Daniel Kirstenpfad – Page 12 – schrankmonster blog

bringing the thinclient back

Posted on March 5, 2019March 2, 2019 by Daniel Kirstenpfad

I had to solve a problem. The problem was that I did not wanted to have the exact same session and screen shared across different work places/locations simultaneously. From looking at the same screen from a different floor to have the option to just walk over to the lab-desk solder some circuits together and have the very same documents opened already and set on the screens over there.

One option was to use a tablet or notebook and carry it around. But this would not solve the need to have the screen content displayed on several screens simultaneously.

Also I did not want to rely on the computing power of a notebook / tablet alone. Of course those would get more powerful over time. But each step would mean I would have to purchase a new one.

Then in a move of desperation I remembered the “old days” when ThinClients used to be the new-kid in town. And then I tried something:

I just recently had moved all house server infrastructure over to Linux and Docker. So what would keep me from utilizing the computing power of that one beefy server in the basement to host all of my desktop needs?

It turns out: Nothing really. Docker is well prepared to host desktop environments. With a bit of tweaking and TigerVNC Xvnc I was able to pre-configure the most current Ubuntu to start my preferred Mate desktop environment in a container and expose it through VNC.

If you wanted to replicate this I would recommend this repository as a starting point.

Even better I found that the RaspberryPi single board computers come with a free pre-licensed and accelerated version of RealVNC.

So I took one of those RaspberryPis, booted up the Raspbian Desktop lite and connected to the dockers VNC port. It all worked just like that.

this is the RaspberryPi client with the windowed docker container VNC session

The screenshot above holds an additional information for you. I wanted sound! Video works smooth up to a certain size of the moving video – after all those RaspberryPis only come with sub Gbit/s wired networking. But to get sound working I had to add some additional steps.

First on the RaspberryPI that you want to output the sound to the speakers you need to install and set-up pulseaudio + paprefs. When you configure it to accept audio over the network you can then configure the client to do so.

In the docker container a simple command would then redirect all audio to the network:

pax11publish -e -S thinclient

Just replace “thinclient” with the ip or hostname of your RaspberryPI. After a restart Chrome started to play audio across the network through the speakers of the ThinClient.

Now all my screens got those RaspberryPIs attached to them and with Docker I can even run as many desktop environments in parallel as I wish. And because VNC does not care about how many connections there are made to one session it means that I can have all workplaces across the house connected to the same screen seeing the same content at the same time.

And yes: The UI and overall feel is silky smooth. And since VNC adapts to some extend to the available bandwidth by changing the quality of the image even across the internet the VNC sessions are very much useable. Given that there’s only 1 port for video and 1 port for audio it’s even possible to tunnel those sessions across to anywhere you might need them.

work and walk

Posted on March 4, 2019March 2, 2019 by Daniel Kirstenpfad

Working in the IT industry requires us to spend copious amounts of time focused on our screens mostly sitting at our desks. But this does not have to be that way.

For me sitting down for long times creates a lot of unwanted effects and essentially leads to me not being able to focus anymore properly.

In 2015 my wife and I attacked that “health problem” as a team. And in the 12 months until 2016 we both lost 120 kg / 260lbs added up together in body weight and completely changed the way we deal with food and sport.

With that I also changed the way I work. Sitting down was from now on the exception.

Coincident with this lifestyle change my then-employer Rakuten rolled out it’s then new workplace concept and everyone got great electric stand-up desks that allowed you to change the height up and down effortlessly.

When I started with SIEMENS of course their workplace concept included standing desks as well!

For those times I am working from home one of the desks is equipped with a standing desk with an additional twist.

So this desk let’s you work while standing. But it also allows you to walk while you work. You can set the speed from 0 to 6.4 km/h.

Given a good headset I personally can attend conference calls without anyone noticing I am walking with about 4 km/h paces.

When I am spending a whole day working from this desk it is not uncommon to accumulate 25-40 km of total distance without really noticing it while doing so. Of course: later the day you’ll feel 40km in one way or the other

monthly distance … something between 50 and 350km … only 50km at the desk when walking outside is possible.

It took a bit of getting used to as your feet are doing something entirely different from what the rest of the body is doing. But at least for me it started to feel natural very quickly.

I’ve put two curved 24″ monitors onto it and aside from the docking ports for a company notebook I am using thinclients to get my usual work machines screens teleported there. There’s a bit of a media set-up as well as sometimes I am using one of the screens for watching videos.

For those now interested in the purchase of such a great walking desk: I can only recommend doing so! But be aware of some thoughts:

There are not a lot of vendors of such appliances. And those vendors are not selling a lot of them. This means: be ready for a € 1000+ purchase and be ready to shell out some good money on extended warranties.

My first desk + treadmill was replaced 3 times before. It was LifeSpans first generation of treadmill desks and it just kept exploding. I actually had glowing sparks of fire spitting out of the first generation treadmill.

