Enjoy An Open-Source Espresso

March 24, 2023 by Bryan Cockfield 10 Comments

One of the core principles of the open-source movement is that anyone who wants to build on a piece of work, in whatever way they want, is easily able to. With source code freely available, the original project can be expanded upon, modified, updated, or simply looked at and used as inspiration. Usually we think about this in the realm of software freedom, but hardware is an important component as well. And not just electronics hardware, either. [Norm] demonstrates this espresso machine which was built on these open-source foundations.

The project takes some inspiration from the open-source Gaggiuino project, which was another build that modified an entry-level espresso maker with finer control over temperature and pressure. [Norm] was not willing to sacrifice his espresso machine for this cause, though, which is how this machine with its cobbled-together hardware came to be. An older machine with some worn parts was sacrificed to the coffee gods instead, making use of its pumps, boiler, and a few other bits of hardware especially from the hydraulics system. The software control is built around the Gaggiuino project, and includes a custom control board for user interface.

Right now the coffee maker does indeed work, but [Norm] hopes to make some improvements to the device including adding an enclosure of some sort, both to prevent accidental contact with the boiler and to give it a sleek, professional look. We kind of like it the way it is, while acknowledging that it isn’t quite ready for commercial production like this. It has a similar industrial feel as this espresso machine we featured a few years ago that is made out of old engine components.

Ondol: Korean Underfloor Heating

March 23, 2023 by Dave Rowntree 37 Comments

One of the many aspects of the modern world we often take for granted is the very technology that keeps our accommodation at a habitable temperature. Examples of this include centralized heating systems using hot-water circulation, or blown air ducted to multiple rooms from a central furnace. Certainly in Europe, once the Romans shipped out, and before the industrial revolution, we were pretty cold unless someone lit a fire in the room. Every room. But not in Korea. The Ondol heating principles have been used constantly from about 5000 BC to only a few decades ago, keeping your average Korean countryman nice and toasty.

Having said that, the sophistication has improved a bit. Initially, the idea was to simply heat up a bunch of rocks in the fire, and bring them indoors, but Ondol quickly became part of the building itself. As will be seen from the video embedded below, the house sits on top of an elaborate double stack of serpentine channels, that circulate the hot combustion products from the furnace as thoroughly as possible, slowing down the gases and allowing their heat to transfer into the structure of the floor, and then radiate into the space above. It does bear more than a passing resemblance to the Roman hypocaust system, ruined examples of which can be found all over the UK and Europe. The skill demonstrated in the video is considerable, but must surely be an expensive build reserved for the most culturally aware Koreans who wish to live in simpler (and less hectic) locations in their country.

Maybe for the vast majority of us, this kind of thing is not viable, and we’re more likely to benefit from a more centralized approach, perhaps using waste heat from data centers or geothermal activity. (See: Iceland)

Continue reading “Ondol: Korean Underfloor Heating” →

Smart Occupancy Sensor Knows All

March 23, 2023 by Bryan Cockfield 30 Comments

In the last few decades, building engineers and architects have made tremendous strides in improving the efficiency of various buildings and the devices that keep them safe and comfortable to live in. The addition of new technology like heat pumps is a major factor, as well as improvements on existing things like insulation methods and building materials. But after the low-hanging fruit is picked, technology like this smart occupancy sensor created by [Sina Moshksar] might be necessary to help drive further efficiency gains.

Known as RoomSense IQ, the small device mounts somewhere within a small room and uses a number of different technologies to keep track of the number of occupants in a room. The primary method is mmWave radar which can sense the presence of a person up to five meters away, but it also includes a PIR sensor to help prevent false positives and distinguish human activity from non-human activity. The device integrates with home automation systems to feed them occupancy data to use to further improve the performance of those types of systems. It’s also designed to be low-cost and easy to install, so it should be relatively straightforward to add a few to any existing system as well.

The project is also documented on this GitHub page, for anyone looking to build a little more data into their home automation system or even augment their home security systems. We imagine that devices like this could be used with great effect paired with a heating device like this, and we’ve also seen some other interesting methods of determining occupancy as well.

Continue reading “Smart Occupancy Sensor Knows All” →

Taking Apart IKEA’s Latest Air Quality Sensor

March 16, 2023 by Tom Nardi 27 Comments

Whether it’s because they’re concerned about worsening pollution or the now endemic variants of COVID-19, a whole lot of people have found themselves in the market for a home air quality monitor thee last couple of years. IKEA noted this trend awhile back, and released the VINDRIKTNING sensor to capitalize on the trend.

The device must have sold pretty well, because last month the Swedish flat-packer unveiled the considerably more capable (and more expensive) VINDSTYRKA. Now thanks to the efforts of [Oleksii Kutuzov] we’ve got a fantastic teardown of the new gadget, and some more information on the improvements IKEA made over its predecessor.

Certainly the most obvious upgrade is the addition of an LCD readout that displays temperature, humidity, and how many particulates the device detected in the air. There’s even a “traffic light” colored indicator to show at a glance how bad your air supply is. The other big change is the addition of wireless, though unlike the WiFi hacks we saw for the VINDRIKTNING, this built-in capability uses Zigbee and is designed to plug into IKEA’s own home automation ecosystem.

