BFree Brings Intermittent Computing To Python

Generally speaking, we like our computing devices to remain on and active the whole time we’re using them. But there are situations, such as off-grid devices that run on small solar cells, where constant power is by no means a guarantee. That’s where the concept of intermittent computing comes into play, and now thanks to the BFree project, you can develop Python software that persists even when the hardware goes black.

Implemented as a shield that attaches to a Adafruit Metro M0 Express running a modified CircuitPython interpreter, BFree automatically makes “checkpoints” as the user’s code is running so that if the power is unexpectedly cut, it can return the environment to a known-good state instantaneously. The snapshot of the system, including everything from the variables stored in memory to the state of each individual peripheral, is stored on the non-volatile FRAM of the MSP430 microcontroller on the BFree board; meaning even if the power doesn’t come back on for weeks or months, the software will be ready to leap back into action.

In addition to the storage for system checkpoints, the BFree board also includes energy harvesting circuity and connections for a solar panel and large capacitor. Notably, the system has no provision for a traditional battery. You can keep the Metro M0 Express plugged in while developing your code, but once you’re ready to test in the field, the shield is in charge of powering up the system whenever it’s built up enough of a charge.

The product of a collaboration between teams at Northwestern University and Delft University of Technology, BFree is actually an evolution of the battery-free handheld game they developed around this time last year. While that project was used to raise awareness of how intermittent computing works, BFree is clearly a more flexible platform, and is better suited for wider experimentation.

We’ve seen a fair number of devices that store up small amounts of energy over the long term for quick bouts of activity, so we’re very interested to see what the community can come up with when that sort of hardware is combined with software that can be paused until its needed.

IRC Over LoRa, For When Things Really Go South

As a society, we’ve become accustomed to always-on high-speed data connections, whether we’re at home on the computer or out and about with a mobile device. But what happens if a natural disaster knocks out the local infrastructure? Sure some people will be able to fire up their radio if they need to reach out and touch someone, but even among hackers, hams are a minority. What we really need is a backup Internet.

The team behind the CellSol project hopes to show that building a volunteer-operated distributed communications network is not only within the capabilities of the hacker community but probably much easier and cheaper to do than you might think. Each node in the network, known as a Pylon in CellSol parlance, can shuttle data between the LoRa backbone and WiFi-enabled devices like smartphones and computers. Once the network is up and running, users don’t need any special hardware or software to use it.

Now to be clear, nobody is talking about surfing the web here. When a user connects to one of the ESP32 Pylons, they’ll be able to access a simplistic chat system through their browser. If the Pylon has an active Internet connection the chat can be bridged to an IRC channel. Without Internet connectivity, the pylon will simply give users on the CellSol network a means to communicate among each other. To keep things simple there’s no user names, private messages, or encryption. This is bare-bones, end-of-the-world style communication.

Want to join the CellSol revolution? All you really need is an ESP32, a LoRa radio, and the open-source firmware. If you get something like the Heltec LoRa 32 development board, you don’t even need to solder anything together. Just flash the board and go. Once you have a few Pylons going, you can also put together a cheap repeater node using a LoRa equipped Arduino. Both devices are small and energy efficient enough that they could easily be battery or solar powered. As you can see in the video after the break, the team even envisions a future where they could be dropped off in public areas via drone.

This isn’t the first time we’ve seen the ESP32 used to establish an off-grid LoRa communications network, and like those previous attempts, it’s usefulness will largely depend on how many people you can convince to set up their own nodes and repeaters. But if you’ve got some open minded friends who live relatively close by, this could be a great way to have a little chat.

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Four Years Later, Off-Grid Office Shed Still Rocks

About four years ago, [Russell Graves] created what was, to him, the ultimate work-from-home environment: an off-grid office shed. The shed might look a bit small, but it’s a considerably larger workspace than most people in an office are granted. Four years later, in the middle of a global pandemic, working from home has become much more common and [Russel] shares some thoughts on working from home and specifically reflects on how his off-grid, solar powered shed office (or “shoffice” as he likes to call it) has worked out. In short, after four years, it rocks hard and is everything he wanted and more.

Its well-insulated plywood walls let him mount monitor arms and just about anything else anywhere he wants, and the solar power system allows him to work all day (and into the night if he wants, which he doesn’t) except for a few spells in the winter where sunlight is just too scarce and a generator picks up the slack. Most importantly, it provides a solid work-life separation — something [Russell] is convinced is critical to basic wellness as a human being.

That’s not to say an off-grid solar shed is the perfect solution for everyone. Not everyone can work from home, but for those who can and who identify with at least some of the motivations [Russell] expressed when we covered how he originally created his office shed, he encourages giving it some serious thought.

The only thing he doesn’t categorically recommend is the off-grid, solar powered part. To be clear, [Russell] is perfectly happy with his setup and even delights in being off-grid, but admits that unless one has a particular interest in solar power, it makes more sense to simply plug a shed office into the grid like any other structure. Solar power might seem like a magic bullet, but four years of experience has taught him that it really does require a lot of work and maintenance. Determined to go solar? Maybe give the solar intensity sensor a look, and find out just how well your location is suited to solar before taking the plunge.

Something’s Brewing Up In The Woods – And It Looks Stunning

Caffeine fuels the hacker, and there are plenty of options to get it into your system, from guzzling energy drinks to chewing instant coffee pellets. But let’s take a nice cup of coffee as input source, which itself can be prepared in many ways using all kinds of techniques. In its simplest form, you won’t need any fancy equipment or even electricity, just heat up some water over a fire and add your ground beans to it. This comes in handy if you’re camping out in the woods or find yourself in a post-apocalyptic world, and in case you still prefer a stylish coffee maker in such a situation — why let an apocalypse ruin having nice things? — you’re in luck, because [Andreas Herz] designed this nifty looking off-the-grid coffee maker.

