If It Ain’t Broke… Add Something To It

Given that we live in the proverbial glass house, we can’t throw stones at [ellis.codes] for modifying a perfectly fine Vornado fan. He’d picked that fan in the first place because, unlike most fans, it had a DC motor. Of course, DC motors are easier to control with a microcontroller, and next thing you know, it was sporting an ESP32 and a WiFi interface.

The original fan was surprisingly sparse inside. A power supply, of course, and just a tiny PCB for a speed control. Oddly, it looks like the speed control was just a potentiometer and a 24 V supply. It wasn’t clear if the “motor” had some circuitry in it to do PWM control or not. That seems likely, though.

Regardless, the project opted for a digital pot IC to maintain compatibility. One nice thing about the modification is that it replaces the existing board with the same connectors. So if you wanted to revert the fan to normal, you simply have to swap the boards back.

Now the fan talks to home automation software. Luckily, there’s still nothing wrong with it. We love seeing bespoke ESPHome projects. Even if your fan has WiFi, you might not like it communicating with Big Brother.

If IRobot Falls, Hackers Are Ready To Wrangle Roombas

Things are not looking good for iRobot. Although their robotic Roomba vacuums are basically a household name, the company has been faltering financially for some time now. In 2024 there was hope of a buyout by Amazon, who were presumably keen to pull the bots into their Alexa ecosystem, but that has since fallen through. Now, by the company’s own estimates, bankruptcy is a very real possibility by the end of the year.

Hackaday isn’t a financial blog, so we won’t get into how and why iRobot has ended up here,  although we can guess that intense competition in the market probably had something to do with it. We’re far more interested in what happens when those millions of domesticated robots start getting an error message when they try to call home to the mothership.

We’ve seen this scenario play out many times before — a startup goes belly up, and all the sudden you can’t upload new songs to some weirdo kid’s media player, or the gadget in your fridge stops telling you how old your eggs are. (No, seriously.) But the scale here is unprecedented. If iRobot collapses, we may be looking at one of the largest and most impactful smart-gadget screw overs of all time.

Luckily, we aren’t quite there yet. There’s still time to weigh options, and critically, perform the kind of research and reverse engineering necessary to make sure the community can keep the world’s Roombas chugging along even if the worst happens.

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Nest Thermostat: Now 100% Less Evil

If you have a Nest thermostat of the first or second generation, you probably noticed it recently became dumber. Google decided to pull the plug on the servers that operate these devices, turning them into — well — ordinary thermostats. Lucky for us [codykociemba] has been keeping up with various exploits for hacking the thermostat, and he started the NoLongerEvil-Thermostat project.

If you want to smarten up your thermostat again, you’ll need a Linux computer or, with some extra work, a Mac. The thermostat has a DFU-enabled OMAP loader. To access it, you have to plug it into USB and then reboot it. There is a narrow window for the loader to grab it, so you have to be running the software before you reboot or you’ll miss it.

You can control your thermostat again!

After that, the flash is relatively fast, but the Nest will look dead for a brief time. Then the No Longer Evil logo will show, and you are in business. We wish the hack simply replaced the Google software with a local website, but it doesn’t. It redirects all the network traffic to a custom URL. Then you can control your thermostat from the nolongerevil.com website. So we don’t know what will happen if they decide to stop hosting the remote server that powers this. You can also run the code locally if you’ve got a server up.

If you get another year out of your trusty thermostat, that’s a year you wouldn’t have had otherwise. We do worry a bit about putting an odd device on your network. In theory, the project is open source, but all the important bits are in a binary U-Boot image file, so it would take some work to validate it. To get you started, the command to dump the content is probably: dumpimage -T kernel -p 0 -o kernel uImage. Or, you could watch it with Wireshark for a bit.

We were happy to get some more use out of our Nest.

Dark lab setup with scientific looking drink dispenser

Scared For A Drink?

Halloween is about tricks and treats, but who wouldn’t fancy a bit to drink with that? [John Sutley] decided to complete his Halloween party with a drink dispenser looking as though it was dumped by a backstreet laboratory. It’s not only an impressive looking separating funnel, it even runs on an Arduino. The setup combines lab glassware, servo motors, and an industrial control panel straight from a process plant.

The power management appeared the most challenging part. The three servos drew more current than one Arduino could handle. [John] overcame voltage sag, brownouts, and ghostly resets. A healthy 1000 µF capacitor across the 5-volt rail fixed it. With a bit of PWM control and some C++, [John] managed to finish up his interactive bar system where guests could seal their own doom by pressing simple buttons.

