willem.com blog

Collecting health data with Biostrap

Wearing a clinical-grade photoplethysmography (PPG) sensor for a month

Nov. 15, 2017
Wearing a clinical-grade PPG sensor for a month to collect advanced biometrics from my wrist.

Most wearables (smartwatches, fitness trackers, etc.) use very basic sensors to capture heart rate. Their signal is binary: just counting beats. Biostrap is different, instead of just checking pulses, it captures a high-fidelity PPG waveform. These waveforms are the same kind that doctors use, making me wonder what I could learn from them!

From tree to table

Designing and creating a night stand

Oct. 23, 2017
Creating a night stand from a raw slab of chestnut wood.

Right next to the house were I was born there was this chestnut tree, sadly it died one and a half year ago. When it was taken down, my brother saved me a slab of wood. I intended to create something from it, a nice "do it yourself" adventure, worthy of a blog post!

Saving a MacBook Air with exploded battery

Don’t try this at home - but I did

Sep. 14, 2017
Saving a MacBook Air with a swollen battery pack.

Last night I had a nasty surprise: my original MacBook Air was swollen due to an exploded battery. I immediately had to take action, for reasons of safety and to preserve this piece of modern computer history. Don’t try this at home, but if you do... read along for some practical tips.

Climbing Mount Etna

Visiting an active volcano on Sicily, Italy

Sep. 2, 2017
Climbing Mount Etna, an active volcano on Sicily Italy.

Last week me and my wife went to Sicily for a little summer holiday. It is the largest island in the Mediterranean Sea. It is an autonomous region of Italy, along with surrounding minor islands. It's home to Europe's largest active volcano: Mount Etna. We had a chance to visit this lava spurring monstrosity and it was quite the experience.

Clouds below my floor

Building a little datacenter in my basement

Aug. 31, 2017
Building a little datacenter in my basement utilising a very fast internet connection.

At my home I have this crazy fast optical internet connection. It is a 600MB up and down fibre connection which directly arrives in my home (no copper cables involved). It's like a private internet highway. Reason enough to find out if I could do something to make better use of all this speedy fiber galore...

The day I killed my LAN

Turned off my local network and went 4G only

July 31, 2017
I killed my office LAN and went 4G only. Saves a lot of clutter, energy and money.

Today I called my provider to quit my office's ADSL internet subscription, I don't need it anymore. I have turned off my local area network and switched my workflow onto mobile internet only. The simplicity and savings actually surprised me so much, that I made blog post for it.

Fietselfstedentocht 2017

Cycling the 235KM bicycle tour through Friesland

June 30, 2017
Cycling the 235KM long Fietselfstedentocht through Friesland

This month I cycled the Fietselfstedentocht, a 235KM tour through Friesland. This tour brings you through various Frisian cities throughout one of the most Northern provinces of the Netherlands. The tour was first organised in 1912 and has grown to become legendary due to its history, challenge and popularity; well worthy of a blog post!

Beast of the Green Hell

Driving the Mercedes-AMG GT R

May 31, 2017
Blog post about an amazing AMG Circuit day at the race track of Zolder, Belgium.

This month I received an invitation to join Mercedes at the Zolder circuit in Belgium to drive in "the beast". The Mercedes-AMG GT R, a furious green coloured performance car that gets its nickname from the Nürburgring where it was developed. It was an incredible experience, well worth a blog post!

Smartwatches vs Mechanical watches

Why I still wear mechanical and why smartwatches have potential

Apr. 30, 2017
Why I still wear a mechanical watch and why smartwatches have potential.

Technology has come a long way since the first computer. Smartwatches today are very much an achievement of miniaturisation of technology. I recently used an Apple Watch Series 2 to find out if technology has come far enough to replace my mechanical watch, today I share you my findings.

Repairing a Nintendo Gameboy Advance SP

Chip surgery to play classic Zelda

Mar. 26, 2017
Reparing an old Nintendo Gameboy Advance to play classic Zelda again.

