Thomas shares makes

A few years ago, I designed and built my own rainwater tank level sensor for fun. Unfortunately the unthinkable happened: the grommet sealing the cable inlet leaked and its insides got wet... I had to fix it or get an other one.

My brother had installed a submersible Pressure Transducer in his rainwater tank, and rather than improving my old project I chose to use his aproach and get an off the shelve sensor to measure the tank level and use the saved time for other fun projects.

My openHASP control panels have been an eye catchers on my desk for years now. I've been using the WT32-SC01 Plus one for over a year to keep an eye on the electric power use in our house.

I designed a fancy power dial with extra arc indicators on the outside and a dynamic list of the biggest power consumers in the middle..

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.

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 want to keep counters for how much solar panel energy and grid energy my car uses. I have power meters for the Solar, Grid and the car. The power the rest of the house uses is however unknown, and measured by the grid meter. Determining the car's part of grid and solar power requires some calculations.

I created home assistant template sensors to come up with these power numbers, and added integrators to obtain energy meters. The energy flow plus card can show these in real time on the Home assistant dashboard.

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.

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.

This project combines electronics, water and creating something from scratch. I couldn't resist designing my own reed switch array water level sensor.

This kind of sensor has a floating part with a magnet moving up and down a sensor tube.

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.

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 was able to cook up a fun audio setup controlled and automated with Home Assistant! It features

• Multiple room synchronised audio speakers (fixed/analog, portable Bluetooth devices and via app on phone or tablet)
• Playback of internet radio, Spotify streaming and local audio files.
• Sound notifications for Doorbell, garden gate and other sensors and home alarm events.

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.

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 read on Facebook someone bought low-cost filament from http://www.owl-filament.de/. I'm always interested in alternative sources of filament to use with my 3D printer, so I took a look.

I already had a limited set of PETG spools in nice colors and was interested in some cheaper spools for prototyping purposes. The price was 'cheap' indeed, read along to see how this manufacturer's quality turned out to be...

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.