IMadeAThing on karl

Monitoring HVAC system with ESPHome

Sat, 02 Nov 2024 00:00:00 +0000

Using ESPHome to Monitor HVAC System

Here’s a quick “show-and-tell” about a recent project I completed.

The concept

I’m not sure how I first came across the idea of measuring air pressure drop across a filter to gauge its remaining life, but I remember thinking it was a great idea.

Conceptual diagram for the project.

The idea has been lurking in the back of my mind for a while, but I never got around to implementing it… until now.

Watch Band RFID fob

Sat, 14 Sep 2024 00:00:00 +0000

Watch Band RFID fob

This is a quick project to create a wearable RFID fob that can be easily attached to a watch band. The idea is to have a small RFID tag that can be used for various purposes, such as access control or identification that is - more or less - as convenient as a surgically implanted tag, but without the need for embedding anything in your body.

Integrating ESPHome with a cheap Geiger Counter

Wed, 09 Nov 2022 00:00:00 +0000

Yes, there have been loads of people doing similar things! ESPHome already has a tutorial covering exactly this!

I’m writing this up because the approach that I ended up taking was not the intended/planned approach.

The Geiger Counter

I originally pulled the trigger on this particular version because it had a built in screen attached to a micro controller.

I naïvely thought that I’d be able to get a simple UART from the 4 pins next to the microcontroller or maybe even get data directly off of the micro USB port.

ESPHome for Sinilink PC remotes

Sat, 22 Oct 2022 00:00:00 +0000

PC (power) remote control

While doing research for a potential project, I stumbled onto a device that fit’s so squarely into that “it’s so simple and obvious, why didn’t I think tof that?!” category that I immediately placed an order for a few.

That device?

A simple WiFi equipped micro controller that gets wired between the power button on a PC and the motherboard. This makes it possible to remotely control and monitor the power state of any PC!

I made a thing: GPS/PPS clock source for ntpd

Sat, 15 Oct 2022 00:00:00 +0000

Tip

This is just a ‘pointer’ post.

All the details are in the kquinsland/yet-another-gps-pps-opnsense repo on github.

For the longest time, I had a dedicated raspberry pi with a GPS module acting as the ntp server for my home network. I chose to use a dedicated host for this because my router - at the time - did not have a serial port that I could leverage.

I made a thing: Yet another 3d printed speaker

Wed, 31 Aug 2022 00:00:00 +0000

Background

Long story made very short: the amplifier inside my ancient 2.1 desktop speakers died and I couldn’t find anything “off the shelf” that would serve as a suitable replacement and integrate well with Home Assistant.

So if you can’t buy it, you have to build it! And as it turns out, there’s a whole community of audiophiles that have published designs on all the usual places you’d find free designs for makers. Similarly, there’s a few companies that seems to specialize in audio electronics aimed specifically at people that are building their own speaker systems and just want someone else to handle the electronics and software.