I’ve returned it for no money loss and waited for the second generation. This current, second generation of LifeSpan treadmill desks is really doing it for me for longer than the first generation ever had without breaking. Looking at the use of the device I would see it as a purchase over 5 years. After 5 years of actual and consistent use I wouldn’t be overly annoyed if the mechanical parts of the appliance would stop working. I am not expecting such a device to live much longer anyhow.

Energy consumption wise it’s quite impressive how much energy this thing consumes. I wasn’t quite expecting those levels. So here’s for you to know:

So just around 500 Watts when in use. The 65W base load is the monitors and computers on top.

did you know: Linus Torvalds used to use a first generation model – the one that broke on me many times

I can only recommend to try something like this out. Unfortunately it’s quite hard to find a place to try it out. At least I was not able to try before buy.

But then again I could answer your questions if you had any.

Digital assistant language teacher

Posted on March 3, 2019 by Daniel Kirstenpfad

Since a couple of months we are trying harder to learn a foreign language.

And as we excepted it is very hard to get a proper grasp on speaking the language. Especially since it is a very different language to our mother tongue.

And while comfortably interacting with digital assistants around the house every day in english and german the thought came up: why don’t these digital assistants help with foreign language listening and speaking training?

I mean Google Assistant answers questions in the language you have asked them. Siri and Alexa need to know upfront in which language you are going to ask questions. But at least Alexa can translate between languages…

But with all seriousness: Why do we not already have the obvious killer feature delivered? Everyone could already have a personal language training partner…

“kachung” + shutter sound

Posted on March 3, 2019 by Daniel Kirstenpfad

When you take a picture with an iPhone these days it does generate haptic feedback – a “kachung” you can feel. And a shutter sound.

Thankfully the shutter sound can be disabled in many countries. I know it can’t be disabled on iPhones sold in Japan. Which kept me from buying mine in Tokyo. Even when you switch the regions to Europe / Germany it’ll still produce the shutter sound.

Anyway: With my iPhone, which was purchased in Germany, I can disable the shutter sound. But it won’t disable the haptic “kachung”.

look ma! no mirror! (yes this is an iPhone 6)

It’s interesting that Apple added this vibration to the activity of taking a picture. Other camera manufactures go out of their way to decouple as much vibration as possible even to the extend that they will open the shutter and mirror in their DSLRs before actually making the picture – just so that the vibration of the mirror movement and shutter isn’t inducing vibrations to the act of taking the picture.

With mirror less cameras that vibration is gone. But now introduced back again?

Am I the only one finding this strange?

testing video

Posted on March 2, 2019March 2, 2019 by Daniel Kirstenpfad

One thing I cannot do without linking to external sources or having control over the content storage is to have videos here on the pages.

There are a couple of options to achieve this and I am evaluating some of them right now. The goal is very clear:

no external links
no external resources embedded or included
720p/1080p/2160p quality levels, ideally with bandwidth scaling

So let’s see some options tried out:

720p

1080p

2160p

wireless mesh network

Posted on March 2, 2019March 1, 2019 by Daniel Kirstenpfad

Since AVM has started to offer wireless mesh network capabilities in their products through software updates I started to roll it out in our house.

Wireless mesh networks often consist of mesh clients, mesh routers and gateways. Mobility of nodes is less frequent. If nodes constantly or frequently move, the mesh spends more time updating routes than delivering data. In a wireless mesh network, topology tends to be more static, so that routes computation can converge and delivery of data to their destinations can occur. Hence, this is a low-mobility centralized form of wireless ad hoc network. Also, because it sometimes relies on static nodes to act as gateways, it is not a truly all-wireless ad hoc network.
Wikipedia

With the rather complex physical network structure and above-average number of wireless and wired clients the task wasn’t an easy one.

To give an impression of what is there right now:

So there’s a bit of almost everything. There’s wired connections (1Gbit to most places) and there is wireless connections. There are 5 access points overall of which 4 are just mesh repeaters coordinated by the Fritz!Box mesh-master.

There’s also powerline used for some of the more distant rooms of the mansion. All in all there are 4 powerline connections all of them are above 100 Mbit/s and one even is used for video streaming.

All is managed by a central Fritz!Box and all is well.

Like without issues. Even interesting spanning-tree implementations like from SONOS are being properly routed and have always worked without issues.

The only other-than-default configuration I had made to the Fritz!Box is that all well-known devices have set their v4 IPs to static so they are not frequently switching around the place.

How do I know it works? After enabling the Mesh things started working that have not worked before. Before the Mesh set-up I had several accesspoints independently from each other on the same SSID. Which would lead to hard connection drops if you walked between them. Roaming did not work.

With mesh enabled I’ve not seen this behavior anymore. All is stable even when I move actively between all floors and rooms.

Apple Health challenges are broken

Posted on March 1, 2019 by Daniel Kirstenpfad

We are using Apples smartwatch to measure some health stats during our workouts. And Apple Watch is doing a great job at that.

