Playin' around with Electronics and Computers
From simple, standard electric cable I built a capacitive sensor to assess the water level in my water container. While the circuit was replicated from this blog (thanks for sharing!), I’d like to share how I built the actual capacitor.
Continue reading “Simple Capacitive Water Sensor for a Water Container”
Using ultrasonic distance sensors I monitor water levels for my garden irrigation system. I have an underground rainwater cistern and a wooden barrel as an interim water storage in the sun to have the water warmed up before use. I started off with the classic HC-SR04 ultrasonic distance sensor, but it turned out to be a bad idea for the warm water barrel: Moisture and temperatures up to 40°C in the summer sun made the sensor rot within half a year down to complete failure. I switched to AJ-SR04M watertight sensor (which seems to be very similar to JSN-SR04T which is often also mentioned on the internet). This has a higher minimum distance (~20 cm vs. ~2 cm), and a much larger opening angle (45° to 75° vs. 15°) as compared to the HC-SR04, and in this post I describe how I dealt with that.
Continue reading “Lessons Learned: Measure Water Levels in a Barrel with SR04-Type Sensors”
This is just a quick note that I updated my Tardis housing for my media center to now hold a Raspberry Pi 4. The new version features:
Continue reading “Quick Thing: TARDIS Housing for Raspberry Pi modded for Raspberry Pi 4”
The Diamex/Tremex All-AVR programmer for ATmel microcontrollers comes as “naked” populated PCB, no case, no protection against shorts or other damage. I created a case for it, with the following design criteria:
Continue reading “Quick Thing: Case for Diamex All-AVR Programmer”
I replaced the stock hotend of the Fabtotum Personal Fabricator Hybrid Head v1 by an E3D Lite6 hotend (The full metal V6 should work the same way). In this post I describe the steps to remove the old hotend, get in the new hotend and the simple modifications to the firmware that were required.
Continue reading “Replacing Fabtotum Hybrid Head v1 Hotend with E3D Lite6”
It always bothered me that I could not modify the text (“Save my name, email, and website in this browser for the next time I comment.”) of the cookie consent checkbox in the WordPress comments section to explicitly mention that it uses cookies. Continue reading “Quick Note: Modify the WordPress Comments Cookie Consent in an Update-stable Way”
I wanted to have a floating table of contents for my posts, but could not find any free plugin that allowed me to do so. Using a combination of plugins, I created a floating TOC myself, which is not perfect, but good enough.
For a relative that’s paraplegic, I modified the housing of the remote control for the electric wheelchair wheels Alber e-motion M25 to make the usage easier. Mainly, the small housing was made thicker and larger for better handling. Also, one knob was moved to a different position.
The project is not very sophisticated, but I publish it anyhow – perhaps some other handicapped person can benefit from it.
Continue reading “Modified Housing for Alber e-motion M25 Remote Control”
In order to prevent my venetian window blinds to go down on timer in front of my open window-style terrace door, potentially locking me out, I needed to know if the door handle was in the “open” position. However, I did not want to use a battery powered radio sensor, but the existing door open/close magnetic sensor in the door frame. Here’s my solution.
Continue reading “Convert Window/Door Sensor to Handle Sensor”
The approach for creating feature-rich hiking maps described in my earlier post was limited in area, since it uses the Overpass API to download OSM data. The Overpass API has a restriction with regard to the amount of data downloadable in one go. In this post I describe a way to download a much larger area if needed, using the PBF files available from Geofrabrik and processing them with Osmosis.