Lynx-R1 Headset Makers Release 6DoF SLAM Solution As Open Source

August 27, 2025 by 8 Comments

Some readers may recall the Lynx-R1 headset — it was conceived as an Android virtual reality (VR) and mixed reality (MR) headset with built-in hand tracking, designed to be open where others were closed, allowing developers and users access to inner workings in defiance of walled gardens. It looked very promising, with features rivaling (or surpassing) those of its contemporaries.

Founder [Stan Larroque] recently announced that Lynx’s 6DoF SLAM (simultaneous location and mapping) solution has been released as open source. ORB-SLAM3, modified for Android-based hardware (GitHub repository), takes in camera images and outputs a 6DoF pose, and does so effectively in real-time. The repository contains some added details as well as a demo application that can run on the Lynx-R1 headset.

The unusual optics are memorable. (Hands-on Lynx-R1 by Antony Vitillo)

As a headset the Lynx-R1 had a number of intriguing elements. The unusual optics, the flip-up design, and built-in hand tracking were impressive for its time, as was the high-quality mixed reality pass-through. That last feature refers to the headset using its external cameras as inputs to let the user see the real world, but with the ability to have virtual elements displayed and apparently anchored to real-world locations. Doing this depends heavily on the headset being able to track its position in the real world with both high accuracy and low latency, and this is what ORB-SLAM3 provides.

A successful crowdfunding campaign for the Lynx-R1 in 2021 showed that a significant number of people were on board with what Lynx was offering, but developing brand new consumer hardware is a challenging road for many reasons unrelated to developing the actual thing. There was a hands-on at a trade show in 2021 and units were originally intended to ship out in 2022, but sadly that didn’t happen. Units still occasionally trickle out to backers and pre-orders according to the unofficial Discord, but it’s safe to say things didn’t really go as planned for the R1.

It remains a genuinely noteworthy piece of hardware, especially considering it was not a product of one of the tech giants. If we manage to get our hands on one of them, we’ll certainly give you a good look at it.

A preproduction U1 sitting on a workbench

A Tool-changing 3D Printer For The Masses

August 27, 2025 by 26 Comments

Modern multi-material printers certainly have their advantages, but all that purging has a way to add up to oodles of waste. Tool-changing printers offer a way to do multi-material prints without the purge waste, but at the cost of complexity. Plastic’s cheap, though, so the logic has been that you could never save enough on materials cost to make up for the added capital cost of a tool-changer — that is, until now.

Currently active on Kickstarter, the Snapmaker U1 promises to change that equation. [Albert] got his hands on a pre-production prototype for a review on 247Printing, and what we see looks promising.

The printer features the ubiquitous 235 mm x 235 mm bed size — pretty much the standard for a printer these days, but quite a lot smaller than the bed of what’s arguably the machine’s closest competition, the tool-changing Prusa XL. On the other hand, at under one thousand US dollars, it’s one quarter the price of Prusa’s top of the line offering. Compared to the XL, it’s faster in every operation, from heating the bed and nozzle to actual printing and even head swapping. That said, as you’d expect from Prusa, the XL comes dialed-in for perfect prints in a way that Snapmaker doesn’t manage — particularly for TPU. You’re also limited to four tool heads, compared to the five supported by the Prusa XL.

The U1 is also faster in multi-material than its price-equivalent competitors from Bambu Lab, up to two to three times shorter print times, depending on the print. It’s worth noting that the actual print speed is comparable, but the Snapmaker takes the lead when you factor in all the time wasted purging and changing filaments.

The assisted spool loading on the sides of the machine uses RFID tags to automatically track the colour and material of Snapmaker filament. That feature seems to take a certain inspiration from the Bambu Labs Mini-AMS, but it is an area [Albert] identifies as needing particular attention from Snapmaker. In the beta configuration he got his hands on, it only loads filament about 50% of the time. One can only imagine the final production models will do better than that!

In spite of that, [Albert] says he’s backing the Kickstarter. Given Snapmaker is an established company — we featured an earlier Snapmaker CNC/Printer/Laser combo machine back in 2021— that’s less of a risk than it could be.

Continue reading “A Tool-changing 3D Printer For The Masses” →

A view of the schematics for each major component.

Simulating The Commodore PET

August 26, 2025 by 2 Comments

Over on his blog our hacker [cpt_tom] shows us how to simulate the hardware for a Commodore PET. Two of them in fact, one with static RAM and the other with dynamic RAM.

This project is serious business. The simulation environment used is Digital. Digital is a digital logic designer and circuit simulator designed for educational purposes. It’s a Java program that runs under the JVM. It deals in .dig files which are XML files that represent the details of the simulated hardware components. You don’t need to write the XML files by hand, there is a GUI for that. Continue reading “Simulating The Commodore PET” →

Google Will Require Developer Verification Even For Sideloading

August 26, 2025 by 114 Comments

Do you like writing software for Android, perhaps even sideload the occasional APK onto your Android device? In that case some big changes are heading your way, with Google announcing that they will soon require developer verification for all applications installed on certified Android devices – meaning basically every mainstream device. Those of us who have distributed Android apps via the Google app store will have noticed this change already, with developer verification in the form of sending in a scan of your government ID now mandatory, along with providing your contact information.

What this latest change thus effectively seems to imply is that workarounds like sideloading or using alternative app stores, like F-Droid, will no longer suffice to escape these verification demands. According to the Google blog post, these changes will be trialed starting in October of 2025, with developer verification becoming ‘available’ to all developers in March of 2026, followed by Google-blessed Android devices in Brazil, Indonesia, Thailand and Singapore becoming the first to require this verification starting in September of 2026.

