Martijn's musings

Electrical cabinet

A quick tour inside

Posted on July 13, 2021 | 8 minutes | 1541 words | Martijn Hemeryck

In earlier posts, I did provide an overview of the architecture of my custom-made home automation system. I also did describe some specificities related to a wired home automation setup. For my system, I decide on wiring everything in a star-configuration, meaning all wiring around the house for lights, push buttons, … all converges in a centralized electrical cabinet. The focus of this post is to show you some details of what this cabinet looks like and some pointers for practical issues I had run into. [Read More]

Schematics

One-wire diagram and floor plan

Posted on July 6, 2021 | 5 minutes | 869 words | Martijn Hemeryck

In previous posts, I did discuss the importance of planning and design as well as details on the physical wires to be used. Here, I’d like to focus on two types of schematics which are not only very useful, but also mandatory for doing the electrical wiring for a Belgian house: the one-wire diagram and the floor plan. This post is a part of a larger series of posts on my home automation setup. [Read More]

home automation schematics tech

Wiring

Groundwork for a wired home automation setup

Posted on June 29, 2021 | 7 minutes | 1450 words | Martijn Hemeryck

In this post, I will take a deeper dive into the bottom layer, the wiring. Different kinds of inputs and outputs can be discussed, but for the sake of simplicity, I will focus on a push button operating a lamp. These components will also come back later on in the series. This post is a part of a larger series of posts on my home automation setup. See the home automation overview post, to learn about the rationale and a description of the other posts! [Read More]

home automation wiring tech

Architecture

My home automation layout

Posted on June 22, 2021 | 8 minutes | 1558 words | Martijn Hemeryck

Prior to actually building anything, it is important to think on a higher level what the various components are and how they will interact with each other, i.e. the architecture. Over the process of doing my own setup, I came across a large number of different possible configurations, each with their own benefits and downsides. For the first part of this post, I will focus on the final layout. While discussing the architecture, it is important to realize there are a number of different layers of abstraction to reason about these. [Read More]

home automation mqtt tech

Why

My vision for a modern home automation system

Posted on June 15, 2021 | 4 minutes | 804 words | Martijn Hemeryck

This post shall be the first in a series of blog posts where I intend to outline my home automation setup. For this first post, I want to start by first explaining why I worked on this. Secondly, I want to give some more attention to the vision and guiding principles I will use further on. At the end, there is an overview of all the future posts that I have currently planned for this series. [Read More]

homeautomation tech

Bootstrapping a pi4

bootstrapping a raspberry pi4 with arch for ARM

Posted on February 21, 2021 | 4 minutes | 676 words | Martijn Hemeryck

I’ve recently bought myself a raspberry pi 400, a small form factor keyboard with a raspberry pi 4 4GB RAM built into it. In hindsight, there are probably very few scenarios in which such a computer makes actually makes sense to me, but it still looks quite nice. I first took it for a spin using the raspberry pi OS that was on the SD card that came along with the set, but while I can acknowledge that it works quite OK out of the box, it just looks so ugly. [Read More]

tech raspberry pi 4 note-to-self

Updating GPG subkeys

My yearly yubikey GPG subkey rotation process

Posted on July 9, 2019 | 3 minutes | 523 words | Martijn Hemeryck

This is just a list of things to consider when updating my GPG subkeys (encryption, signing, authentication) for the particular setup I use on a daily basis: one master key without any expiry date to generate and revoke subkeys I use pass as my password manager. the basic idea is that it’s a command-line password manager that uses gpg under the hood for encrypting / decrypting the passwords. the passwords are encrypted with an encryption subkey pass allows managing its history with git, linking the storage on a remote gitlab / github server. [Read More]

gpg yubikey note-to-self

MQTT over TLS

Posted on November 12, 2018 | 3 minutes | 472 words | Martijn Hemeryck

MQTT is a popular lightweight protocol for use in home automation. If features a central broker where each of the clients can communicate with in a pub / sub fashion. Since I’ve been toying around with some home automation setups, I was curious how to secure it with TLS. Mosquitto The most commonly used broker implementation I have come across is mosquitto and is quite straightforward to setup on most *nix flavors. [Read More]

mqtt note-to-self