With all that polish one would expect better from what Apple has to offer in the software department…

Apple Watch has monthly challenges that get automatically generated from previous measurements. But seeing that an already much above average activities number would have to be doubled to complete the challenge is absurd. To a degree where challenges are arguably health risks…

ssl on;

Posted on February 28, 2019February 28, 2019 by Daniel Kirstenpfad

I’ve recently written about the privacy and data security state of this blog and starting today all content is being provided encrypted.

Bless the wonderful Let’s Encrypt project!

a scientific paper a day

Posted on February 27, 2019February 28, 2019 by Daniel Kirstenpfad

I am long-time subscriber to a service that is delivering a curated choice of scientific papers to your inbox every morning.

And even better: On top of the choice and link of the paper you also get a great summary with additional links and hints on the topic.

The Morning Paper: a short summary every weekday of an important, influential, topical or otherwise interesting paper in the field of computer science.
https://blog.acolyer.org/about/

Depending on your specific interests the papers chosen will give you deep insights into certain topics. Recently a lot of AI related topics show up there.

The papers are delivered by eMail, by RSS feed of by just reading the blog.

an afternoon in the park

Posted on February 23, 2019February 23, 2019 by Daniel Kirstenpfad

Living in an UNESCO world heritage city has a lot of advantages. One of them is the amount of nice parks and areas to enjoy the spring sun.

a small island park almost in Bamberg / Germany
(OpenStreetmap)

We’ve spent the afternoon walking around and taking some pictures.

celebrate the discordian holyday: Chaoflux

Posted on February 19, 2019February 17, 2019 by Daniel Kirstenpfad

allow me to explain by quoting wikipedia:

Dicordianism is a paradigm based upon the book Principia Discordia, written by Greg Hill with Kerry Wendell Thornley in 1963, the two working under the pseudonyms Malaclypse the Younger and Omar Khayyam Ravenhurst.
According to its primary historian, Adam Gorightly, Discordianism was founded as a parody religion. Many outside observers still regard Discordianism as a parody religion, although some of its adherents may utilize it as a legitimate religion or as a metaphor for a governing philosophy.

The Principia Discordia, if read literally, encourages the worship of Eris, known in Latin as Discordia, the goddess of disorder, or archetypes and ideals associated with her. Depending on the version of Discordianism, Eris might be considered the goddess exclusively of disorder or the goddess of disorder and chaos.
Both views are supported by the Principia Discordia. The Principia Discordia holds three core principles: the Aneristic (order), the Eristic (disorder), and the notion that both are mere illusions.
Due to these principles, a Discordian believes there is no distinction between disorder and chaos, since the only difference between the two is that one refers to ‘order’.
This is likely a major reason for the inconsistency in the wording. An argument presented by the text is that it is only by rejecting these principles that you can truly perceive reality as it is, chaos.
wikipedia

And given that information you can expect a discordian calendar to exist. This calendar defines years (YOLD = year of our lady of discord) and seasons and days. And holydays:

Chaosflux is a Holyday of the season of Chaos. It is celebrated on Chaos 50 (Discordian calendar) or February 19 (Gregorian calendar).
Very little is known about this holyday. What we do know is pretty much made up as we go along.
discordia wikia GFDL

So now back to the holyday itself. How would you celebrate such a distinguished day?

I will use the services of theuselessweb.com to click 5 times on their most interesting button and then meditate on what comes up:

How to get me to actively avoid your products

Posted on February 17, 2019February 28, 2019 by Daniel Kirstenpfad

It is a simple one step process: shove unasked advertising in my face. Bonus points for loud full blast audio right of the start.

If I ever see unasked advertising that tried to be sneaky or not do sneaky I am going to block it without noticing from whom or for what it was.

But when it’s shown so often and is so intrusive that I take note of your brand. That brand is not considered for future business anymore.

That is especially for services where I am the product paying with my data.

how to find out who needs to clear out the dishwasher

Posted on February 16, 2019February 28, 2019 by Daniel Kirstenpfad

We use the term “smart home” lightly these days. It has become a term of marketing and phantastic stories.

Considering how readily available lots of different sensors, actors and personal-assistants are these days one would think that most people would start to expect more from the marketing “smart-home”.

I believe that the smart is to be found in the small and simple. There are a lot of small things that actually make something feel smart without it actually being smart about anything.

Being smart is something not achieved yet – not even by a far stretch of the sense of the word. So let’s put that to the sides of the discussion for now and move a simple thing in the middle of this article.

Have you ever had an argument about who should or should have cleared out the dishwasher after it’s finished?
We had.

So we outsourced the discussion and decision to a 3rd party. We made our house understand when the dishwasher starts and ends it’s task. And made it flip a coin.

There was already a power consumption monitoring in place for the dishwasher. Adding a hysteresis over that monitoring would yield a simple “starts running” / “stops running” state of the dishwasher.

Pictured above is said power consumption.

When the values enter the red area in the graph the dishwasher is considered to be running.
When it leaves that area the dishwasher is considered finished/not running

Now adding a bit of random coin-tossing by the computer and each time when the dishwasher is detected to have started work a message is sent out depending on the result of the coin-toss.