Google expects that this system will be rolled out globally starting in 2027, meaning that every Google-blessed Android device will maintain a whitelist of ‘verified developers’, not unlike the locked-down Apple mobile ecosystem. Although Google’s claim is that this is for ‘security’, it does not prevent the regular practice of scammers buying up existing – verified – developer accounts, nor does it harden Android against unscrupulous apps. More likely is that this will wipe out Android as an actual alternative to Apple’s mobile OS offerings, especially for the hobbyist and open source developer.

Avocado Harvester Is A Cut Above

August 26, 2025 by 7 Comments

For a farmer or gardener, fruit trees offer a way to make food (and sometimes money) with a minimum of effort, especially when compared to growing annual vegetables. Mature trees can be fairly self-sufficient, and may only need to be pruned once a year if at all. But getting the fruit down from these heights can be a challenge, even if it is on average less work than managing vegetable crops. [Kladrie] created this avocado snipper to help with the harvest of this crop.

Compounding the problem for avocados, even compared to other types of fruit, is their inscrutable ripeness schedule. Some have suggested that cutting the avocados out of the trees rather than pulling them is a way to help solve this issue as well, so [Kladrie] modified a pair of standard garden shears to mount on top of a long pole. A string is passed through the handle so that the user can operate them from the ground, and a small basket catches the fruit before it can plummet to the Earth. A 3D-printed guide helps ensure that the operator can reliable snip the avocados off of the tree on the first try without having to flail about with the pole and hope for the best, and the part holds the basket to the pole as well.

For those living in more northern climates, this design is similar to many tools made for harvesting apples, but the addition of the guide solves a lot of the problems these tools can have which is largely that it’s easy to miss the stems on the first try. Another problem with pulling the fruits off the tree, regardless of species, is that they can sometimes fling off of their branches in unpredictable ways which the snipping tool solves as well. Although it might not work well for avocados, if you end up using this tool for apples we also have a suggestion for what to do with them next.

Battery Repair By Reverse Engineering

August 26, 2025 by 28 Comments

Ryobi is not exactly the Cadillac of cordless tools, but one still has certain expectations when buying a product. For most of us “don’t randomly stop working” is on the list. Ryobi 18-volt battery packs don’t always meet that expectation, but fortunately for the rest of us [Badar Jahangir Kayani] took matters into his own hands and reverse-engineered the pack to find all the common faults– and how to fix them.

[Badar]’s work was specifically on the Ryobi PBP005 18-volt battery packs. He’s reproduced the schematic for them and given a fairly comprehensive troubleshooting guide on his blog. The most common issue (65%) with the large number of batteries he tested had nothing to do with the cells or the circuit, but was the result of some sort of firmware lock.

It isn’t totally clear what caused the firmware to lock the batteries in these cases. We agree with [Badar] that it is probably some kind of glitch in a safety routine. Regardless, if you have one of these batteries that won’t charge and exhibits the characteristic flash pattern (flashing once, then again four times when pushing the battery test button), [Badar] has the fix for you. He actually has the written up the fix for a few flash patterns, but the firmware lockout is the one that needed the most work.

[Badar] took the time to find the J-tag pins hidden on the board, and flash the firmware from the NXP micro-controller that runs the show. Having done that, some snooping and comparison between bricked and working batteries found a single byte difference at a specific hex address. Writing the byte to zero, and refreshing the firmware results in batteries as good as new. At least as good as they were before the firmware lock-down kicked in, anyway.

He also discusses how to deal with unbalanced packs, dead diodes, and more. Thanks to the magic of buying a lot of dead packs on e-Bay, [Badar] was able to tally up the various failure modes; the firmware lockout discussed above was by far the majority of them, at 65%. [Badar]’s work is both comprehensive and impressive, and his blog is worth checking out even if you don’t use the green brand’s batteries. We’ve also embedded his video below if you’d rather watch than read and/or want to help out [Badar] get pennies from YouTube monetization. We really do have to give kudos for providing such a good write up along with the video.

This isn’t the first attempt we’ve seen at tearing into Ryobi batteries. When they’re working, the cheap packs are an excellent source of power for everything from CPap machines to electric bicycles.

Thanks to [Badar] for the tip.

Continue reading “Battery Repair By Reverse Engineering” →

Automated Brewing

August 26, 2025 by 6 Comments

There’s little more to making alcoholic beverages than sugar, water, yeast, and time. Of course those with more refined or less utilitarian tastes may want to invest a bit more care and effort into making their concoctions. For beer making especially this can be a very involved task, but [Fieldman] has come up with a machine that helps automate the process and take away some of the tedium.

[Fieldman] has been making beers in relatively small eight-liter batches for a while now, and although it’s smaller than a lot of home brewers, it lends itself perfectly to automation. Rather than use a gas stove for a larger boil this process is done on a large hot plate, which is much more easily controlled by a microcontroller. The system uses an ESP32 for temperature control, and it also runs a paddle stirrer and controls a screen which lets the brewer know when it’s time to add ingredients or take the next step in the process. Various beers can be programmed in, and the touchscreen makes it easy to know at a glance what’s going on.

For a setup of this size this is a perfect way to take away some of the hassle of beer brewing like making sure the stove didn’t accidentally get too hot or making sure it’s adequately stirred for the large number of hours it might take to brew, but it still leaves the brewer in charge for the important steps.

Beer brewing is a hobby with a lot of rabbit holes to jump down, and it can get as complicated as you like. Just take a look at this larger brewery setup that automates more tasks on a much larger scale.

Continue reading “Automated Brewing” →