situation that you get a new SIM card into your iPhone and it’ll start and do it’s automatic magic for you. And eventually you well end up with the right provider settings by default.

But there are some cases when it picks the wrong provider settings. Like in my case. It picked NTT docomo in Japan with the default NTT docomo settings. In my case I was using a reseller for NTT (as described here) and that demanded different provider settings to work.

Unfortunately in all it’s wisdom the iPhone did not allow me to set the carrier settings. It just displayed the “Automatic” choice. So I went to the APN Changer website, entered the settings and installed a custom provider setting to my device. This works without any Jailbreak with iPhones without SIM Lock.


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How to use the Tokyo public transportation system as a visitor

Being in Tokyo as a visitor brings a lot of challenges. Since you gotta use the public transport offers to get from A to B. Now we had the same challenge this May and this is how we tried to solve it.

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Problem: How do you know which train lines you take and where they are?

Solution: Use Google Maps (you need mobile internet access!) to find your route

The public transportation feature of Google Maps works like a charm. It’s accurate as it can be and offers even walking instructions to get to the right platform or train station.

Notice the colored lines next to the different stations. That’s the color you’re looking for on the train. They are color coded! To find your right platform just take the information that Google gives you and look out for it. It will be written on signs “Rinkai towards Tokyo Teleport”.


Problem: Okay I know which train I have to use. But before I enter the platform I have to pass the ticket gate. How do I buy a ticket? How do I know which one?

Solution: Get a Suica card and charge it! If you’re a group travelling: Look out for cheap group ticket offerings.

A Suica card (aka “Super Urban Intelligent Card”) can be used instead of buying a ticket. You can buy it where you can buy the tickets – most of the time it’s 500 Yen + charge. Charging it with some Yen is crucical since the gates will not let you in when your card is not at least charged with 210 Yen.

You may ask: If I buy a ticket from A to B I have to pay the price upfront. When I use the Suica how does it work then? Easy answer: When you enter the train station through the ticket gate you pass it with your Suica card. It will start a journey for you. When you exit it will end the journey. The card and system is intelligent enough to calculate all steps in between, add them up and substract the fare price from your Suica balance. It always takes the cheapest price for single travellers.

If you’re on your way as a group you might want to use the ticket machines before going through the ticket gates. The Suica is a personal card and only suited for one person to be used. So you cannot pass it through the ticket gate back and enter the ticket gate again without causing panic with the service personell.

To buy tickets for groups I suggest to switch the terminals to english – most of them will offer that option. You then have to specifically know where you want to go. Sometimes it’s the easiest way to just go to the counter and buy them there.

Sometimes when you bought tickets you find out that you made a mistake. Fear not! You can give them back and by doing so get your money back. Service personell is awesome and will help you at any time! DO NOT PANIC!

Another awesome feature you get ‘for free’ by having a Suica card is that you can use it with all the vending machines available everywhere in the train stations. Just pick the beverage you want and swipe the card. Done!

Beware: fill the card up before going out of the ticket gate when you used it all up!

If you happen to have a NFC enabled device (like most Android phones) you can install the Suica Reader app from the Google Store and get information about what happened to your card so far.

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how to get mobile Internet (3G / LTE) in Japan

If you visit Japan the next time and you want to get perfectly good Internet access while there on your mobile phone I can recommend the b-mobile offer. On my last stay in Japan (May 2014) I tried their service for the first time and I was not let down.

They give you two options: The 1 GB prepaid option gives you 1 GB as fast as possible. The 14days prepaid gives you 14 days of limited speed coverage (300kbps).

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I went for the 14 days prepaid option knowing that I might get some usage depending on where I go. The 300kbps where faster than I thought – at no given time I experienced any speed problems. The coverage was awesome since it just dialed into NTT Docoms 3G/LTE network.

For just under € 30 this is an awesome option for any traveller. Even better: You can pick it up at the Airport or you can have it delivered to your hotel! We tried both and it worked both as expected. Fast delivery, perfect service!


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Tokyo Trip ahead


Stay tuned here for at least some coverage of this years Japan trip.