This month Nintendo released the Switch with Zelda "Breath of the Wild". The new console received positive reviews. The new Zelda game is amazing and can be played on-the-go, thanks to the portability of the Nintendo Switch. But it its hardly the first Nintendo device that features the mythical kingdom of Hyrule with Link and princess Zelda. I found an old Gameboy Advance, perfect for playing classic Zelda games... but it was in need for repair!

Programming on Apple Watch

Serious about crazy experiments

Feb. 16, 2017
Programming with VIM over SSH on Apple Watch using a bluetooth keyboard

Over the past years I have been no stranger to crazy experiments, but this time I really wanted to push it into the extreme: programming on an Apple Watch. Would it be possible to actually write code on such a tiny device? Why even bother? This post is about the case for crazy experiments, and why you should try too!

iPad Pro next to my primary machine

Using it with Apple Pencil as a creative powerhouse

Jan. 30, 2017
Using iPad Pro with Apple Pencil next to my computer to form a create powerhouse

I wanted see if I can find something better than my old fashioned pencil and paper that I use for designing software as professional developer. I knew iPad Pro from my test last summer, figuring out if it could replace my primary development machine. While it may not be able to completely replace my thrustworthy ThinkPad, it turned out to be a totally different story when it comes to paper.

One year of cycling

GPS recording an entire year of bike rides using Garmin and Strava

Dec. 31, 2016
GPS recording an entire year of bike rides using Garmin and Strava.

One year ago I started recording all my bike rides, including commutes, short grocery trips and long Gran Fondos. I equipped my bicycles with Garmin Edge computers that recorded location (GPS), speed, cadence and my heart rate. I covered more than 7683 kilometers during 320 hours of riding. It's time to review all the data and share some photos I took along the ride!

Being a volunteer in Amsterdam-Zuidoost

Computer support in the local community center

Nov. 21, 2016
About my work as volunteer in the local community center in Amsterdam Zuidoost

After realising how lucky I am as an healthy, well educated, young man with a solid income, I wanted to do something for other people as volunteer. It just so happens to be that two years ago I received a flyer in my mailbox from the local community center: they were looking for someone with some knowledge of computers. A very interesting journey was about to begin!

Harvesting boredom to let creativity flourish

using the Punkt MP01 dumb phone

Oct. 1, 2016
What does it mean for my state of mind and creativity if I am no longer be constantly connected to the Internet using a smartphone.

Smartphones are everywhere in the modern society we live in today. Through our 4G and WiFi connections the internet is just one tap away. In fact, it is so close that it feels like a natural extension. But is this wealth of information all good or does it have a downside too? It seems like an interesting experiment to go app-less for a while and solely use a dumb phone.

Batavus Champion bike from 1978

restoring retro glory with some help from the Internet

Sep. 3, 2016
Restore the retro glory of an old bike from the 70s using the internet.

Almost a year ago I bought an old steel racing bike from 1978. I wanted to figure out if using a bike to commute worked for me. It did! I used it to ride more than 1000KM before I decided to get a modern road bike. Now, almost a year later, I decided to put the powers of the internet into good use: to bring the bike back to its retro glory!

iPad Pro as primary computer

testing iOS as primairy development platform

Aug. 15, 2016
Is the time right to use an iPad as primary development platform to get some real work done?

The lack of physical clutter, distracting branding, or blinking LED's makes the iPad Pro a textbook example of minimal design. My despiction of distraction explains my interest in using the iPad Pro as only computer to test if it is up to the task. Is Apple's latest effort on iOS enough to enable it to do serious development work?

Cash is king, or is it?

The wallet- and cash-less experiment

July 15, 2016
Is the time right to ditch the wallet?

Very often I see men carry a wallet filled with plastic: multiple debit and credit cards plus a bunch of loyalty programs and membership cards. Then, some even top it off with stinky paper money and sticky metal coins! It made me wonder if I can free up one pocket by ditching the wallet?

Building the blog... in style!

Developing on a 20-year old computer with 16MB RAM and Windows 98

June 23, 2016
Find out if it is possible to turn a computer from the 90s into a modern development machine.

One must be a bit crazy to come up with the idea to build a blog (as in: actual programming) on an old 486 laptop with just 16MB RAM. I happen to be that crazy: I took my very first laptop from the 90s and decided to find out if it was possible to turn it into a development machine.