The design somewhat resembles a certain high-end precision coffee maker that even fictional billionaires approve of, which [Andreas] created in Fusion 360 and is available online. The device base is made from brass, wood, and silicone he cast from a 3D printed mold, while the glass and ceramic parts — i.e. the water tank and coffee pot — are simply store bought. [Andreas] opted for fuel gel as heat source, which burns under a copper coil that acts as heat exchanger and starts the actual brewing process. It took him a few attempts to get it right, and in the end, a coat of black exhaust paint did the trick to get the temperatures high enough.

This may not be the fastest coffee maker, as you will see in the video after the break, but choosing a different fuel source might fix that — [Andreas] just went the safe(r) way by using fuel gel here. But hey, why rush things when you’re camping or having a cozy time in a cabin anyway. Now all you need is the right blend, maybe even your own, made with a camp stove coffee roaster. Of course, in case of an actual apocalypse, you may not have easy access to a CNC router or 3D printer, but then there’s always the option to build an espresso machine from salvaged motorcycle parts.

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Datacenter UPS Heads Home For Off-Grid Power Solution

The news sites seem never to be without stories of Elon Musk and his latest ventures, be they rapid transit tube tubes in partial vacuum, space flight, or even personal not-a-flamethrowers. Famous for electric vehicles, Musks’s Tesla also has a line of solar products and offers the Powerwall home battery power system. These are tantalizing to anyone with solar panels, but the price tag for one isn’t exactly a dream.

[Nathann]’s budget couldn’t stretch to a Powerwall, but he did have access to a hefty ex-datacentre uninterruptible power supply (UPS) and a large quantity of lead-acid cells. From this he built his own off-the-grid power in the cellar of the home. It’s not as elegant as a Powerwall, but it can power the house on moderate usage, so he claims, for up to ten days.

On one level the installation is more of a wiring job than one of high technology, but the logistics of dealing with nearly 100 lead-acid cells are quite taxing. The UPS takes four battery packs, each clocking in at 288 V. The cells are joined with copper straps, and the voltage and current involved is not for the faint-hearted. An accidental short vaporized a screw and a battery terminal; if this were our house we’d put fuses in the middle of the battery packs.

The batteries are stored on wooden pallets atop brick pillars in case the cellar floods. The basement installation now is ready for the addition of solar and wind-based off-grid sources. Maybe your battery power solution will be less hair-raising, but it’s unlikely to be cheaper. Meanwhile this isn’t the first such project we’ve seen, though others usually go for 18650 Li-Ion cells, the use of lead acid remains a viable and economical solution.

A Mobile Terminal For The End Of The World

If civilization goes sideways and you need to survive, what are the bare essentials that should go in your bunker? Food and fresh water, sure. Maybe something to barter with in case things go full on The Postman. That’s all sensible enough, but how’s that stuff going to help you get a LAN party going? If you’re anything like [Jay Doscher], you’ll make sure there’s a ruggedized Raspberry Pi system with a self-contained network with you when the bombs drop.

Or at least, it certainly looks the part. He’s managed to design the entire project so it doesn’t require drilling holes through the Pelican case that serves as the enclosure, meaning it’s about as well sealed up as a piece of electronics can possibly be. The whole system could be fully submerged in water and come out bone dry on the inside, and with no internal moving parts, it should be largely immune to drops and shocks.

But we imagine [Jay] won’t actually need to wait for nuclear winter before he gets some use out of this gorgeous mobile setup. With the Pi’s GPIO broken out to dual military-style panel mount connectors on the front, a real mechanical keyboard, and an integrated five port Ethernet switch, you won’t have any trouble getting legitimate work done with this machine; even if the closest you ever get to a post-apocalyptic hellscape is the garage with the heat off. We especially like the 3D printed front panel with integrated labels, which is a great tip that frankly we don’t see nearly enough of.

This is actually an evolved version of the Raspberry Pi Field Unit (RPFU) that [Jay] built back in 2015. He tells us that he wanted to update the design to demonstrate his personal growth as a hacker and maker over the last few years, and judging by the final product, we think it’s safe to say he’s on the right path.

Power Generation Modules Mix And Match Wind, Water, And Hand Cranks

What’s great about the Power Generation Modules project headed by [Cole B] is the focus on usability and modularity. The project is a system for powering and charging small devices using any number and combination of generator modules: wind turbine, hand-crank, and water turbine so far. Power management and storage is handled by a separate unit that acts as a battery bank to store the output from up to six generators at once. There’s also a separate LED lamp module, designed to be capable of being powered directly from any of the generator modules if needed.

Testing the water turbine module

The hand crank is straightforward in concept, but key to usability was selecting a DC gearmotor with a gear ratio that made cranking by hand both comfortable and sustainable; too weak of a crank and it’s awkward, too hard and it’s tiring. The wind turbine has three compact vanes that turn a central shaft, but testing showed the brushless motor it uses as a generator isn’t a good match for the design; the wind turbine won’t turn well in regular wind conditions. The water turbine prototype showed great success; it consists of an epoxy-glazed, 5 inch diameter 3D printed propeller housed in a section of PVC pipe. The propeller drives a brushless motor which [Cole B] says easily outputs between eight to ten volts when testing in a small stream.

The team has plans for other generators such as solar, but this is a great start to an array of modules that can be used to power and charge small devices while off the grid. We’re happy to see them as a finalist for The Hackaday Prize; they were selected as one of the twenty projects to receive $1000 cash each in the Power Harvesting Challenge. The Human-Computer Interface Challenge is currently underway which seeks innovative ideas about how humans and computers can interface with one another, and twenty of those finalists will also receive $1000 each and be in the running for the Grand Prize of $50,000.