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MOSH (Mobile Shell) – fixing SSH for everyone

How many times did you experience a connection loss on your terminal window in the last week? Yeah I know – like everytime you close the lid of your notebook and move to a different place. So like a dozen times every day.

And everytime you reconnect to your servers and you use things like screen to keep your terminals open and your programs running while you’re disconnected.

On the other hand – did you ever curse the internet gods while you tried to do a very important check or bugfix to a machine whilst on a train or mobile roaming network? It’s not what I would call fun-times. When there are no constant disconnects the lag is just infuriating. MOSH also solves this since it’s predicting and responding way faster then vanilla SSH. Your terminal becomes useable again!

So there’s now MOSH to the rescue:

Remote terminal application that allows roaming, supports intermittent connectivity, and provides intelligent local echo and line editing of user keystrokes.
Mosh is a replacement for SSH. It’s more robust and responsive, especially over Wi-Fi, cellular, and long-distance links.
Mosh is free software, available for GNU/Linux, FreeBSD, Solaris, Mac OS X, and Android.

Install it on your servers and your clients and never lose a connection again.

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when javascript equality checks, always use ===

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On-Screen OCR – helps you when all you get is an image…

“You want to extract one paragraph of text from a pdf your coworker sent you? One quote from your professor’s presentation? A couple of code lines from this tutorial clip on your favourite movie platform? It’s just one hotkeypress away. OCR everything on the fly.

Condense is the product of many frustating years of using overly complicated OCR software. “Take a screenshot, boot up your OCR suite, select the area you want to extract, select an output file…” Oftentimes typing out is faster than walking through this procedure.”

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when in Japan – get free Wifi

On a trip in Japan and feeling disconnected? There’s a lot of Wifi around and some of it is free:
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document your REST interfaces with style: Swagger

Swagger is a specification and complete framework implementation for describing, producing, consuming, and visualizing RESTful web services. The overarching goal of Swagger is to enable client and documentation systems to update at the same pace as the server. The documentation of methods, parameters, and models are tightly integrated into the server code, allowing APIs to always stay in sync. With Swagger, deploying managing, and using powerful APIs has never been easier.”

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Cheat Sheet For Starting and Running A Business

Useful advice is right ahead! This cheat sheet gives some very interesting thoughts and advices for your own or others business.

I particularly liked:

“21) Should I ever focus on SEO? No.

22) Should I do social media marketing? No.”


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“Compressing” JSON to JSON



The internet and all those browsers and javascript applications brought data structures that are pretty straight-forward. One of them is JSON.

The wikipedia tells about JSON:

“JSON (/ˈdʒeɪsɒn/ JAY-soun, /ˈdʒeɪsən/ JAY-son), or JavaScript Object Notation, is an open standard format that uses human-readable text to transmit data objects consisting of attribute–value pairs. It is used primarily to transmit data between a server and web application, as an alternative to XML.”

Unfortunately complex JSON can get a bit heavy on the structure itself with over and over repetitions of data-schemes and ids.

There’s RJSON to the rescue on this. It’s backwards compatible and makes your JSON more compressible:

“RJSON converts any JSON data collection into more compact recursive form. Compressed data is still JSON and can be parsed with JSON.parse. RJSON can compress not only homogeneous collections, but also any data sets with free structure.

RJSON is single-pass stream compressor, it extracts data schemes from document, assign each schema unique number and use this number instead of repeating same property names again and again.”

Of course this is all open-source and you can get your hands dirty here.

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Xcode Cheat Sheet

While I am using Xcode a lot lately I quickly got used to one or two keyboard shortcuts that come in handy once every while. This cheat sheet aims at bringing you a lot of shortcuts that are pretty hard to remember if you’re not using them all the time (at least for me).


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the dark side of user interface design



“A Dark Pattern is a type of user interface that appears to have been carefully crafted to trick users into doing things, such as buying insurance with their purchase or signing up for recurring bills.”

