Maker [Dala] showing powerwall statistics

From Vehicle-to-Grid To DIY Home Powerwalls

August 13, 2024 by 48 Comments

As battery-to-grid and vehicle-to-home technologies become increasingly mainstream, the potential for repurposing electric vehicle (EV) batteries has grown significantly. No longer just a niche pursuit, using retired EV batteries for home energy storage has become more accessible and appealing, especially as advancements in DIY solutions continue to emerge. Last year, this project by [Dala] showcased how to repurpose Nissan Leaf and Tesla Model 3 battery packs for home energy storage using a LilyGO ESP32, simplifying the process by eliminating the need for battery disassembly.

In the past few months, this project has seen remarkable progress. It now supports over 20 different solar inverter brands and more than 25 EV battery models. The most exciting development, however, is the newly developed method for chaining two EV packs together to create a single large super-battery. This breakthrough enables the combination of, for example, two 100kWh Tesla packs into a massive 200kWh storage system. This new capability offers an accessible and affordable way to build large-scale DIY home powerwalls, providing performance that rivals commercial systems at a fraction of the cost.

With these advancements, the possibilities for creating powerful, cost-effective energy storage solutions have expanded significantly. We do however stress to put safety first at all times.

Hungry for more home powerbanks? We’ve been there before.

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Cheap DIY Button Pad Uses Neat Punchcard Trick

August 13, 2024 by 16 Comments

A StreamDeck is effectively a really cool box full of colorful buttons that activate various things on your PC. They’re fun and cool but they’re also something you can build yourself if you’re so inclined. [Jason] did just that for his sim racing setup, and he included some nifty old-school tech as well.

An ESP32 is at the core of the build, listening to button presses and communicating with the PC. However, the build doesn’t actually use regular buttons. Instead, it uses infrared sensors wired up in a matrix. This was an intentional choice, because [Jason] wanted the device to be reconfigurable with different paper card overlays. There are ways to do this with regular buttons too, but it works particularly well with the infrared technique. Plus, each button also gets a Neopixel allowing its color to be changed to suit different button maps.

What’s really neat is that the button maps change instantly when a different overlay card is inserted. [Jason] achieved this with an extra row of infrared sensors to detect punched holes in the bottom of the overlay cards.

Once upon a time, even building your own keyboard was an uphill battle. Today, it’s easier than ever to whip up fun and unique interface devices that suit your own exact needs. That’s a good thing! Video after the break.

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Stemfie, The 3D-Printable Construction Set

August 13, 2024 by 3 Comments

Construction kit toys are cited by many adults as sparking great creativity and engineering talent in their youth. LEGO, Meccano, K’NEX, Lincoln Logs—these are all great commercial options. But what about printing your very own construction kit at home? Meet Stemfie.

Fundamentally, Stemfie isn’t that different from any other construction kit you might have seen before. It has various beams and flat plates that are full of holes so they can be assembled together in various ways. It also uses bolts, spacers, and small plastic nuts that can be tightened using a special hand tool. Think of a mixture between LEGO Technic and Meccano and that will get you in the ballpark. It includes neat motion components too, including gears, wheels, and even a large flat spring!

What can you build with it? Well, as every construction kit toy says, you’re only limited by your imagination! However, if your imagination is especially small, you can just use the Stemfie 3D YouTube channel for inspiration. It features everything from a ping pong ball catapult to a rubber-band driven car. Plus, since it’s all 3D printed, you can simply scale up the parts and build even bigger designs. Like a giant catapult that can hurl entire water jugs. Fun!

We’ve seen other projects in this vein before. One of our favorites is [Ivan Miranda]’s giant 3D printed assembly kit that he uses to build big monster toys.

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Portable Router Build: Picking Your CPU

August 13, 2024 by 23 Comments

I want to introduce you to a project of mine – a portable router build, and with its help, show you how you can build a purpose-built device. You might have seen portable routers for sale, but if you’ve been in the hacking spheres long enough, you might notice there are “coverage gaps”, so to speak. The Pi-hole project is a household staple that keeps being product-ized by shady Kickstarter campaigns, a “mobile hotspot” button is a staple in every self-respecting mobile and desktop OS, and “a reset device for the ISP router” is a whole genre of a hacker project. Sort the projects by “All Time” popularity on Hackaday.io, and near the very top, you will see an OpenVPN &Tor router project – it’s there for a reason, and it got into 2014 Hackaday Prize semifinals for a reason, too.