Speaking of those hacks, a GitHub user by the name of [MaartenL] chimes in to say they’ve managed to hook an ESP32 up to test pads on the VINDSTYRKA motherboard, allowing the parasitic microcontroller to read the device’s sensors and report their data on the network over a service like MQTT, without impacting the sensor’s normal operations. This is how the first hacks on the older VINDRIKTNING were pulled off, so sounds like a promising start.

But even if you aren’t looking to modify the device from its original configuration (how did you find this website?), it seems pretty clear the VINDSTYRKA is a well-built piece of kit that will serve you and your family well. Which is more than what could be said for some of the cheapo environmental sensors flooding the market.

Thanks to [killergeek] for the tip.

A Smart Home That CAN Do It All

March 15, 2023 by Matthew Carlson 39 Comments

In an ideal smart home, the explosion of cheap WiFi and Bluetooth chips has allowed hundreds of small wireless devices to control the switches, lights, and everything else required for a “smart home” at a relatively low price. But what if you don’t want hundreds of internet-connected devices in your home polluting the wireless spectrum and allowing potential security holes into your network? If you’re like [Lucas Teske], you might reach for something wired and use cheap and (currently) available Raspberry Pi Picos to create PicoHome.

The unique twist of PicoHome is that it uses a CAN bus for communication. One of [Lucas’] goals was to make the boards easily swappable when hardware failed. This meant board-to-board communication and protocols like I2C were susceptible to noise (every time a relay triggered, the bus would lock up briefly). The CAN bus is designed to work in an electrically noisy environment.

There are two parts to the system: pico-relay and pico-input. The first connects to a 16 relay board and can control 16 different 24v relays. The second has 16 optoisolators to read from 12v-24v switches and various buttons throughout the house. These can be placed in a giant metal box in a central wiring location and not worry about it.

The firmware and board files are all released under an Apache 2.0 license, but the CAN2040 library this project relies on is under GPL. We covered the CAN2040 library when it was first released, and it’s lovely to see it being used for something entirely unexpected.

Continue reading “A Smart Home That CAN Do It All” →

A Ground Source Heat Pump From An Air Conditioner

March 7, 2023 by Jenny List 35 Comments

When it comes to lower-energy home heating, it’s accurate in all senses to say that heat pumps are the new hotness. But unless you happen to work with them professionally, it’s fair to say their inner workings are beyond most of us. Help is at hand though courtesy of [petey53], who made his own ground source heat pump for his Toronto house using a pair of window-mounted air conditioning units.

Continue reading “A Ground Source Heat Pump From An Air Conditioner” →

Screenshot from the presentation, showing the datalogger product image next to the datalogger specs stated. The specs are suspiciously similar to those of a Raspberry Pi 3.

Reclaiming A Pi-Based Solar Datalogger

March 4, 2023 by Arya Voronova 7 Comments

There’s quite a few devices on the market that contain a Raspberry Pi as their core, and after becoming a proud owner of a solar roof, [Paolo Bonzini] has found himself with an Entrade ENR-DTLA04DN datalogger which – let’s just say, it had some of the signs, and at FOSDEM 2023, he told us all about it. Installed under the promise of local-only logging, the datalogger gave away its nature with a Raspberry Pi logo-emblazoned power brick, a spec sheet identical to that of a Pi 3, and a MAC address belonging to the Raspberry Pi Foundation. That spec sheet also mentioned a MicroSD card – which eventually died, prompting [Paolo] to take the cover off. He dumped the faulty SD card, then replaced it – and put his own SSH keys on the device while at it.

At this point, Entrade no longer offered devices with local logging, only the option of cloud logging – free, but only for five years, clearly not an option if you like your home cloud-free; the local logging was not flawless either, and thus, the device was worth exploring. A quick peek at the filesystem netted him two large statically-compiled binaries, and strace gave him a way to snoop on RS485 communications between the datalogger and the solar roof-paired inverter. Next, he dug into the binaries, collecting information on how this device did its work. Previously, he found that the device provided an undocumented API over HTTP while connected to his network, and comparing the API’s workings to the data inside the binary netted him some good results – but not enough.

The main binary was identified to be Go code, and [Paolo] shows us a walkthrough on how to reverse-engineer such binaries in radare2, with a small collection of tricks to boot – for instance, grepping the output of strings for GitHub URLs in order to find out the libraries being used. In the end, having reverse-engineered the protocol, he fully rewrote the software, without the annoying bugs of the previous one, and integrated it into his home MQTT network powered by HomeAssistant. As a bonus, he also shows us the datalogger’s main PCB, which turned out to be a peculiar creation – not to spoil the surprise!

We imagine this research isn’t just useful for when you face a similar datalogger’s death, but is also quite handy for those who find themselves at the mercy of the pseudo-free cloud logging plan and would like to opt out. Solar tech seems to be an area where Raspberry Pi boards and proprietary interfaces aren’t uncommon, which is why we see hackers reverse-engineer solar power-related devices – for instance, check out this exploration of a solar inverter’s proprietary protocol to get data out of it, or reverse-engineering an end-of-life decommissioned but perfectly healthy solar inverter’s software to get the service menu password.