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full text transcripts of the Apple World Wide Developer Conference (wwdc)

Since I’ve become sort of an iOS developer lately I had my fair share of WWDC recordings to get started with this whole CocoaTouch and Objective-C development stuff.

Now a tool that is pretty handy is a this website that offers a full-text transcript search of all WWDC recordings. Awesome!

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how a code repository can be visualized

Most development projects are relying on a source code repository these days to have control over the constant changes by many team members. The source code repository is therefore the complete history of a software project.

With the great tool called “gource” you can visualize it! This for example is the project a team from Rakuten Germany (where I work) worked on for the last couple of months:

Source 1: Visualize your source-control
Source 2: Gource

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a kilobyte of javascript – js1k

What do you think can you do with 1 kilobyte of javascript? Not a lot you might think. In fact it’s quite a lot!


Similar to the 4k and 64k demo awards now there is a 1k javascript competition:

“This is a competition about JavaScript scripts no larger than 1k. Starting out as a joke, the first version ended with a serious amount of submissions, prizes and quality.”

So what can you do with 1k of javascript? A lot! Click your way through the demos on the site and find a lot like this:

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a virtual network inside your machine

Did you ever start a horde of virtual machines and a complicated vm-only network set-up just to simulate a medium complex network and the interaction of nodes in that network? Well that’s a tiresome, error-prone and labour intensive process. Fear no more, there’s a tool to the rescue.

“Mininet creates a realistic virtual network, running real kernel, switch and application code, on a single machine (VM, cloud or native), in seconds, with a single command:”


“Because you can easily interact with your network using the Mininet CLI (and API), customize it, share it with others, or deploy it on real hardware, Mininet is useful for development, teaching, and research. Mininet is also a great way to develop, share, and experiment with OpenFlow and Software-Defined Networking systems.

Mininet is actively developed and supported, and is released under a permissive BSD Open Source license. We encourage contribution of code, bug reports/fixes, documentation, and anything else that can improve the system!”


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Adobe Photoshop version 1 source code

It’s becoming a fashion lately to release the source code of older but legendary commercial products to the public. Now Adobe decided to gift the source code of their flagship product Photoshop in it’s first version from 1990 to the Computer History Museum.


“That first version of Photoshop was written primarily in Pascal for the Apple Macintosh, with some machine language for the underlying Motorola 68000 microprocessor where execution efficiency was important. It wasn’t the effort of a huge team. Thomas said, “For version 1, I was the only engineer, and for version 2, we had two engineers.” While Thomas worked on the base application program, John wrote many of the image-processing plug-ins.”


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Automated Picture Tank and Gallery for a photographer

Since my wife started working as a photographer on a daily basis the daily routine of getting all the pictures off the camera after a long day filled with photo shootings got her bored quickly.

Since we got some RaspberryPis to spare I gave it a try and created a small script which when the Pi gets powered on automatically copies all contents of the attached SD card to the houses storage server. Easy as Pi(e) – so to speak.


So this is now an automated process for a couple of weeks – she comes home, get’s all batteries to their chargers, drops the sd cards into the reader and poweres on the Pi. After it copied everything successfully the Pi sends an eMail with a summary report of what has been done. So far so good – everything is on our backuped storage server then.

Now the problem was that she often does not immediately starts working on the pictures. But she wants to take a closer look without the need to sit in front of a big monitor – like taking a look at her iPad in the kitchen while drinking coffee.

So what we need was a tool that does this:

  • take a folder (the automated import folder) and get all images in there, order them by day
  • display an overview per day of all pictures taken
  • allow to see the fullsized picture if necessary
  • work on any mobile or stationary device in the household – preferably html5 responsive design gallery
  • it should be fast because commonly over 200 pictures are done per day
  • it should be opensource because – well opensource is great – and probably we would need to tweak things a bit

Since I did not find anything near what we had in mind I sat down this afternoon and wrote a tool myself. It’s opensourced and available for you to play with it. Here’s a short description what it does:

It’s called GalleryServer and basically is an embedded http server which takes all .jpg files from a folder (configurable) and offers you some handy tool urls which respons with JSON data for you to work with. I’ve written a very small html user interface with a bit of javascript (using the great html5 kickstart) that allows you to see all available days and get a nice thumbnail overview of each day – when you click on it it opens the full-size image in a new window.