I own a bunch of devices benefitting from both an Internet connection and also point-to-point connections between them. My internet connection comes sometimes from an LTE uplink, sometimes from an Ethernet cable, and sometimes from an open WiFi network with a portal you need to click through before you can even ping anything. If I want to link my pocket devices into my home network for backups and home automation, I can put a VPN client on my laptop, but a VPN client on my phone kills its battery, and the reasonable way would be to VPN the Internet uplink – somehow, that is a feature I’m not supposed to have, and let’s not even talk about DNSSEC! Whenever I tried to use one of those portable LTE+WiFi[+Ethernet] routers and actively use it for a month or two, I’d encounter serious hardware or firmware bugs – which makes sense, they are a niche product that won’t get as much testing as phones.

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DIY Gaming Laptop Built Entirely With Desktop Parts

August 13, 2024 by 23 Comments

Gaming laptops often tend towards implementing more desktop-like hardware in the pursuit of pure grunt. But what if you were to simply buy desktop hardware yourself, and build your own gaming laptop? That would be very cool, as [Socket Science] demonstrates for us all.

The project began with lofty goals. The plan wasn’t to build something rough and vaguely laptop-like. [Socket Science] wanted to build something of genuine quality, that for all intents and purposes, looked and worked like a proper commercial-grade laptop. Getting to that point took a full 14 months, but the final results are impressive.

Under the hood lies an AMD Ryzen 5 5600X and a XFX Radeon RX6600, hooked into an ITX motherboard with some low-profile RAM sticks. Those components were paired with a thin keyboard, a touchpad, and a portable gaming monitor. Getting all that into a thin laptop case, even a custom one, was no mean feat. Ports had to be cut down to size, weird ribbon cables had to be employed, and heatsinks and coolers had to be rearranged. To say nothing of all the work to 3D print a case that was strong and actually worked!

The full journey is quite the ride. If you want to go right back to the start, you can find part one here.

We’ve seen some builds along these lines before, but seldom few that get anywhere near this level of fit and finish. Oftentimes, it’s that kind of physical polish that is most difficult to achieve. All we can say is “Bravo!” Oh, and… video after the break.

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The Long, Slow Demise Of DVD-RAM

August 13, 2024 by 35 Comments

While CDs were still fighting for market share against cassettes, and gaming consoles were just starting to switch over to CD from cartridge storage, optical media companies were already thinking ahead. Only two years after the introduction of the original PlayStation, the DVD Forum had introduced the DVD-RAM standard: 2.58 GB per side of a disc in a protective caddy. The killer feature? Essentially unlimited re-writeability. In a DVD drive that supports DVD-RAM, they act more like removable hard drive platters. You can even see hard sectors etched into the media at the time of manufacture, giving DVD-RAM its very recognizable pattern.

At the time, floppy drives were still popular, and CD-ROM drives were increasingly available pre-installed in new computers. Having what amounted to a hard drive platter with a total of 5 GB per disc should have been a killer feature for consumers. Magneto-optical drives were still very expensive, and by 1998 were only 1.3 GB in size. DVD-RAM had the same verify-after-write data integrity feature that magneto-optical drives were known for, but with larger capacity, and after the introduction of 4.7 GB size discs, no caddy was required.

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DIY Rabbit R1 Clone Could Be Neat With More Hardware

August 13, 2024 by 4 Comments

The Teenage Engineering badging usually appears on some cool gear that almost always costs a great deal of money. One such example is the Rabbit R1, an AI-powered personal assistant that retails for $199. It was also revealed that it’s basically a small device running a simple Android app. That raises the question — could build your own dupe for $20? That’s what [Thomas the Maker] did.

Meet Rappit. It’s basically [Thomas]’s take on an AI friend that doesn’t break the bank. It runs on a Raspberry Pi Zero 2W, which has the benefit of integrated wireless connectivity on board. It’s powered by rechargeable AA batteries or a USB power bank to keep things simple. [Thomas] then wrapped it all up in a cute 3D printed enclosure to give it some charm.

It’s software that makes the Rappit what it is. Rather than including a screen, microphone, or speakers on the device itself, [Thomas] interacts with the Pi-based device via smartphone. It makes it a less convincing dupe of the self-contained Rabbit R1, but the basic concept is the same. [Thomas] can make queries of the Rappit via a simple Android or iOS app he created called “Comfyspace,” and the Rappit responds with the aid of Google’s Gemini AI.

If you’re really trying to duplicate the trend of AI assistants, you really need standalone hardware. To that end, the Rappit design could really benefit from a screen, microphone, speaker, and speech synth. Honestly, though, that would only take you a few hours extra work compared to what [Thomas] has already done here. As it is, [Thomas] could simply throw away the Raspberry Pi and just use the smartphone with Gemini directly, right? But he chose this route of using the smartphone as an interface to keep costs down by minimizing hardware outlay.

If you want a real Rabbit R1, you can order one here. We’ve discussed controversy around the device before, too. Video after the break.

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