That message is published and automatically displayed on all active displays in the house (TVs/…) and sent as push notifications to all members that need to be informed of this conclusive and important decision.

In short:

Everyone gets a push notification who is going to clear out the dishwasher based upon a coin-toss by a computer every time the dishwasher starts.

The base of all of this is a Node-RED flow that that uses the power consumption MQTT messages as an input and outputs back to MQTT as well as pushes out the push notifications to phones, screens and watches.

Additionally it creates a calendar entry with the start-finish time of the dishwasher run as well as the total energy consumption for this run.

The flow works like this: on the right the message enters the flow from MQTT. The message itself contains just the value of the power consumed at this very moment. In this case consumed the dishwasher.

The power consumption is updated regularly, every couple of seconds this way. So every couple of seconds this flow runs and gets an updated value of

Next a hysteresis is applied. In simple terms this means: when the value goes above a certain threshold the dishwasher is considered to be running. When it goes below a certain threshold then it is considered finished.

When the dishwasher changed it’s state to “running” the flow will generate a random number between 0 and 1. This give a 50:50 chance for either Steffi or Daniel be the chosen one to clear out the dishwasher for this run. This message is sent out as push notification to all phones, watches and TVs.

When the dishwasher finishes it’s run the total energy consumption is taken and sent out as the “I am done message”. Also this information is added to the calendar. Voilá.

A calendar? Why a calendar you may ask. Oh well there are several reasons. Think of calendars as another way to interact with the house. All sorts of things happen on a timeline. A calendar is only a visual aid to interact with timelines.

May it be a home appliance running and motion being sensed for your home alarm system. All of that can be displayed in a calendar and thus automatically sync to all your devices capable to display this calendar.

And if you start adding entries to a calendar that the house uses to know what to do next… how about putting light on-off times into an actual calendar right on your phone instead of a complicated browser user interface like many of those marketing smart-homes want us to use?

Never confuse wisdom with luck.
44th Rule of Acquisition / Ferengi

data security and privacy on this website

Posted on February 16, 2019February 28, 2019 by Daniel Kirstenpfad

As of early 2019 I’ve started to bring back my content output stream to this website/weblog.

So far I am feeling quite confident publishing content here and even with changing legislation I am doing my best to provide an as good as possible experience to each visitor.

As of End-of-February 2018 this blog is being provided securly encrypted with SSL certificates from Let’s Encrypt.

So security is one thing. Data privacy and safety another.

Apart from the commenting and searching there’s no functionality provided to enter/store data.

comments

When you enter a comment the assumption is that this is your call for consent. Your comment will be stored. With the information you’ve entered and can see on-screen as well as the IP address you’ve used. Akismet then is used to provide Anti-comment-SPAM functionality – so part of this data is transferred over to Akismet for processing. After moderation the comment is visible for everyone under the article you’ve created it.

cookies and browser local storage

No cookies are used or required by the website.

server logfiles

There are no logfiles. No access and no error logs. There is no tracking or analysis. There is no advertisting or monitoring. All I can see is an nginx and php process delivering websites. Your IP address is know to the server for as long as it takes to do his job of delivering the asset you asked for. Nothing gets stored on server side for your read requests.

content loading

No content is loaded from other domains or websites. Everything is hosted on my server. No data is exchanged with externals to bring you this website.

two factor mandatory for apple developers

Posted on February 16, 2019 by Daniel Kirstenpfad

Apple has started to force developers that want to develop and publish on the MacOS and iOS platform to enable two-factor authentication.

Two-factor authentication (also known as 2FA) is a type, or subset, of multi-factor authentication. It is a method of confirming users’ claimed identities by using a combination of two different factors: 1) something they know, 2) something they have, or 3) something they are.
wikipedia

When I just got around enabling it for one of the apple accounts I’ve got there seems to be a much much higher security barrier in place already…

That’s probably some sort of zero-factor no-authentication. I guess. Anyway: Kudos to Apple for finally forcing people to minimum standards. Properly integrating the second factor will make this so much simpler for users. Apples ecosystem solution already is quite well integrated.

Have you switched all your daily used services to two-factor authentication yet?

disaster warning!!! This is just a test.

Posted on February 15, 2019February 15, 2019 by Daniel Kirstenpfad

Apparently yesterday somebody pushed the wrong button. Twice.

Like most countries Germany got a system in place to broadcast out warnings to the public in case of disasters or else.

And it proved to be quite useful in the past when it comes to the occasional storm or heavy snowfall/rain/lightning.

Seeing that they run a test and then again send out an apology to have run a test is puzzling and funny at the same time. Everyone has a “bad hair” day, right?

can your kitchen scale do this trick? – ESP8266+Load Cell+MQTT

Posted on February 12, 2019 by Daniel Kirstenpfad

Ever since we had changed our daily diet we started to weigh everything we eat or cook. Like everything.

Quickly we found that those kitchen scale you can cheaply buy are either not offering the convenience we are looking for or regularly running out of power and need battery replacements.

As we already have all sorts of home automation in place anyway the idea was born to integrate en ESP8266 into two of those cheap scales and – while ripping out most of their electronics – base the new scale functionality on the load cells already in the cheap scale.

