It Works on My Machine™

Sometimes you get nipped in the butt by a small, usually insignificant detail that just happens to be significant in your specific situation. Today I ran into such a "gotcha", and it reminded me of a story that fits nicely.

Update VMWare ESXi SSL certificate

Another post in the category: I keep reinventing the wheel (or: I keep forgetting how I did stuff in the past). Here's how to renew your ESXi SSL certificate.

Another "How to boot your Raspberry Pi from SSD"

This is another short one in the category: "I keep forgetting, so let's document it". This post contains the steps to make your Raspberry Pi boot from an external device like an SSD or HDD. It works on Raspbian (Debian) 12 (Bookworm). I haven't tested this on any other versions.

Wemos D1 Mini won't write?

Ok, this is a short one. On a few occasions when I'm trying to write a Wemos D1 Mini, no matter what I try, it won't write. Since I've "fixed" this on many occasion but I keep forgetting how I'm actually writing it down now so next time I won't have to scratch my head for so long. It's simple...

Andonstar AD208 battery compartment fix

For a long time I wondered why my Andonstar AD208 wouldn't keep time, even though I placed an 18650 battery in the battery compartment. If it couldn't do that, then what was even the use of the battery that could clearly be placed in the microscope?

Shelly: The device is already owned by another user/account

This post has two parts. The first part is most likely what you're here for: Getting rid of this stupid error. It turns out that is quite easy and I will explain in a second. The second part, however, is how this (apparently) happens, how Shelly deals with this issue and how Shelly exposed another customer's details to me.

Hack your Segway E110S / E110SE / E125S

We used to rent scooters from time to time because myself, the misses and the kids like to go for rides on sunny days. It didn't take long before we decided that keep renting scooters wasn't a viable option and that we should treat ourselves to our very own scooters. After doing some research, nerd as I am, we ended up buying two Segway E110SE's.

The DIYMore 18650 Battery Shield V3 su... isn't very good.

Earlier this week I was working on a project where I wanted to power some electronics with an 18650 cell. Because I needed 5V and 3.3V and an 18650 doesn't provide either I dove into my grab stock and came out with one of the "DIYMORE" battery shields I had in stock, ordered on the cheap from AliExpress when I stumbled upon them one day. So I put an 18650 in, soldered the electronics to the 3.3V and 5V rails, checked if everything worked and went on my merry way.

Using Data Protection in Entity Framework Core with Value Converters (v1.1)

This post is intended as an addendum on Mgr. Jiří Činčura's excellent post Using Data Protection in Entity Framework Core with Value Converters (archive 1, archive 2). In it, he explains how you can use an Entity Framework Core ValueConverter to encrypt data before it being stored in the database and decrypt it when reading from the database.

Install Microsoft SQL Server on Debian

Short howto on how to best install MSSQL on Debian (bullseye). Based on Microsoft's documentation for Ubuntu.

Toshiba Airconditioner WiFi troubles

This week I had three airconditioners installed - 2 Toshiba Kazumi's (RAS-B07J2KVSG (archived)) with optional WiFi module (archived) and a Haori (RAS-N4KVRG-E (archived)) which has the WiFi module built-in. Unfortunately I was on vacation during installation so the installers couldn't setup the AC's with my WiFi. Being reasonably capable of figuring this out myself I told them not to bother and I'd do it myself. I was aware of the (only) requirement of the WiFi modules for the AC's: they require a 2.4Ghz WiFi connection.

Storing IP's and networks in SQL Server efficiently

When you Google on how to store IP addresses efficiently in SQL server few approaches keep coming up. Most of these approaches most notably tend to 'forget' about IPv6 and work exclusively for IPv4 IP addresses. Other approaches use a (var)char to store IP addresses and this works fine, as long as your (var)char allows up to 39 characters if you want to be able to handle IPv6 IP addresses. It'll also work fine whenever all you need to do is store an IP address or maybe even search for a specific IP address, such as in logging scenarios, where you can write SELECT * FROM MYTABLE WHERE [ip] = '192.168.0.1'. However, when storing networks (such as 192.168.0.0/24 in CIDR notation) things get a bit harder. If you want to find all networks that 'contain' a given network you're in for some trouble. Another solution is to store IP's as (var)binary. Again, most solutions I found only worked with IPv4 but it's perfectly possible to store both IPv4 and IPv6 IP's in a single (var)binary field.

Udemy family sharing

Udemy is having one of their sales and a lot of the courses seemed interesting for my kids, my wife or myself. We always use our separate accounts and keep them to ourselves. For everything. However, since I couldn't find any information on family-sharing (as you can with, say, Steam for example) I purchased some courses on my account and decided to share my account with my family (thanks LastPass for making that easy!).

Loud Mean Well LRS-350-24 fan

Recently I bought a Mean Well LRS-350-24 AC/DC power supply to drive a decent length of LED strips. It turns out the fan in this power supply is kind of loud - it has only kicked in twice but both occasions I was astonished about the loudness of the fan. A quick Google showed that I'm not alone in this.

How to erase your SSD / HDD using hdparm

I recently had to ship some (used) drives back to the manufacturer. And even though I'm pretty sure the drives will be erased first thing and even though the drives were used in a RAID (actually SHR2) set with an encrypted volume and it would be hard, if not impossible, to recover anything from them without my help I'm still never too keen to keep my bits and bytes on drives that are out of my hands. Selling my laptop? Erase drive. Recycling an old workstation? Erase drive. Then use a hammer to whack a screwdriver through the drive or "drop" (rather: throw) the drive on the ground a few times. You never know where a drive ends up and in who's hands.

WD Red NAS drives use SMR and I'm not happy about it - understatement of the year

If you're into NAS drives then you may have heard that recently word got around that Western Digital's NAS drives, the WD Reds specifically, apparently use SMR - Shingled Magnetic Recording. There's been a lot of fuss about it and I'm not about to repeat it all so that's why I'll provide some links to other sources I came across myself. What this blogpost is about, though, is me documenting what happened after I contacted WD from a customer perspective. Your experience may vary, but what you're about to read is mine.

Handling multiple implementations of an interface with Dependency Injection in .Net Core

When you have an interface with multiple implementations and you don't want to use a 3rd party DI framework, you'll need to work around some limitations of the 'native' DI implementation in .Net Core.

Swashbuckle custom ordering of controllers

By default, Swagger (or rather: Swashbuckle) orders the documentation of controllers by controllername. So if you have a FooController, BarController and BazController they will be ordered as Bar, Baz, Foo in the swagger UI. Let's change that.

Configure your Windows Remote Desktop (RDP) to use TLS with a StartSSL certificate

I wanted to use TLS with non-self-signed certificates for RDP connections to my workstation at home and so I set out to make it happen. Since I don't have a domain with Active Directory (anymore...) the 'usual' methods found on the web don't quite apply. Here's a simple, step-by-step, guide on how to use StartSSL certificates to secure your RDP connection. This should also work fine with certificates from other CA's; step 2 and 3 (obtaining the .crt file)  can/will be different but other than that you should be fine.

Do you really want "bank grade" security in your SSL? Dutch edition

Inspired by Do you really want "bank grade" security in your SSL? Here’s how Aussie banks fare found on /r/programming I present to you the "Dutch edition". The author used Qualys SSL Labs' SSL test to determine how good banks' SSL implementations really are.