Fan With Automatic Door Is Perfect For Camper Vans

January 17, 2024 by Lewin Day 5 Comments

Ventilation fans are useful for clearing stuffy or stale air out of a space. However, they also tend to act as a gaping hole into said space. In the case of caravans and RVs, an open ventilation fan can be terrible for keeping the interior space warm, quiet, and free from dust. “Blast doors” or fan blocks are a common way to solve this problem. [Raphtronic] whipped up a duly-equipped ventilation fan to do just that.

The solution was to create a fan setup with a custom fan holder and a sliding door to block airflow when necessary. [Raphtronic] designed a fan frame for this purpose using parts 3D printed in ASA plastic. This material was chosen such that they could readily withstand the 50 C (120 F) temperatures typical in his Ford Transit camper during the summer. A simple 12 V ventilation fan was then fitted to the frame, along with a sliding door controlled by a 12 V linear actuator.

The mode of operation is simple. A DPDT switch controls the linear actuator. Flipped one way, the linear actuator is fed 12 V in such a polarity as to move it to open the fan door. In this mode, 12 volts is also supplied to the fan to start ventilation. When the switch is flipped the other way, the actuator moves to the closed position, and a diode in the circuit stops the fan spinning backwards. As a bonus, limit switches are built into the linear actuator, so there’s no need for any microcontrollers, “off” switch positions, or additional wiring.

It’s a tidy solution to the problem of ventilating a camper in a clean and effective manner. Files are on GitHub for those wishing to build their own. We’ve seen some great work in this area before, like this off-grid van project that made excellent use of 3D scanning during the build process. If you’ve designed and built your own nifty camping gear, don’t hesitate to drop us a line!

Feeding The Fire By Robot

January 15, 2024 by Bryan Cockfield 23 Comments

It might seem a little bit counterintuitive, but one of the more carbon-neutral ways of heating one’s home is by burning wood. Since the carbon for the trees came out of the air a geologically insignificant amount of time ago, it’s in effect solar energy with extra steps. And with modern stoves and well-seasoned wood, air pollution is minimized as well. The only downside is needing to feed the fire frequently, which [Anders] solved by building a robot.

[Anders]’ system is centered around a boiler, a system which typically sits in a utility area like a basement and directs its heat to the home via another system, usually hot water. An Arduino Mega controls the system of old boat winches and various motors, with a grabber arm mounted at the end. The arm pinches each log from end to end, allowing it to grab the uneven logs one at a time. The robot also opens the boiler door and closes it again when the log is added, and then the system waits for the correct set of temperature conditions before grabbing another log and adding it. And everything can be monitored remotely with the help of an ESP32.

The robot is reportedly low-maintenance as well, thanks to its low speed and relatively low need for precision. The low speed also makes it fairly safe to work around, which was an important consideration because wood still needs to be added to a series of channels every so often to feed the robot, but this is much less often than one would have to feed logs into a boiler if doing this chore manually. It also improves on other automated wood-burning systems like pellet stoves, since you can skip the pellet-producing middleman step. It also eliminates the need to heat your home by burning fossil fuels, much like this semi-automated wood stove.

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Bringing The Voice Assistant Home

January 14, 2024 by Matthew Carlson 22 Comments

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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A Dashboard Outside The Car

January 11, 2024 by Bryan Cockfield 11 Comments

One of the biggest upsides of open communications standards such as CAN or SPI is that a whole world of vehicle hacking becomes available, from simple projects like adding sensors or computers to a car or even building a complete engine control unit from the ground up. The reverse is true as well; sensors and gauges using one of these protocols can be removed from a car and put to work in other projects. That’s the idea that [John] had when he set about using a vehicle’s dashboard as a information cluster for his home.

The core of the build is an Astra GTE dashboard cluster, removed from its host vehicle, and wired to an Arduino-compatible board, in this case an ESP32. The code that [John] wrote bit-bangs an SPI bus and after some probing is able to address all of the instrument gauges on the dashboard. For his own use at home, he’s also configured it to work with Home Assistant, where each of the gauges is configured to represent something his home automation system is monitoring using a bit mask to send data to specific dials.