So one afternoon in January 2018 I sat down and put all the parts together:

my notes of the wiring… this might be different for your load cells…

After the hardware portion I sat down and programmed the firmware of the ESP8266. The simple idea: It should connect to wifi and to the house MQTT broker.

It would then send it’s measures into a /raw topic as well as receive commands (tare, calibration) over a /cmd topic.

Now the next step was to get the display of the measured weights sorted. The idea for this: write a web application that would connect to the MQTT brokers websocket and receive the stream of measurements. It would then add some additional logic like a “tare” button in the web interface as well as a list of recent measurements that can be stored for later use.

the web app. I am not a web designer – help me if you can! ;-)

An additional automation would be that if the tare button is pressed and the weight is bigger than 10g the weight would automatically be added to the measurements list in the web app – no matter which of the tare buttons where used. The tare button in the web app or the physical button on the actual scale. Very practical!

Here’s a short demo of the logic, the scale and the web app in a video:

You can grab the sourcecode for the Arduino ESP8266 firmware as well as the source code for the web application here.

fonts for your programming needs

Posted on February 12, 2019February 10, 2019 by Daniel Kirstenpfad

We are looking at our screens more and more time of the day and most of that time we are reading or writing text. Text needs to look pretty for our eyes not to get sore – apart from the obvious “being able to tell what letter that is” there is a big portion of personal taste and preference when it comes to the choice of the font.

Most of the texts I am writing benefit from monospaced fonts.

This blog celebrates monospaced fonts for programming.
So many fonts have popped up in recent years.
programmingfonts.org/about

Of course there’s a nice page available that previews the fonts right in your browser:

active noise cancellation does not suck on your eardrums

Posted on February 11, 2019February 10, 2019 by Daniel Kirstenpfad

If you ever traveled on a train or plane with good active noise cancellation headphones you might agree how much more pleasant the trip was with much less noise reaching your ears.

When I tried active noise cancellation for the first time I had that weird sensation as if the pressure around suddenly changed. Like being in a very fast elevator or going for a quick dive. It felt weird but luckily it went away and the aww of joy replaced it. Quietness. Bliss.

Now there seem to be people for whom that feeling won’t go away. They get headaches and cannot stand the feeling when using active noise cancellation.

I’ve never had any explanation to this phenomena – until now. I ran across an article on SoundStage describing that in fact the feeling is not caused by actual changes of pressure but…

According to the engineer, eardrum suck, while it feels like a quick change in pressure, is psychosomatic. “There’s no actual pressure change. It’s caused by a disruption in the balance of sound you’re used to hearing,” he explained.
eardrum suck – the mystery solved

Aha! The brain gets confused by signals reaching your ears that naturally would not exists. Those signals make no sense so the brain tries to make sense of it. And voilá something is sucking your ear drum!

LED projector for your home automation needs

Posted on February 9, 2019February 10, 2019 by Daniel Kirstenpfad

In 2017 Texas Instruments had released a line of cheap industry grade LED projectors meant to be used in production lines and alike:

DLP® LightCrafter Display 2000 is an easy-to-use, plug-and-play evaluation platform for a wide array of ultra-mobile and ultra-portable display applications in consumer, wearables, industrial, medical, and Internet of Things (IoT) markets. The evaluation module (EVM) features the DLP2000 chipset comprised of the DLP2000 .2 nHD DMD, DLPC2607 display controller and DLPA1000 PMIC/LED driver. This EVM comes equipped with a production ready optical engine and processor interface supporting 8/16/24-bit RGB parallel video interface in a small-form factor.
Texas Instruments

And of course this got picked up by the makers. In the hands of people like MickMake who designed an adapter PCB for the RaspberryPi Zero W to the smallest projector available from TI.

After I had learned about the existence of those small projectors I had to get a couple and try for myself. There would be so many immediate and potential applications in our house.

2x DLPLDCR2000EVM with MickMake adapter and RaspberryPi Zero W

After having them delivered I did the first trial with just a breadboard and the Raspberry Pi 3.

The projector module has a native resolution of 640×360 – so not exactly high-pixel-density. And of course if the image is projected bigger the screen-door effect is quite noticeable. Also it’s not the brightest of images depending on the size. For the usual use-cases the brightness is definitely sufficient.

Downsides

too low brightness for large projection size – no daylight projection
low resolution is an issue for text and web content – it is not so much of an issue for moving pictures as you might think. Video playback is well usable.
flimsy optics that you need to set focus manually – works but there is no automatic focus or alike.

Upsides

very low powered – 2.5A/5V USB power supply is sufficient for Pi Zero + Projector on full brightness (30 lumen)
low brightness is not always bad – one of our specific use cases requires an as dim as possible image with fine grain control of thr brightness which this projector has.
extremely small footprint / size allows to integrate this device into places you would not have thought of.
almost fully silent operation – the only moving part that makes a sound is the color wheel inside the DLP module. You have to put your ear right onto it to hear anything.
passive cooling sufficient – even at full brightness an added heat sink is enough to dissipate the heat generated by the LED.

