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Amsterdam on Willem's Blog

Designing and implementing a (micro) payment system

Monetising my blog with coffee, Apple Pay and Mollie

Mar. 25, 2020
Designing and implementing a micro payment system with an emphasis on simplicity. Read about how I did it in this post.

Online payments are now more important than ever as businesses are disrupted by the COVID-19 virus. It drives my customers to seek new ways to make money online. I designed and implemented a (micro)payment system. This post is about achieving simplicity by solving complex challenges.

The day I sold my car

Looking back at my years with Smart Roadster

Feb. 13, 2020
This week I sold my car, I now no longer own one. I look back at my years of owning a sports car, if you're looking for a reason to buy one you should check this out.

This week I sold my car, I now no longer own one. For me, this is something of a change as over the years I owned various sports cars that were like a hobby to me. My discovery of cycling and the birth of my son changed this. But if you're looking for a reason to buy a sports car, read along!

Building a professional 72TB NAS

Configuration and installation of an HPE ProLiant DL380 server

Nov. 22, 2019
This month I installed a professional HPE ProLiant DL380p server in a datacenter in Amsterdam, read this post to see how this was done!

Over the past few years I have been moving my data and work from local computers (mostly laptops) into the cloud. Cloud computing is done by servers in a datacenter, powerful computers that do the hard work. As my company grew, I needed more capacity. It was time to add some power to my cloud!

Visiting an international hackers conference

OWASP Global AppSec Amsterdam

Sep. 27, 2019
This month I attended Global AppSec Amsterdam, an international conference for hackers and security specialists. Read along for some of the highlights.

This month I was lucky enough to attend Global AppSec Amsterdam, an international conference for hackers and security specialists. There were presentations from former intelligence agents, bounty hunters, academics and software vendors. I learned about some of the newest hacking techniques, met with interesting people and played some cool retro games. Read along for more.

Riding with a power meter on your bike

Installing and using the 4iiii Precision Powermeter

Aug. 28, 2019
In this post I describe my experience with installing the 4iiii Precision Powermeter on my road bike.

After I created a minimal road bike, I decided to install a power meter to find out what's it like to measure the power output of my legs. What can you learn from a power meter? Is it difficult to install? Is it worth it? Read along to find out.

Assembling a cargo bike

Setting up the Babboe Big cargo bike

June 25, 2019
How hard can it be to assemble a cargo bike? This posts shares my experience with assembling the Babboe Big cargo bike.

This month our Babboe Big cargo bike arrived, in boxes. The engineer in me thought it was a good idea to assemble the bike by hand. This way I would know exactly about all its parts and fittings, handy knowledge for maintenance. Read along for my experience and some practical tips.

Solo around the Markermeer (211KM)

Tips to prepare, to endure and to enjoy long distance cycling

May 29, 2019
This week I took my bike for a long distance (211)KM ride around the Dutch Markermeer, solo! Read along for practical tips for long distance cycling.

This week I took my bike for a long distance (211KM) ride around the Dutch Markermeer, solo! Unlike participating in an organised event with service, support and company along the way, going solo requires a different preparation, mindset and planning. Read along for some practical tips for long distance cycling.

The best bike computer app: Cyclemeter

Get advanced ride data with a flexible setup

Apr. 30, 2019
Collect advanced bike ride data using your smartphone connected to external Bluetooth sensors and a steer mounted display.

This month I have intensified my training to become fit for this year's Fietselfstedentocht, a 235KM bicycle ride through Friesland. Over the years I have tested different kinds of bike computer setups: from dedicated (and expensive) Garmin Edge bike computers to no data at all. Eventually I came up with a flexible setup to gather advanced ride data using my smartphone, let me explain how this works.

Servicing a robot vacuum cleaner

My iRobot Roomba is now running for 8 years and counting!

Mar. 20, 2019
This week it was time for some maintenance on my iRobot Roomba robot vacuum cleaner. Read along to learn how I did it.

Back in 2011 I got myself an iRobot Roomba 555 robot vacuum cleaner to automatically clean my apartment. It's a little circle shaped robot that drives around sucking up dust bunnies. Over the years it has bravely fought the dangers of my apartment... shoes, cables, carpet and belts. It survived and it is still working perfectly! This week it was time for some maintenance.

One year on the ultimate commuter bike

6000KM in 12 months with Gates CDN/CDX and Shimano Alfine

Feb. 27, 2019
Answering questions from one of the most popular posts of last year, I am reviewing my commuter bike after one year of extensive use through winter and summer.

A year ago I tried to create the ultimate commuter bike, a modified Sensa Cintura with the Gates CDN/CDX carbon belt drive. I received lots of messages from cyclists and commuters from all over the world. From the Swiss alps, France, Italy, Germany, United States and even "down under", Australia! You all wanted to know: how does the upgraded bike hold up?

Born with MCADD

Medium chain acyl-CoA dehydrogenase deficiency

Jan. 29, 2019
Our son was diagnosed with MCADD days after he was born. We experienced a metabolic crisis but were lucky to be just in time!