It’s pretty fast because it’s not actively resizing the images – instead it’s taking the thumbnail picture from the original jpg file which the camera placed there during storing the picture. It’s got some caching and can be run on any operating system where mono / .net is available – which is probably anything – even the RaspberryPi.

Source 1: my wifes page
Source 2: 99lime html5 kickstart boilerplate
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Security Engineering — The Book

The second edition of the book “Security Engineering” by Ross Anderson is available as a full download. It’s quite a reference and a must-read for anybody with an interest in security (which for example all developers should have).

“When I wrote the first edition, we put the chapters online free after four years and found that this boosted sales of the paper edition. People would find a useful chapter online and then buy the book to have it as a reference. Wiley and I agreed to do the same with the second edition, and now, four years after publication, I am putting all the chapters online for free. Enjoy them – and I hope you’ll buy the paper version to have as a conveient shelf reference.”

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a good source of all things javascript libraries

Choosing the right javascript library is one of the key elements to create a good prototype in very short times – productive applications even. If you want to get new impressions, hints and links to those javascript libraries that will render your next project a success look no further:

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You shall not interrupt a programmer

A programmer is likely to get just one uninterrupted 2-hour session in a day” is one of the statements this great blog article makes on the matter of interruption of professionals while they do their hard work.

It’s an important thing to understand how that idea to code conversion thing happens. For anyone without that experience: Think of it like being very very concentrated and juggling things. When you get abstracted it’s very likely that you drop something. In the worst case you never even get something to juggle…

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I know what you did last night: the commit logs from last night.

If you can stand a little bit of cursing and bad words and if you’re a developer. You should give this site a visit. The commit logs from last night speak for themselves:

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an ode to the beauty of code by the example of the source code of Doom 3

It’s been a habbit to ID software to release the source code of their previous games and game engines as open source when time is due. That’s what happened with Doom 3 as well. Since beautiful code appears to a lot of developers it’s just a logical step to analyse the Doom 3 source code with the beauty-aspects in mind.

Now there are two very good examples of such analysis.

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my home is my castle – CastleOS: the home automation operating system

And once again some smart people put their heads together and came up with something that will revolutionize your world. Well it’s ‘just’ home automation but indeed it looks very very promising. Especially the human-machine interface through speech recognition. First of all let’s start with a short introductory video:

“CastleOS is an integrated software suite for controlling the automation equipment in your home – an operating system for your castle, if you will. The first piece of the suite is what we call the “Core Service” – it acts as the central controller for the whole system. This runs on any relatively recent Windows computer (or more specifically, the computer that has an Insteon PLM or USB stick plugged in to it), and creates a network connection to both your home automation devices, and the second piece of the integrated suite – the remote access apps like the HTML5 app, Kinect voice control app, and future Android/iOS apps.” (from the CastleOS page)

So it’s said to be an all-in-one system that controls power-outlets and devices through it’s core service and offering the option to add Kinect based speech recognition to say things like “Computer, Lights!”.

Unfortunately it comes with quite high and hard requirements when it comes to hardware it’s compatible with. A kinect possible exists in your household but I doubt that you got the Insteon hardware to control out devices with.

That seems to be the main problem of all current home automation solutions – you just have to have the according hardware to use them. It’s not quite possible to use anything and everything in a standardized way. Maybe it’s time to have a “home plug’n’play” specification set-up for all hard- and software vendors to follow?

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I will be speaking at Open Source Data Center conference 2013

I plan to speak at a couple of conferences this year – first in the line will be the Open Source Data Center conference in Nuremberg.

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“The Open Source Data Center Conference, with a changing focus from year to year, offers you the unique possibility to meet international OS-experts, to benefit from their comprehensive experience and to gain the latest know-how for the daily practice. The conference is especially adapted to experienced administrators and architects.”

The topic I will be talking about (in german though) is our fully virtualized data center testing environment at Rakuten Germany.

