Close-up of the mod installed into the HDMI switch, tapping the IR receiver

Interfacing A Cheap HDMI Switch With Home Assistant

You know the feeling of having just created a perfect setup for your hacker lab? Sometimes, there’s just this missing piece in the puzzle that requires you to do a small hack, and those are the most tempting. [maxime borges] has such a perfect setup that involves a HDMI 4:2 switch, and he brings us a write-up on integrating that HDMI switch into Home Assistant through emulating an infrared receiver’s signals.

overview picture of the HDMI switch, with the mod installed

The HDMI switch is equipped with an infrared sensor as the only means of controlling it, so naturally, that was the path chosen for interfacing the ESP32 put inside the switch. Fortunately, Home Assistant provides the means to both receive and output IR signals, so after capturing all the codes produced by the IR remote, parsing their meaning, then turning them into a Home Assistant configuration, [maxime] got HDMI input switching to happen from the comfort of his phone.

We get the Home Assistant config snippets right there in the blog post — if you’ve been looking for a HDMI switch for your hacker lair, now you have one model to look out for in particular. Of course, you could roll your own HDMI switch, and if you’re looking for references, we’ve covered a good few hacks doing that as part of building a KVM.

All the components of the Piggymeter interface laid out on a silicon mat

Simple Optical Meter Sets New Standards For Documentation

PiggyMeter is a wonderful example of a device that you never knew you needed – simple, elegant, easy to build, and accompanied by amazing documentation. It’s a snap-on interface for electric meters, dubbed so because its 3D printable shell looks like a pig nose, and it works with IEC62056-21 compliant meters. If you want to learn about your home’s power consumption in real time and your meter happens to fit the bill, look into building a PiggyMeter, it’s the kind of DIY project that a hacker was destined to design at some point.

All you need is a printed shell, a Wemos-compatible development board with an ESP32 MCU, an optical interface board, and a few small parts like a ring magnet. The optical interface board is not open source, but there’s drawings available, and the design is pretty simple, so it should be trivial to recreate. Plus, it’s also reasonably inexpensive if you don’t want to build your own board. Got parts? Simply put them all together, flash the firmware, and you have a meter adapter added to your smart home device family.

This device works with HomeAssistant, and it’s incredibly easy to set up, in part because of just how clearly everything is outlined in the blog post. Seriously, the documentation is written with love, and it shows. If you’re looking to learn how to document a device in a helpful way, take notes from the PiggyMeter. And, if you’d like to learn more about optically coupled power meter interfaces, here’s a different open source project we’ve covered before!

Bringing The Voice Assistant Home

For many, the voice assistants are helpful listeners. Just shout to the void, and a timer will be set, or Led Zepplin will start playing. For some, the lack of flexibility and reliance on cloud services is a severe drawback. [John Karabudak] is one of those people, and he runs his own voice assistant with an LLM (large language model) brain.

In the mid-2010’s, it seemed like voice assistants would take over the world, and all interfaces were going to NLP (natural language processing). Cracks started to show as these assistants ran into the limits of what NLP could reasonably handle. However, LLMs have breathed some new life into the idea as they can easily handle much more complex ideas and commands. However, running one locally is easier said than done.

A firewall with some muscle (Protectli Vault VP2420) runs a VLAN and NIPS to expose the service to the wider internet. For actually running the LLM, two RTX 4060 Ti cards provide the large VRAM needed to load a decent-sized model at a cheap price point. The AI engine (vLLM) supports dozens of models, but [John] chose a quantized version of Mixtral to fit in the 32GB of VRAM he had available.

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Image of the presenter on the podium, in front of the projector screen with graphs shown on it

Supercon 2022: [Alex Whittemore] On Treating Your Sensor Data Well

If you build your own devices or hack on devices that someone else has built, you know the feeling of opening a serial terminal and seeing a stream of sensor data coming from your device. However, looking at scrolling numbers gets old fast, and you will soon want to visualize them and store them – which is why experienced makers tend to have a few graph-drawing and data-collecting tools handy, ready to be plugged in and launched at a moment’s notice. Well, if you don’t yet have such a tool in your arsenal, listen to this 16-minute talk by [Alex Whittemore] to learn about a whole bunch of options you might not even know you had!