So what are these use cases that require such a projector you ask?

Night status display:

For the last 20+ years I am used to sleep with a “night playlist” running. So far a LED TV was used at the lowest brightness possible. Still it was pretty bright. The projector module allows to dim the brightness down to almost “moon brightness” and also allows to adjust the color balance towards the reds. This means: the perfect night projection is possible! And the power consumption is extremely low. A well watchable lowest brightness red-shifted image also means much lower temperatures on the projector module – it’s crazy how low powered, low temperature.

at 75% brightness (camera did not properly focus…)

Season Window Projection:

Because the projector is small, low-powered and bright enough for back-lit projection we tried and succeeded with a Halloween window projection scene the last season.

It really looks funky from the outside – funky enough to have several people stop in front of the house and point fingers. All that while power consumption was really

House overall status projections:

When projecting information is that cheap and power efficient it really shines when used to display overall status information like house-alarm status, general switch maps, locations of family members and so on. I’ve left those to your imagination as these kind of status displays are more or less giving away a lot of personal information that isn’t well suited for the internet.

Head Up Display esthetics

Posted on February 9, 2019February 9, 2019 by Daniel Kirstenpfad

Many cars these days come with head up displays. These kind of displays are used to make information like the current speed appear “floating” over the street ahead right in your field of vision.

This has the clear advantage that the driver can stay focused on the street rather than looking away from the street and to the speedometer.

As practical as it seems these displays are not easy to build and seemingly not easy to design. Every time I came across one it’s built-in functionalities where limited in a way that I only can assume not a lot of thought had gone into what exactly would the driver like to see and how that would be displayed. There was always so much left to desire.

Apparently the technology behind these HUDs is at a point where it’s quite affordable to start playing with some ideas to retrofit a car with a more personal and likeable version.

So I started to take a look at what is available – smart phones have bright displays and I had never tried to see what happens when you try to utilize them to project information into the windshield. So I tried.

As you can see – bright enough, readable but hazy and not perfectly sharp. The reason is quite simple:

“In the special windshield normally used, the transparent plastic safety material sandwiched in between the two pieces of glass must have a slight and very precise wedge, so that the vehicle operator does not see a HUD double image.”
laserfocusworld

There are some retrofit adhesive film solutions available that claim to help with that. I have not tried any yet. To be honest: to my eye the difference is noticeable but not a deal-breaker.

So I’ve tried apps available. They work. But they do a lot of things different from how I would have expected or done them. They are bearable, but I think it could be done better.

tldr: I started prototyping away and made a list of things that need to be done about the existing HUD applications.

mirrored basic html prototype, not well adjusted, just to play…

Here’s my list of what I want to achieve:

display orientation according to driving direction – I had expected all HUD applications to do this. They know the driving direction. They know how the device is oriented in space. They can tell which direction the windshield is. They know how to correctly turn the screen. They do not do that. None of them.
fonts and numbers – I cannot stand the numbers jumping around when they change up and down
speed steps interpolation – GPS only delivers a speed update every second or so. In this time speed might jump up and down by more than +1. The display has 60 fps and gyros to play with and interpolate… I want smooth number transitions.
have an “eco-meter” – using gyros the HUD would be able to display harsh accelleration and breaking. Maybe display a color-coded bar and whatever is measured is reflected in the bar going left or right…
speed-limit display – apparently this is a huge issue looking at the data availability. There seems to be open-street-map data and options to contribute. Maybe that can be added.
have a non-hud mode – non mirrored to use for example to set speed limits and contribute to OpenStreetMap this way!
automatically switch between HUD and non-HUD mode – because the device knows it’s orientation in space – if you pick it up from the dashboard and look into it, why not automatically switch?
speed zones color coding – change the color of the speed display depending on configurable speed regions. 0-80 is green, 80-130 is yellow, 130-250 is red.
turn display off when car stopped – if there’s nothing displayed or needs to be displayed, for example because the car stopped the display can be turned off completely on it’s own.

Navigation is of limited value as the only way I could think of adding value would be a serious AR solution that uses the whole windshield. Now I’ve got these small low-power projectors around… that get’s me thinking…

What would you want to have in such a HUD in your car?

sakura season forecast

Posted on February 7, 2019February 8, 2019 by Daniel Kirstenpfad

I am visiting Japan for almost 7 years now but I’ve never actually been there when the famous cherry blossom – or sakura – was in full force.

As every year there’s a forecast map for this years season and it gets updated frequently:

First Forecast Issued January 24th
Second Forecast Issued February 7th <- today
Third Forecast Issued February 21st
Fourth Forecast Issued February 28th

picture not showing japanese cherry blossoms

try to read/listen to japanese

Posted on February 4, 2019February 3, 2019 by Daniel Kirstenpfad

I am at the stage of “trying to comprehend” the japanese spoken language.

I’ll be a happy camper if I would understand most of what is being said and could follow daylight normal conversations pointed towards me japanese. Like, you know, when trying to make a purchase or having to ask for that one bit of information.