While this specific gauge cluster has a lot of vehicle-specific instrumentation and needs a legend or good memory to tie into a home automation system without any other modification, plenty of vehicle gauges are more intuitive and as long as they have SPI they’d be perfect targets for builds that use this underlying software. This project takes a similar tack and repurposes a few analog voltmeters for home automation, adding a paper background to the meters to make them easier to read.

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How To Build A Fully Offline Smart Home, Or Why You Should Not

January 9, 2024 by Maya Posch 88 Comments

So-called ‘smart home’ appliances and gadgets have become an ever-more present thing the past years, with nary a coffeemaker, AC unit or light bulb for sale today that doesn’t have an associated smartphone app, cloud service and/or subscription to enable you to control it from the beach during your vacation, or just set up automation routines to take tedium out of your busy schedule. Yet as much as [Calvin Wankhede] loves home automation, he’d very much like for it to not stop working the moment his internet connection goes down, or the company running the service goes bankrupt. This is where his journey to create an off-line alternative smart home based around Home Assistant and other (open) software began.

Although Home Assistant (HA) itself has become significantly easier to use, what becomes readily apparent from [Calvin]’s journey is that setting up and managing your own smart home infrastructure is a never-ending project. A project that involves finding compatible hardware that can tie into HA, whether or not without reflashing the firmware, resolving configuration issues and other assorted fun. If you are into this kind of thing, it is of course a blast, and it’s a good feeling when it finally all works.

Unfortunately, interoperability across smart home and similar IoT devices is still a far-off dream, even with the introduction of Thread and Matter (which incidentally are among the worst product names to search for, period), as Matter’s uptake is pretty abysmal. This thus leaves off-line smart homes mostly as the domain of the tech-inclined in search of a hobby.

Hidden Wall-Mount Table Looks Like Hanging Art

December 24, 2023 by Lewin Day 13 Comments

If you live in a compact space, sometimes you have to get creative with your furniture to make the most of it. This wall-hanging table design from [diyhuntress] is perfect for those situations where you need a table, but you don’t want it taking up the whole room when it’s not in use. Plus, it’s kinda stealthy, which makes it even more fun!

The table is a folding design, with a flat wooden top, and an equally-sized supporting leg that goes down to the ground. The other end of the table is supported by a frame on the wall, which also contains several shelves for small objects. The trick is that the table top and support are hinged together, so that they can fold up and sit in front of the shelves, essentially hanging the whole assembly from the wall. Even better, by painting a simple artwork on the support, the whole thing just looks like a decor piece with no clue as to its hidden functionality.

It’s a fun build, and one that you could easily knock out in a weekend with some basic woodworking skills. We’ve featured some other nifty shelf designs before, too. Just remember, too – a neat and tidy space is a boost to your hacker productivity, so don’t rule this out for your own use!

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Cat-o-Matic 3000 Serves Your Feline Masters

December 1, 2023 by Kristina Panos 8 Comments

When you have three cats and three humans, you have one problem: feeding them on a schedule without over or under feeding them. Even if there was only one human in the equation, the Cat-o-Matic 3000 would still be a useful tool.

Essentially, it’s a traffic light for cats — where green means you are go for feeding, and red means the cat was just fed. Yellow, of course, means the cat is either half-full or half-empty, depending on your outlook.

The brains of this operation is an ATmega88PA leftover from another project. There’s a no-name voltage regulator that steps up the two AA cells to 5 volts. Timing comes from a 32 kHz crystal that allows the microcontroller to stay in power-saving sleep mode for long periods of time.

Creator [0xCAFEAFFE] says the firmware was cobbled together from other projects. Essentially, it wakes up once per second to increment the uptime counter and then goes back to sleep. Short-pressing a button shows the feeding status, and long-pressing it will reset the timer.

Wanna make a cat status indicator without electronics? Give flexures a try.