I built a smart heat recovery system!

Written by Ingmar Verheij on December 24th, 2017. Posted in Other

Begin 2015 I’ve started on my first IoT project; building a smart heat recovery system (or warmte terugwin unit – WTW). Back then I wrote an article (in Dutch, see here) explaining why I felt this was necessary and my initial approach. I never could have expected the journey I started, I had opened Pandora’s box.

I must admit it has been a fun ride with many ups and some downs (otherwise there would have been no ups)! I’ve learned so many things, ranging from hardware design, PCB’s, software coding and the IoT ecosystem in general. Mainly it’s been a journey refreshing my memory, some things I haven’t done since I was 17 and I was eager on learning it again.

In this article I want to share with you the result of *almost* 3 years of learning; my IoT project is finished

I don’t care-as-a-Service

Written by Ingmar Verheij on November 15th, 2015. Posted in Cloud, Geen categorie

I dont care as-a-serviceAfter many years of making fuzz about Cloud, it’s happening. Cloud is hotter than ever and companies are now seriously considering to change their strategy. Some choose a “Cloud where possible” strategy where others go for a “Cloud unless” approach.

So what is it that makes companies are so focussed on Cloud (after the industry hyped this for many years)? IMHO there’s a very simple reason: they don’t care about technology because they don’t want to care.

And you know what? It makes sense. Companies run a business, they provide services to their customers. They’re not an IT shop, they need IT to drive their business. This is a fundamental statement I’ve heard throughout my entire career told by every customer.

Companies don’t care how IT does it, it just needs to work. They need a service.

And there you go, there’s the one reason companies are moving to “Cloud”. Or better, they’re consuming services from other companies that specialised in that service. IT departments had their chance, for many years, to help businesses. They failed, miserably, over and over again.

Bediening WTW, altijd op de verkeerde plek?

Written by Ingmar Verheij on January 31st, 2015. Posted in Other

Brink 4 standenschakelaar

Sinds een jaar of twee woon ik een nieuwbouw woning waarin een WTW (warmeterugwinunit) zit om het huis van frisse lucht te voorzien en energie te besparen. Zo’n WTW installatie kan met behulp van een schakelaar in verschillende standen worden gezet. Sommige schakelaars zijn tevens voorzien van een indicatie-led voor het vervangen van de filters (dit is bij mij ook het geval).

Het idee van de standen is eenvoudig: 1 – ik ben op vakantie (laag) , 2 – ik ben thuis (normaal), 3 – ik kook / douche (hoog). Oftewel, als je gaat koken / douchen dan wordt er aangeraden om de schakelaar tijdelijk (30 min) in stand 3 te zetten. Nu vind ik koken discutabel wanneer je een afzuigkap hebt maar voor douchen valt iets te zeggen, het wordt immers best vochtig in een huis (waarin geen ventilatieroosters zitten).

Update 7-2-2015: Componenten besteld, eerste resultaten luchtvochtigheid en accu (zie onderaan).

Update 16-10-2017: PCB met componenten (rev 0.1) en interface gebouwd


Mijn dilemma

Ietwat onhandige locatie voor een schakelaar...Waarom zit deze schakelaar ALTIJD op de verkeerde plek? In de meeste huizen zit de knop OF in de keuken OF in de badkamer. In mijn geval is de locatie van de knop nog iets aparter, hij hangt naast de WTW-unit (op zolder, in een kast)… Daar ben ik overigens pas na 2 jaar achter gekomen (en dus ook dat er een indicatie-led is voor het vervangen het filter).

Zit de knop in de keuken dan moet je naar beneden als je gaat douchen en als de knop wel in de badkamer zit dan moet je eraan denken om de knop van 2 > 3 te zetten en na 30 min weer van 3 > 2. Dat laatste is probleem, maar als IT’er ben ik van nature lui aangelegd (“dat kan beter”).

Disable “Allow the computer to turn off the device to save power” for all WiFi adapters

Written by Ingmar Verheij on May 1st, 2014. Posted in Other

When a Windows computer enters sleep mode it ensures that WiFi adapters enters the device power state D3 (Sleep) and on resume ensure it puts it back to the device power state D0 (Full on).

Windows assumes that if a driver says it supports sleep states it handles this correctly, but this setting is known to cause some spontaneous disconnects with the access point (AP). Optionally Windows can be configured to place the WiFi adapters in device power state D4 (Off).

I wrote a PowerShell script that disables the “Allow the computer to turn off this device to save power” setting for all WiFi adapters.

Update 26/10/2017: Included an option to disable for all network adapters. 

Building a lab server

Written by Ingmar Verheij on April 29th, 2014. Posted in Other

Working in IT means you never stop learning, change is all around. To keep up with developments and to try out new ideas it’s essential to have a lab environment where I can play around with different technologies.

In the past I’d had a lab environment running in the cloud but I felt limited not having direct access to the hardware. While I have no intention to start experimenting with virtual GPU sharing yet, I might in the future. So I decided it was time to invest in a lab server to run at home. Since the server runs physically runs at home it needs to have fairly high wife acceptance factor (WAF). A stylish design, low power, low noise and fairly affordable server is desirable.