For a start, there’s the Arduino Serial Plotter that you get for free with your Arduino IDE install, but [Alex] also reminds us of the Mu editor’s serial plotter – about the same in terms of features, but indisputably an upgrade in terms of UX. It’s not the only plotter in town, either – Better Serial Plotter is a wonderful standalone option, with a few features that supercharge it, as [Alex] demonstrates! You don’t have to stop here, however – we can’t always be tethered to our devices’ debugging ports, after all. Continue reading “Supercon 2022: [Alex Whittemore] On Treating Your Sensor Data Well”

the PCB without the case on, showing the screen, battery, and removable sensor

2023 Hackaday Prize: A Reusable Plant Monitor

[Ovidiu] cares for their house plants, trying to dial in the perfect soil humidity and light levels. However, many cheap monitors tend to rust after a few weeks of sitting in a damp, slightly acidic environment. By creating a custom plant monitor with a removable probe, not only can [Ovidiu] integrate better with their Home Assistant setup, but it will also be less wasteful.

The build starts with an ESP32-S3, a TP4056 charging circuit, a small e-ink display, and an AHT20 IC for air humidity and temperature. The ESP32 reads the probe using the capacitance measuring devices for touchpads built into the chip. Or course, a 450mAh battery provides a battery life of about 11 days. The probe is just a bare PCB with a connector at the top, making them cheap and easy to swap. They included pads on the probe for a thermistor for reading soil temperature, but this is optional. A handsome 3D-printed case wraps it all up nicely.

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DIY 3D Printed Rain Gauge Connects To Home Assistant

Measuring local rainfall has real practical uses, especially in agriculture, but most of us will have to admit that it’s at least partly about drawing cool graphs on a screen. Whatever your motivation, you can build this open source electronic rain gauge designed by [Sebastian] of Smart Solutions for Home, and integrate it with Home Assistant.

This 3D printed rain gauge is of the ubiquitous tipping bucket type and uses a magnet and hall effect sensor to detect every time the bucket tips out. The sensor is soldered to a custom PCB with ESP32 configured using ESP Home. By keeping it in deep sleep most of the time and only waking up when the tip of the bucket, [Sebastian] estimates it can run about a year on four AA batteries, depending on rainfall. The hinge mechanism is adjustable to ensure that both buckets will tip with the same volume of water.

FDM 3D printed enclosures are not known for being waterproof, so [Sebastian] coated the PCB with varnish to protect it from moisture. This worked well enough that he could leave it running in a bowl of water for a few hours without any ill effects. The end result looks good and should be able to handle the outdoors for a long time.

Building a weather station is a popular DIY project. Some of the interesting varieties we’ve seen are powered by supercapacitors, show readings on antique analog dials and convert parking distance sensor kit into a wind gauge.

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An Elegant Solution For Smart Home Device Integration

Integrating non-smart devices into your home automation system can be a cumbersome process, involving the wiring of multiple modules. However, [Pricelesstoolkit] has created the ESPClicker — a compact, ESP8266-based module that can remotely “press buttons” and simplify this process.

The ESPClicker’s core feature is its three relays that can be soldered to the button terminals of any existing “dumb” device, as [Pricelesstoolkit] demonstrated with his coffee machine in the video after the break. One of the relays can also be configured in the normally closed configuration. A compact twelve pin connector provides a removable wiring interface for the buttons, additional relays, power and even a contactless power detector that can be wrapped around an AC wire.

[PricelessToolkit] has done several Home Assistant related projects, and we recently featured his little Home Assistant controlled guardian bot. We’ve also seen other project that make use of ESPHome, like a iPod style scroll wheel and a LEGO train set.

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