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When you want to change things from “testing in production” to “testing in a test environment” it’s usually a very hard way to go. In this case we chose the way to virtualize whatever service was in the datacenter, with all the same configurations and even network settings. We called that “Ignition” and it allows us to test almost any aspect of our production environment without interfereing with it. My talk will cover the thoughts and technologies behind that.

I also want to stress the fact that there are a lot more interesting talks than mine. Go to the OSDC 2013 homepage and find out for yourself.

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h.a.c.s. html5 user interface re-implemented

Slow is the right word to describe my html and javascript learning-by-doing progress right now. I have chosen the h.a.c.s. user interface as a valid project to learn html and javascript up to a point where I can start to write useable websites with it. The h.a.c.s. ui seemed to be a good choice because it’s at the moment only used by my family and they are a bunch of battle-proven beta testers.

So first a small video to get an idea what I am implementing right now:

So all you can see is SVG and HTML rendered stuff – made with the help of awesome javascript libraries, as there are:

  • jQuery
    • for the basic javascript coverage
  • Raphaël
    • to draw svg in a human-controllable
  • JustGage
    • to draw those nice gauges
  • OdoMeter
    • an animated HTML5 canvas odometer

I plan to add a lot more – like for swiping gestures. So this will be – just like h.a.c.s – a continuous project. Since I switched to OS X entirely at home I use the great Coda2 to write and debug the code. It helps a lot to have two browser set-up because for some reason I still not feel that well with the WebKit Web Inspector.

Bildschirmfoto 2013-01-06 um 20.47.22

Another great feature of Coda2 is the AirPreview – which means it will preview your current page in the editor on an iOS device running DietCoda – oh how I love those automations.

So I reached the first goal set for myself for the user interface: It’s doing the things the old UI did and it’s maintainable in addition. I am still struggling with javascript here and there – mainly because the debugging and tracing is oh-so-difficult (or I am to slow understanding).

If you got any recommendation for a javascript editor that can handle multiple includes and debugging (step-by-step, …) and good tracing for events please comment!

Source 1: jQuery
Source 2: Raphaël
Source 3: JustGage
Source 4: OdoMeter

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Every year between Christmas and New Years the hackers of the (mostly european) world gather for the Chaos Communication Congress. This year for the 29th time. The 29c3 takes place where it all started – in Hamburg. This years subtitle is:

Bildschirmfoto 2012-12-25 um 22.14.48

Since the reports are already in that the fairydust has landed successfully in Hamburg there’s even a proof picture for it:


Since FeM is already preparing it will be great to ‘attend’ the congress via live streams of all lectures.

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know your numbers!

Wikipedia describes latency this way:

“Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. In communications, the lower limit of latency is determined by the medium being used for communications. In reliable two-way communication systems, latency limits the maximum rate that information can be transmitted, as there is often a limit on the amount of information that is “in-flight” at any one moment. In the field of human-machine interaction, perceptible latency has a strong effect on user satisfaction and usability.” (Wikipedia)

Given that it’s quite important for any developer to know his numbers. Since latency has a huge impact on how software should be architected it’s important to keep that in mind:


Bildschirmfoto 2012-12-25 um 21.28.20



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Build a Brain – SPAUN

SPAUN or Semantic Pointer Architecture Unified Network is a promising next step in the pursuit to simulate a human brain. Built upon the Nengo Neural Simulator scientists at the University in Waterloo/Ontario were able to report on their first break-through results.

In 2013 there will be a book from Oxford University press called ‘How to build a brain’ which will describe in depth what made the astonishing results possible.

But what are the results?

Well that looks like number recognition. In fact that’s what it is. SPAUN – that’s how the scientists refer to their frankenstein-brain – is capable of solving 8 different tasks now. One of them is number recognition. There are videos of all 8 tasks being performed.

The Semantic Pointers are named after the pointers usually common in computer science:

“Higher-level cognitive functions in biological systems are made possible by semantic pointers. Semantic pointers are neural representations that carry partial semantic content and are composable into the representational structures necessary to support complex cognition.

