Thomas shares makes

I integrated a 7€ YF-B7 water flow sensor into my home assistant setup using an off the shelve 35€ modbus based pulse counter.

A laser engraver can also make it easy to prepare bare circuit boards for etching at home though! I'll explain how I do this, and how it makes creating PCB's very easy if you have an etch tank in your lab.

The installer did not place a capture tray, but I want to avoid water dripping and pooling on the driveway during the heating season so we don't get a slippery ice spot or perhaps the continuous flow of water might even find its way into the brick wall.

Motion sensors; the simplest kind of automation, and the most useful. Especially during night, when you're finding your way to the smallest room in the house. I could not find a sensor I liked however, and also did not want to spend a lot of money on something ugly. So I designed and 3D printed my own.

When we renovated our living room, we upgraded the window roller shutters with electric motors. While we usually only open and close all of them together, we still want to be able to set them to individual positions. I decided to make a central control panel with 6 physical buttons and implement some logic in the Siemens Logo controller to control the motors.

I built a prototype test setup that makes sure every Watt produced by our solar panels is used by an electric heater. It uses an industrial power controller and some code to match the heater's power usage to whatever power is not used by the house.

This would make it possible to maximize our solar self consumption, which is required to get a decent return on your solar investment.

I chose to place our our rainwater tank's pump and filter in the garden shed slightly away from the main house. This allowed for a cheaper pump outside the tank and minimizes in-house technical equipment and noise.

Since the Rust programming language is all the rage, I started exploring this programming language during the summer. These are my notes on what I needed to do to set up a working development environment using the hardware I already had in my lab.

In November 2022 I saw a cool device at a Matter event. The device was presented as an unobtrusive way to interact with technology. Unlike usual touch screen devices, it looks like a wooden plank that is sensitive to touch and uses a LED pixel matrix behind the wood to visualize icons and text.

Since the device wasn't available for sale, I wondered how easy it would be to DIY a (much) simpler version that I could use for some of the same tasks.

I worked on this for a few hours each week, and by the end of December I had this simple proof of concept, making use of cheap parts and easy to assemble.

I call it the OpenPlank. Check it out...

After having the rainwater tank installed and connected to the roof, there was still quite some plumbing missing. The filter and calmed inlet add up to hundreds of euros. In my case the way the tubes were connected to the tank made off the shelve filters unusable, so I opted to DIY everything.

I configured GIT's difftool command to show the changed files as diff-split file tabs I can easily cycle through by pressing gt.

My favorite radio show airs on Sunday afternoon, and I often can't listen to it live. Fortunately the radio station offers a podcast feed so I can catch up and listen to old shows. I set up a systemd user timer (cronjob) on my Linux computer that runs getpodcast to download updates.

I printed this miniature cart/robot to show my son I can use my 3D printer and electronics hobby to build things he too can enjoy.

While I was minding my son at home while his kindergarten group was in quarantine, he asked me what a certain piece of electronics was for. He pointed to a reflection sensor that I was re-purposing for a project I was working on.

Living in a house with Aterno resistive electric heating, I wanted to get a feel of how our thermostat settings and outside temperature impacts our electricity bill.

I did not want to change the electric installation to add invasive interfacing like current sensing, and hacked a ZigBee door sensor to report on the heater's status LED.

I use a Raspberry Pi to drive two sets of speakers using Snapcast. To maximize the range of my Bluetooth speaker, I bought a Realtek RTL8761B-based USB Bluetooth dongle with a large antenna.

To get the Bluetooth dongle to work with the latest kernel drivers and bluez-alsa, I had to abandon Raspbian Linux and use the latest Debian Linux instead.

I discovered openHASP while I was searching for projects integrating touch interfaces with Home Assistant.

It's easy to wire up a cheap ESP microcontroller board and TFT display module, and by loading this opensource firmware you can turn it into a network connected touch control panel and control devices and display things.

When I bumped into a nice 2.8" TFT Desktop stand enclosure on thingiverse, I remembered I had an unused 2.8" ILI9341 display with resistive touch layer from a previous project.

Connecting the dots... I had all the necessary parts in my workshop, this would make a nice project to make over a weekend evening.

I discovered a lovely smart watch development platform; the Lilygo t-watch 2020. It's an ESP32 based hackable watch, with a small capacitive touch display.

I had already played with the idea of building a small home automation control and status display that fits into the existing switch cover plate, so clicked the order button and leveraged the open source watch firmware to quickly hack together a proof of concept.

While designing a screw-drive based RC tank (perhaps more on that later), I wanted to create a large easily customisable support structure out of a minimal amount of plastic. I started prototyping an interlocking structure in the shape of a octothorpe (#). This turned out to be a lot of ugly code, and so I got sucked into rabit hole of optimising my openscad model and found a cleaner solution.

At one point I wanted a basic home security system (burglar alarm) to offer me some peace of mind at night.

My Home Assistant instance has enough sensors to figure out what we are up to, so it was possible to create an alarm system that works autonomously. The system automatically arms and disarms while we sleep during the night and when we leave and return to the house during the day.

I have used an Ergotron standing desk for 5 years, then it broke, right out of warranty. Several years ago I started building a sensor device to track how much time I spend standing up versus sitting down in my chair. The hardware prototype finished, it got shelved since I found other fun things to do with my limited hobby-time.

Later I noticed that I was sitting down 99% of the time when working from home. To revive my healthy habit of working upright part of the time, I decided to pick up my parked project by re-printing the enclosure I made on my own printer and leveraging the power of esphome on and home assistant to finish the project after all.

I've been running network services on embedded arm platforms for for more than 8 years now, and when things go wrong, had to drag around HDMI monitors to hook up. For the last years I had a pi connected to the serial console to avoid that.

I have been mounting all my networking and smarthome devices on a DIN rail, and I had some small 2.2" TFT displays around for a different project.

I thought it would be nice to create a raspberry pi enclosure that included such a display so there's a real video console on the device that can also be used as status display.

I have a technical wall with several pieces of electronics mounted onto it. It started to look a bit disorganized, with all these things mounted at random places on the wooden board and cables running all over the place.

So I wanted to clean it up a bit... I stumbled upon a DIN-rail mount on Thingiverse, and remembered I had a piece of DIN rail in a box. Time to remix a bit and mount everything on DIN rail!

I have a USB connected flatbed scanner, a Canon CanoScan LiDE 110. I need to use it more frequently these days, and figured it would be handy if I connect it to my office-rpi and use it over the network.

At home and at work, I always tend to have around 5 small development boards on my desk. In a fixed setup with identical boards, metal or plastic standoffs can be a nice solution to build a stack that reduces the footprint on desk and avoid a spiderweb of cables.

In reality, the boards are of different sizes, and standoffs still cost a few euro's each. I knew I could do better, using a 3D printer and some parametric CAD modeling.

During COVID19 lockdown, the kids were running around the living room a lot more, and a lot more reckless. Our TV console is covered with glass plates. These have chamfered corners (45 degree cut off), but still it's a hard, glass corner, and I could imagine painful or catastrophic injuries and trips to the ER.

I decided to create a quick and dirty cover that, once installed, would provide safer plastic, rounded corners.