For this, apart from excessive exposure to the spoken language, I am using some tools to help with reading to a small degree.

For those completely out of the loop:

Japanese has no genetic relationship with Chinese, but it makes extensive use of Chinese characters, or kanji (漢字), in its writing system, and a large portion of its vocabulary is borrowed from Chinese. Along with kanji, the Japanese writing system primarily uses two syllabic scripts, hiragana (ひらがな or 平仮名) and katakana (カタカナ or 片仮名). Latin script is used in a limited fashion, such as for imported acronyms, and the numeral system uses mostly Arabic numerals alongside traditional Chinese numerals.
https://en.wikipedia.org/wiki/Japanese_language

Here’s a list:

language analysis and explanation based on random news

icon this blog

Posted on February 3, 2019 by Daniel Kirstenpfad

I’ve written about the progressive web application functionalities provided by this blog. But I’ve missed to explain in all simplicity what it means for most of you trying to read.

This is where Volker explains in simple terms what to do:

Step 1: Tap this icon in your browser:
(maybe someone can send me an android icon that does this?)

Step 2: Find and tap on “Add to Home Screen”

Enjoy the quick access to this blog.

power consumption after the ssd swap

Posted on February 2, 2019 by Daniel Kirstenpfad

A week after swapping out mechanical hard drives for SSDs it’s time to look at what it meant in the longer run for the power consumption of the server.

Depending on what the server is asked to do – high or low cpu load and so on – the power consumption fluctuates but it’s very visible that the averages are about 15 watt lower at all times. Great!

out with the old, in with the new – house gets ssd upgrade

Posted on January 27, 2019January 27, 2019 by Daniel Kirstenpfad

A week ago I had written about another mechanical hard drive that was about to bite the dust in our houses elaborate set-up.

Not having time for a full-day-of-focus I postponed the upgrade to this saturday. With the agreement of the family as they are suffering through the maintenance period as well.

The upgrade would need cautious preparation in order to be doable in one sitting. And this was also meant to be some sort of disaster-recovery-drill. I would restore the house central docker and service infrastructure from scratch along this.

And this would need to happen:

all services, zfs pools, docker containers, configurations needed to be double checked for full backup – as this would be used to restore all (ZFS snapshots are just the bomb for these things!)
the main central docker server would have to go down
get all hard disks ripped out
SSDs put in and properly configured

get a fresh Ubuntu 18.04 LTS set-up and booting from ZFS on a NVMe SSD (bios update(s)!, secure boot disabling, ahci enabling, m.2 instead of sata express switching…you get the idea)
get the network set-up in order: upgrading from Ubuntu 16.04 to 18.04 means ifupdown networking was replaced by netplan. Hurray! Not.
get docker-ce and docker-compose ready and set-up and all these funky networkings aligned – figure out in this that there are major issues with IPv6 in docker currently.
pull in the small number of still needed mechanical hard disks and import the ZFS pools
start the docker builds from the backup (one script \o/)
start the docker containers in their required order (one script \o/)

Apart from some hardware/bios related issues and the rather unexpected netplan introduction everything went fairly good. It just takes ages to see data copied.

the “heartbeat” is a general term in our house for busy everything is. It’s an artificial value calculated from sensor inputs/s and actions taken and so on. Good indication if there are issues. During the time of maintenance (organge/red) it hasn’t been updated and was stuck at the pre-given value.

Bandwidth was the only real issue with this disaster recovery. All building blocks seemed to fall into place and no unplanned measure had to be taken. The house systems went partially down at around 12:30 and were back up 10 hours later 22:00. Of course non-automated things like internet kept working and all switches were only manual push-buttons. So everything could be done still but with a lot less convenience.

All in all there are more than 40 vital docker container based services that get started one after the other and interconnect to deliver a full house home automation. With the added SSD performance this whole ship is much much more responsive to activities. And hopefully less prone to mechanical defects.

Backup and Disaster-Preparations showed to be practical and working well. There was no beat missed (except sensor measure values during the 10 hours downtime) and no data lost.

Core i3 with 3.7 Ghz and 32 Gbyte RAM is sufficient and tuned for power consumption

What could be done better: It could be much more straight forward when there were less dependencies on external repositories / docker-hub. Almost all issues that came up with containers where from the fact that the maintainers had just a day before introduced something that kept them from spinning up naturally. Bad luck. But that can be helped! There’s now a multi-page disaster-recovery-procedure document that will be used and updated in the future.

Oh and what speeds am I seeing? The promissed 3 Gbyte/s read and write speeds are real. It’s quite impressive to see 4-digit megabyte/s values in iotop frequently.

I almost forgot! During this exercise I had been in the server room less than 30 minutes. But I was on a warm and nice work-desk set-up I am using in the house as much as I can – and I will tell you about it in another article. But the major feature of this work-desk set-up is that it is (a) a standing desk and (b) has a treadmill under it. Yes. Treadmill.