The term ‘semantic pointer’ was chosen because the representations in the architecture are like ‘pointers’ in computer science (insofar as they can be ‘dereferenced’ to access large amounts of information which they do not directly carry). However, they are ‘semantic’ (unlike pointers in computer science) because these representations capture relations in a semantic vector space in virtue of their distances to one another, as typically envisaged by connectionists. “

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What happened to: realtime Radiosity lighting

Back in 2006 I wrote about a new technology which the also new company Geomerics was demoeing.

Back in 2006 everything was just a demo. Now it seems that Geomerics found some very well known customers and without noticing a lot of the current generation games graphics beauty comes from the capabilities real time radiosity lighting is adding to the graphics.

“Geomerics delivers cutting-edge graphics technology to customers in the games and entertainment industries. Geomerics’ Enlighten technology is behind the lighting in best-selling titles including Battlefield 3, Need for Speed: The Run, Eve Online and Quantum Conundrum. Enlighten has been licensed by many of the top developers in the industry, including EA DICE, EA Bioware, THQ, Take 2 and Square Enix.” (Source)

There even is a more updated version of the demo video:

Source 1: real time radiosity lighting article from 2006
Source 2: Geomerics Presentations
Source 3: More Geomerics Media

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practical filesystem design

In November 1998 there was a book released about file system design taking the Be File System as the central example.

“This is the new guide to the design and implementation of file systems in general, and the Be File System (BFS) in particular. This book covers all topics related to file systems, going into considerable depth where traditional operating systems books often stop. Advanced topics are covered in detail such as journaling, attributes, indexing and query processing. Built from scratch as a modern 64 bit, journaled file system, BFS is the primary file system for the Be Operating System (BeOS), which was designed for high performance multimedia applications.

You do not have to be a kernel architect or file system engineer to use Practical File System Design. Neither do you have to be a BeOS developer or user. Only basic knowledge of C is required. If you have ever wondered about how file systems work, how to implement one, or want to learn more about the Be File System, this book is all you will need.”

If you’re interested in the matter I definitely recommend reading it – it’s available for free in PDF format and will help to understand what those file system patterns are all about – even in terms of things we still haven’t gotten from our ‘modern filesystems’ today.

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second Tokyo Trip 2012 – Rakuten Technology Conference 2012

This October I had the pleasure to fly to Tokyo for the second time in 2012.

The development unit of Rakuten Japan was hosting the 7th Rakuten Technology Conference in Rakuten Tower 1 in Tokyo.

The schedule was packed with up to 6 tracks in parallel. From research to grass-roots-development a lot of interesting topics.

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Source 2: Recorded Lectures

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open source audio codecs getting better

Some weeks ago I heard about a new audio codec which is being developed as open source – very similar to vorbis – the previous open source approach to audio codecs.

This time it seems that they’ve got some standardization into the play so it might be more successful than vorbis was.

“Opus is a totally open, royalty-free, highly versatile audio codec. Opus is unmatched for interactive speech and music transmission over the Internet, but also intended for storage and streaming applications. It is standardized by the Internet Engineering Task Force (IETF) as RFC 6716 which incorporated technology from Skype’s SILK codec and Xiph.Org’s CELT codec.”

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Learn to code

Knowing how to deal with those personal computers is getting more important by the day. Not everybody needs to know how to write code – but since writing code and making those machines do what you want them to do isn’t as hard as it used to be it’s worth the try!

On the mission to learn to code this page is probably very interesting for anyone wanting to learn:

Source 1:!/exercises/0

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generate C# classes from JSON data

It’s a common use case: you’ve got some JSON formatted data and you want to interface with it using your favourite programming language C#. You can write the appropriate classes yourself, or you could use the fabulous json2csharp helper page.