Just days after our son was born, we ran into trouble when our little man didn't want to eat anymore. Repeated attempts to feed him failed as he appeared to be too tired to drink from his mother. When we measured his body temperature we were shocked, only 33º Celsius! What followed was nothing less than an incredible emotional rollercoaster!

Do amazing things with a focused mind

Taking an ice bath and swimming in the Amstel river

Dec. 6, 2018
Read about my experience during the workshop I got as a birth day present involving the Wim Hof Method.

Just when the temperature was a low 2° Celsius, I jumped in the Amstel river! While it was nearly freezing outside I went for a swim, just moments after I've taken an ice bath! This post is about the incredible birthday present I got, a workshop involving the Wim Hof Method.

Around town in an electric car

Driving the Smart Electric Drive (EQ fortwo)

Nov. 16, 2018
For one week I drove the electric Smart EQ fortwo in and around town. I found out what it's like to drive electrically: fun!

Earlier this month I drove around town for a week in an electric vehicle, a brand new Smart Electric Drive (EQ fortwo). I used it to commute, for my daily groceries and to visit family, friends and customers. What's it like to drive a fully electric car on a daily basis?

Rescuing files from a broken harddisk

Make backups to be safe rather than sorry!

Oct. 16, 2018
Yesterday I helped a young woman with her broken computer containing precious photos, could I safe them?

Yesterday a young woman brought me her laptop, it didn't start anymore and it only showed an error message. It turned out to be a broken harddisk. It startled her when I told her that all data on the disk was lost. She told me it contained precious photos of her pregnancy and young child. What could I do?

Swimming and cycling with Apple Watch

Different activities in the workout app in watchOS

Sep. 27, 2018
This month I tested the newest watchOS while swimming and cycling.

This month Apple launched a new Apple Watch series and released an update to watchOS. The focus of the smartwatch is more and more gearing towards health and fitness. This made me curious, how well does Apple Watch work for different activities?

Helping people with free software

Installing Debian GNU/Linux on an old laptop

July 20, 2018
This week I helped a man with repairing and reinstalling his computer with Debian GNU/Linux.

This week a man brought his laptop to the community centre where I help people with computer problems as volunteer. The old laptop wouldn't start anymore and had to be reinstalled. Instead of Windows, I installed a free operating system. I think it is important to tell you how and why I did it.

Off the grid: Working on 100% renewable energy

Collecting, storing and using solar electricity to power my phone, computer and wearables

Apr. 30, 2018
Learning from powering my personal devices using nothing but self generated electricity using a solar panel and power banks.

For the past 10 days I have powered my personal electronic devices (phone, computer, wearables) using nothing but energy collected using a small solar panel. I disconnected all grid-connected chargers. I hoped that by going off the grid, even in such a small way, I would gain insights that enable me to save energy (and money).

Commuting by bike

One week (240KM) on the VanMoof Electrified S

Dec. 2, 2017
One week on the VanMoof Electrified S E-bike testing it for commuting and comparing it to a normal bike.

For a few years now, I commute to work using a bicycle. I have lost more than 15KG since I stopped using my scooter. This week I tested a VanMoof Electrified S, an electric bike with an industrial, minimal design. Is it any good? How does it compare to a normal bike? Will an electric bike make you lazy? Read along to find out!

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!

All blog posts
My 'bike area network': sensors (red) and displays (green) connected to the smartphone
My 'bike area network': sensors (red) and displays (green) connected to the smartphone
Wim Hof in ice blocks wearing sensors
Wim Hof in ice blocks wearing sensors
Normal (non-electrified) vs Electrified bike
Normal (non-electrified) vs Electrified bike
Schwalbe Marathon Plus Tour - designed to be unplattable (so far, its holding up!)
Schwalbe Marathon Plus Tour - designed to be unplattable (so far, its holding up!)
My bike in Winter
My bike in Winter
Not your typical hot tub... taking an ice bath!
Not your typical hot tub... taking an ice bath!
First gran fondo was cycling around the Dutch
First gran fondo was cycling around the Dutch "Markermeer", a 208.5KM ride.
That nail should not be there... puncture!
That nail should not be there... puncture!
What matters most is the ride itself, don't forget that!
What matters most is the ride itself, don't forget that!
The mechanical disc brakes have no trouble stopping you
The mechanical disc brakes have no trouble stopping you
Histogram of time and heart rate, showing how long (% of total time) a given heart rate was measured. (blue is electric, red is normal)
Histogram of time and heart rate, showing how long (% of total time) a given heart rate was measured. (blue is electric, red is normal)
iRobot XLife extended capacity battery
iRobot XLife extended capacity battery
Remove dust from the sensor underneath the wheel base
Remove dust from the sensor underneath the wheel base
Once the front of a server, now part of the solar panel mounting fixture
Once the front of a server, now part of the solar panel mounting fixture
Installing the disk in the laptop
Installing the disk in the laptop
Handling payment status updates
Handling payment status updates
The VanMoof app
The VanMoof app
Make sure to check the wheel bases for dust bunnies
Make sure to check the wheel bases for dust bunnies

More Amsterdam on Willem's Blog

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