You will get pictures of the set-up in that mentioned article, but since I had spent more than 10 hours walking on saturday doing the disaster recovery I want to give you a glimpse of what such a set-up means:

46 km while doing disaster recovery successfully.

indoor location tracking with ESP32

Posted on January 24, 2019January 23, 2019 by Daniel Kirstenpfad

This project uses the same approach that I took for my ESP32 based indoor location tracking system (by tracking BLE signal strength). But this project came up with an actual user interface – NICE!

“Indoor positioning of a moving iBeacon, using trilateration and three ESP32 development modules. ESP32 modules report all beacons they see, to MQTT topic. Dashboard subscribes to this topic, and shows the location of beacons which are seen by all three stations.”
(https://github.com/jarkko-hautakorpi/iBeacon-indoor-positioning-demo)

hard drive reliability stats 2018

Posted on January 23, 2019January 23, 2019 by Daniel Kirstenpfad

Backblaze is a company that offers cloud storage space and therefore operates a large amount of storage arrays.

In their own words:

As of December 31, 2018, we had 106,919 spinning hard drives.
https://www.backblaze.com/blog/hard-drive-stats-for-2018/

This large amount of spinning disks means that there are also failing drives that stop spinning once every while. Backblaze saw the need to take note about what hard-drive series fails more of less often and started to generate a yearly report on the reliability of these hard drives.

Yesterday they published their report for 2018 – if you got storage requirements or if you are in the market to purchase storage space for your operation – it probably is very helpful to take a look at the report.

Apple Airplay for SONOS (in Docker)

Posted on January 22, 2019January 21, 2019 by Daniel Kirstenpfad

We’ve got a couple of SONOS based multi-room-audio zones in our house and with the newest generation of SONOS speakers you can get Apple Airplay. Fancy!

But the older hardware does not support Apple Airplay due to it’s limiting hardware. This is too bad.

So once again Docker and OpenSource + Reverse-Engineering come to the rescue.

AirConnect is a small but fancy tool that bridges SONOS and Chromecast to Airplay effortlessly. Just start and be done.

It works a treat and all of a sudden all those SONOS zones become Airplay devices.

There is also a nice dockerized version that I am using.

blockchain

Posted on January 21, 2019January 22, 2019 by Daniel Kirstenpfad

I think I’ve found a legitimate application for a blockchain. I think.

waking up to another dying hard disk – upgrade time!

Posted on January 20, 2019January 20, 2019 by Daniel Kirstenpfad

At our house I am running a medium-sized operation when it comes to all the storage and in-house / home-automation needs of the family.

This is done by utilizing several products from QNAP, Synology and a custom built server infrastructure that does most of the heavy-lifting using Docker.

This morning I woke up to an eMail stating that one of the mirrored drives in the machine is reporting read-errors.

Since this drive is part of a larger array of spinning-rust style hard disks just replacing it would work but due to the life-time of those drives I am not particularly interested in more replacing in the very near future. So a more general approach seems right.

63083 lifetime hours = 2628 days = **7.2 years powered up**

You can see what I mean. This drive is old. Very old. And so are its mates. Actually this is the newest drive of another 6 or so 1.5TB and 1TB drives in this array.

Since this redundant array in fact is still quite small and not fully used as most storage intensive non service-related disk space demands have moved to iSCSI and other means it’s not the case anymore that so many disks, so well redundant with so little disk space are needed anymore. Actual current space utilization seems about 20% of the available 2TB volume.

Time for an upgrade! Taking a look in the manual of the mainboard I had replaced 2 years ago I found that this mainboard does have dual NVMe m.2 ports. From which I can boot according to that same manual.

So I thought: Let’s start with replacing the boot drives and the /var/lib docker portions with something fast.

To my surprise Samsung is building 1 TB NVMe M.2 SSDs to a price I expected to be much higher.

Nice! So let me reeport back when this shipped and I can start the re-set-up of the operating system and docker environment. Which by all fairness should be straight forward. I will upgrade from Ubuntu 16.04 LTS to 18.04 LTS in the same step – and the only more complex things I expect to happen is the boot-from-ZFS(on Linux) and iSCSI set-up of the machine.

If you got any tips or best-practice, let me know.

I just have started the catch-up on what happpened in the last 2 years to ZFS on Linux. My initial decision to use Linux 2 years ago as the main driver OS and Ubuntu as the distribution was based upon the exepectation to not have this as my hobby in the next years. And that expectation was fulfilled by Ubuntu 16.04 LTS.

japanese festival calendar

Posted on January 19, 2019January 20, 2019 by Daniel Kirstenpfad

Last year I had started to create a calendar that would hold all the events and festivals (まつり / matsuri) in Japan – especially Tokyo – I can get ahold of.

Since it has become a custom in my family to spend several weeks several times a year in the Tokyo area this calendar is used and updated frequently.

Of course it is a calendar you can export, import and subscribe to with any iCal / ICS capable device at your disposal. And probably that means any device that has a calendar app or a browser.

You can click this link and subscribe through google calendar: japanese matsuri calendar