This combines the thrill of Halloween with ‘the ghost in the machine’. Going past the question whether you should ever drink from a test tube – what color would you pick? Lingonberry juice or aqua regia, who could tell? From this video, we wouldn’t trust the bartender on it – but build it yourself and see what it brings you!

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Testing Cheap DC Breakers And How To Not Start Fires

One characteristic of adding PV solar to homes is a massive increase in high-voltage and high-current DC installations. With this comes a need for suitable breakers, but without the requisite knowledge it can be easy to set up a fire hazard. There is also the issue of online shopping platforms making it easy to get fuses and breakers that may not be quite as capable as they claim, never mind being rated for DC use.

Recently [Will Prowse] had a poke at a range of common purportedly DC-rated breakers from everyone’s favorite US-based seller of tat, to see whether they should be bought or avoided at all cost. Perhaps unsurprisingly the cheap breakers are about as dodgy as you’d imagine. With a hundred plus amps flowing through them they get surprisingly crispy, even if they generally did their job. Minus the few that arrived in a broken condition, of course.

Ultimately [Will] found that the molded case circuit break (MCCB) by one ‘DIHOOL’ performed the best. Compared to the competition, it is much larger and has sizeable terminals that avoid the quaint heat-soaking issues seen with the cheap-and-cheerful rest. At a mere $34 for the 125A-rated version, it’s still a fraction of the cost of a comparable Eaton MCCB, but should upset your insurance company significantly less than the alternatives.

Don’t forget to add in fuses, with [Will] testing a range of cheapo 12V DC fuses, to see which one will prevent fires, and which one cause them. Unsurprisingly, some of them like the Bojack-branded ones ran very hot, making them more of a liability than an asset.

As for what makes DC breakers so different from AC one is that the extinguishing point of a DC arc is much steeper, which means that an AC breaker is likely to fail to extinguish the arc when used for DC applications. This is why a properly rated and ideally certified breaker is essential, and also not really the point where you want to start saving money.

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HRV Gets Home Automation Upgrades

In our modern semi-dystopia, it seems like most companies add automation features to their products to lock them down and get consumers to buy even more proprietary, locked-down components. The few things that are still user-upgradable are getting fewer and farther between, but there are still a few things that can be modified and improved to our own liking like this control panel for a heat recovery ventilator (HRV).

HRVs are systems that exchange fresh, outside air with stale, inside air while passing them both through a heat exchanger to keep from wasting energy. Many systems run continuously but they aren’t always needed, so some automation is beneficial. This upgrade from [vincentmakes] improves the default display for a Zehnder Comfoair Q350 HRV with a color display as well as adding it in to a home automation system, letting a user control fan speeds remotely as well as alerting the user when it’s time for filter replacements and providing up-to-date information from all the sensors in the HRV.

The project builds on a previous project which adapted an ESP32 to interact with the CAN bus used on these devices. With these upgrades the user can forgo the $300 proprietary upgrade that would be needed to get the same functionality otherwise. It’s also fully open-source so all that’s needed is to flash the firmware, replace the display, and enjoy the fresh air. There’s other modern HVAC equipment that can benefit from new controllers and a bit of automation as well.

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Kitchen Bench Splash Guard Powered By Arduino

If you’re blessed with high water pressure at home, you probably love how it helps blast grime from your dishes and provides a pleasant washing experience. However, it can also cause a wonderful mess when that water splashes all over your countertops. [vgmllr] has whipped up a simple solution to this problem by installing an automatic splash guard.

So tidy!

The concept is simple enough—install a pair of flat guards that raise up when the sink is running, in order to stop water getting everywhere. To achieve this, [vgmllr] grabbed an Arduino, and hooked it up to a piezo element, which acts as a water sensor.

The piezo is attached to the bottom of the sink, and effectively acts as a microphone, hooked up to one of the Arduino’s analog-to-digital pins. When water flow is detected, the Arduino commands two servos to raise a pair of 3D printed arms that run up and down the outside of the sink. Each arm is fitted with magnets, which mate with another pair of magnets on the splash shields inside the sink. When the arms go up, the splash shields go up, and when the arms go down, the splash shields go down.

It’s an ingenious design, mostly because the installation is so clean and seamless. By using magnets to move the splash shields, [vgmllr] eliminated any need to drill through the sink, or deal with any pesky seals or potential water leaks. Plus, if the splash shields are getting in the way of something, they can easily be popped off without having to disassemble the entire mechanism.

It’s a tidy little build, both practical and well-engineered. It’s not as advanced as other kitchen automations we’ve seen before, but it’s elegant in its simple utility.