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Entwickler in Hamburg – die Developer Conference 2012 in Hamburg

Der Freitag der vergangenen Woche begann sehr sehr früh. Es ging nach Nürnberg um den Flug nach Hamburg zu erwischen. Erstaunlich wie günstig die heutzutage sind: der Flug nach Hamburg (50 Minuten in der Luft) sollte nur 10 Euro teurer als die Zugfahrt zurück (4 Stunden auf Schienen) sein…

Jedenfalls war es ein schön kurzer Flug und schwupps stand ich vor der Otto Versand Zentrale in Hamburg… Es war Zeit für die…

… Developer Conference Hamburg 2012.

Es war meine erste DevCon-HH und dementsprechend kann ich keine Vergleiche zum letzten Jahr ziehen. Die Räumlichkeiten – direkt bei Otto – waren jedenfalls sehr ordentlich aufgebaut, alles sehr bequem. Kurze Wege zwischen Kaffee und Vortragsstuhl. Die 2 der Vortragssäle waren leider nur über den Hauptsaal zu erreichen. Was ein-zweimal dazu führte dass Vortrage in den kleineren Sälen bereits beendet waren und die Menschenmengen durch den Hauptsaal Richtung Kaffee strömten während die Zuhörer im Hauptsaal noch versuchten zuzuhören. Hier mal im Bild erklärt: Rechts der große Hauptsaal und Links ein kleinerer Vortragssaal. Ich stand beim fotografieren direkt im Türrahmen.

Es ging für mich mit zwei sehr guten und interessanten Vorträgen los. Die Keynote des ersten Tages gibt es mittlerweile auch, wie es sich gehört, auf Slideshare:

Insgesamt war die Qualität der Vorträge sehr hoch. Ich fand die Mischung zwischen harten und soften Themen rund um die Software-Entwicklung mehr als gelungen und sicherlich werde ich versuchen nächstes Jahr wieder zu kommen.


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ELV MAX! Cube progress

I’ve just pushed a commit to the repository which finalizes my current effort in getting data out of the ELV MAX! Cube. With this sourcecode you should be able to get the following information out of your ELV MAX! Cube:

  • a list of all configured rooms
  • a list of all devices in those rooms
  • Thermostat and ShutterContacts have all their flags with them (like Battery Status, Open/Closes, Mode (auto, manual,…))

That brings me one step further to the integration of the ELV MAX! Cube into h.a.c.s. – next weekend probably 🙂

p.s.: I’ve already ordered more thermostat and shuttercontact sensors.

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a javascript / html live-preview editor in your browser

This whole web developing thing is getting somewhere. Take a look at that great implementation of a html / javascript editor with built-in live preview. It got syntax highlighting and all and best of all: it runs directly in your browser. You don’t have to install anything.

Some more information directly from the readme file:

JS Bin is a webapp specifically designed to help JavaScript and CSS folk test snippets of code, within some context, and debug the code collaboratively.

JS Bin allows you to edit and test JavaScript and HTML (reloading the URL also maintains the state of your code – new tabs doesn’t). Once you’re happy you can save, and send the URL to a peer for review or help. They can then make further changes saving anew if required.

The original idea spawned from a conversation with another developer in trying to help him debug an Ajax issue. The original aim was to build it using Google’s app engine, but in the end, it was John Resig‘s Learning app that inspired me to build the whole solution in JavaScript with liberal dashes of jQuery and a tiny bit of LAMP for the saving process.

Version 1 of JS Bin took me the best part of 4 hours to develop, but version 2, this version, has been rewritten from the ground up and is completely open source.”

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Mirror, Mirror on the wall

There are many things which are underestimated when team leads think about their team and possible actions to drive progress.

One of those things is that a team needs information to maintain and gain velocity. You cannot expect everyone to know just out of the blue what is important and in which direction everything is moving. To let everyone know and to develop that direction it’s important to share information as much as possible. It’s important to give everyone access to the information necessary to make a better job.

That’s why we had a build monitor at sones. We had a tool that displayed the current status of our build servers to all developers. Everytime someone committed a change, those build servers got this commit, built it and tested it with automated tests. The status of that could be seen by all developers as things happened.

So within seconds everyone could see if his commit did break something. Even better: Everyone could see. Everyone cared that the build needed to be working, that tests needed to pass. It was everyones job to do the housekeeping. When we switched from Team Foundation Server to GIT and Jenkins this status display needed to be replaced – you could immediately tell that things went from good to not-so-good in terms of build stability and automated testing.

Today I had the opportunity to take a tour of the Thomann logistics center. Standing in the support department I had this in front of me:

There were like 6 big status screens displaying incoming call status of the day, sales figures and other statistics important to those who work there. It’s a very important and integrated way to keep information flowing.

Since I am with Rakuten I thought about having a new status board set-up for my team. Something that might be inspired by the awesome status board which panic has built:

Since in addition to sones there are a lot of more things to track and handle (code, deployment, operations, overall numbers) I think such a status board will be of invaluable worth for the team.

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Adventures in e-Commerce and technology

Oh dear. I just thought about the fact that I never really announced or talked about the fact that I changed my employee and moved to a (old) new place.

Yes that’s right, I am not with sones anymore. I am since January 1st the CTO of Rakuten Germany. When I signed the contract the company was called Tradoria – one of the first big projects I had the opportunity to work on was the so called brandchange.

A humongeous japanese based company called Rakuten bought Tradoria in the middle of 2011 and after half a year it was time to switch the brand.

As you can imagine these were busy weeks since January 1st. I had to digest a lot of existing technology and products. I met and got to know a lot of interesting people – first and foremost a great team of developers that went through almost all imagineable pains and parties to come up with a marketplace and shop system that is a perfect base for take-off.

A short word on the business-model of Rakuten – If you’re a merchant you gotta love it: Think of Rakuten as a full service provider for a merchant and customer. You as a Rakuten merchant get all the frontend and backend bliss to present and manage your products and orders. Rakuten takes care of all the nasty bits and pieces like hosting, development, telephone orders, invoicing, payment. The only thing that you as a Rakuten merchant need to do is to put in great products, gather orders and send out packages. Since Rakuten isn’t selling products on it’s own it won’t be competing with the merchants like other marketplace providers do these days.

On top of that Rakuten cares for the merchant and the customer. Just a week after that successful brandchange I attended (and spoke) at the Tradoria Live! 2012. That’s basically the merchant get-together. This year over 500 people attended this one-day conference. Think of it as a hands-on conference with features, plans, summaries of the last year and the upcoming one – every merchant is invited to come and talk to the people in person that work hard everyday to make the marketplace and shop system better.

click on it to see it big

Just 24 hours later standing on that stage I found myself here:


Yep. That’s Tokyo (東京). After a very long flight we had the chance to attend a all-embracing tokyo tour before the meetings and talks would start for our team. It was an awesome and exhausting week – just about 120 hours later I was back in Germany – I must have slept for two days 🙂

Back in germany I had a lot of stuff to learn and work through. We had already moved to a wonderful house near Bamberg – it was pretty much big luck to find it. It’s actually ridiculously huge for a couple and two cats but we love it. Imagine the contrast: moving from an apartment next to a four-lane city street to the countryside just a 15 minute drive away from work with philosophical quietness all around.

Now after about half a year I am well into the process. I met a lot of high profile techies and things seem to take up speed in regards of teamplay in germany and with all the other countries. It’s a bliss to work for a group of companies that actually go through a lot of transitions while transforming from start-ups to an enterprise.

Ready for a family picture? Ready. Steady. Go!

That’s all Rakuten – that’s all on one mission: Shopping is entertainment! Empower the merchants!

Beside all that I even started to learn japanese. ただいま  🙂

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first conference for about a year: Berlin Buzzwords 2012

It’s been a while since I attended a technology conference. But it’s going to change. This week I attended the Berlin Buzzword 2012 conference in Berlin.

Search.Store.Scale is the headline under which this awesome conference takes place and after a very slow start there were a lot of great talks about current technologies regarding databases, data processing and storage. From great overviews to some very in-depth talks… like the one called “Searching Japanese with Lucene and Solr”. Since I am currently in the process of getting to know the japanese language better this talk in particular had interesting insights into how to handle the japanese language. Very impressive and a bit frightening how complicated language processing can be.

And out gets something like this:

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