Bicycle Tows 15,000 Pounds

January 4, 2026 by 1 Comment

An old joke in physics is that of the “spherical cow”, poking fun at some of the assumptions physicists make when tackling a new problem. Making the problem simple like this can help make its fundamentals easier to understand, but when applying these assumptions to real-world problems these assumptions are quickly challenged. Which is what happened when [Seth] from Berm Peak attempted to tow a huge trailer with a bicycle — while in theory the bike just needs a big enough gear ratio he quickly found other problems with this setup that had to be solved.

[Seth] decided on a tandem bike for this build. Not only does the second rider add power, but the longer wheelbase makes it less likely that the tongue weight of the trailer will lift the front wheel off the ground. It was modified with a Class 3 trailer hitch, as well as a battery to activate the electric trailer brakes in case of an emergency. But after hooking the trailer up the first time the problems started cropping up. At such a high gear ratio the bike is very slow and hard to keep on a straight line. Some large, custom training wheels were added between the riders to keep it stable, but even then the huge weight still caused problems with the chain and even damaged the bike’s freehub at one point.

Eventually, though, [Berm Peak] was able to flat tow a Ford F-150 Lightning pulling a trailer a few yards up a hill, at least demonstrating this proof of concept. It might be the absolute most a bicycle can tow without help from an electric motor, although real-world applications for something like this are likely a bit limited. He’s been doing some other bicycle-based projects with more utility lately, including a few where he brings abandoned rental e-bikes back to life by removing proprietary components.

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Print Pixel Art To A Floppy Disk

January 4, 2026 by No comments

Here at Hackaday we love floppy disks. While they are by no means a practical or useful means of storing data in the age of solid state storage, there is something special about the little floppy disc of magnetic film inside that iconic plastic case. That’s why we were so excited to see the tool [dbalsom] developed for printing pixel art in a floppy’s track timing diagrams!

Floppy timing diagrams are usually used to analyze the quality of an individual disk. It represents flux transitions within the a single floppy tack as a 2D graph. But it’s also perfectly possible to “paint” images on a floppy this way. Granted, you can’t see these images without printing out a timing diagram, but if your painting images onto a floppy, that’s probably the point.

This is where pbm2track tool comes in handy! It takes bitmap images and encodes them onto floppy emulators, or actual floppies. The results are quite excellent, with near-perfect recreation in floppy graphical views. The results on real floppies are also recognizable as the original image. The concept is similar to a previous tool [dbalsom] created, PNG2disk

If you too love the nearly forgotten physical likeness of the save button, make sure to check out this modern Linux on a floppy hack next!

Thanks [gloriouscow] for the tip!

Modifying A QingPing Air Quality Monitor For Local MQTT Access

January 4, 2026 by 2 Comments

The QingPing Air Quality Monitor 2 is an Android-based device that not only features a touch screen with the current air quality statistics of the room, but also includes an MQTT interface that normally is used in combination with the QingPing mobile app and the Xiaomi IoT ecosystem. Changing it to report to a local MQTT server instead for integration with e.g. Home Assistant can be done in an official way that still requires creating a cloud account, or you can just do it yourself via an ADB shell and some file modifications as [ea] has done.

By default these devices do not enumerate when you connect a computer to their USB-C port, but that’s easily resolved by enabling Android’s developer mode. This involves seven taps on the Device Name line in the About section of settings. After this you can enter Developer Options to toggle on Debug Mode and Adbd Debugging, which creates the option to connect to the device via USB with ADB and open up a shell with adb shell.

From there you can shoot off the QingSnow2 app and the watchdog.sh that’s running in the background, disable IPv6 and edit /etc/host to redirect all the standard cloud server calls to a local server. Apparently there is even SSH access at this point, with root access and password rockchip. The MQTT configuration is found under /data/etc/ in settings.ini, which is used by the QingPing app, so editing redirects all that.

Of course, the device also queries a remote server for weather data for your location, so if you modify this you have to provide a proxy, which [ea] did with a simple MQTT server that’s found along with other files on the GitHub project page.

Sleeping Rough In Alaska With A USPS Cargo Bike

January 4, 2026 by 16 Comments

Out of all 49 beautiful US states (plus New Jersey), the one you’d probably least want to camp outside in during the winter is arguably Alaska. If you were to spend a night camping out in the Alaskan winter, your first choice of shelter almost certainly wouldn’t be a USPS electric cargo trike, but over on YouTube [Matt Spears] shows that it’s not that hard to make a lovely little camper out of the mail bike. 

We’re not sure how much use these sorts of cargo trikes get in Alaska, but [Matt] seems to have acquired this one surplus after an entirely-predictable crash took one of the mirrors off. A delta configuration trike — single wheel in front — is tippy at the best of times, but the high center of gravity you’d get from a loading the rear with mail just makes it worse. That evidently did not deter the United States Postal Service, and it didn’t deter [Matt] either.

His conversion is rather minimal: to turn the cargo compartment into a camper, he only adds a few lights, a latch on the inside of the rear door, and a wood-burning stove for heat. Rather than have heavy insulation shrink the already-small cargo compartment, [Matt] opts to insulate himself with a pile of warm sleeping bags. Some zip-tie tire chains even let him get the bike moving (slowly) in a winter storm that he claims got his truck stuck.

While it might not be a practical winter vehicle, at least on un-plowed mountain roads, starting with an electric-assist cargo trike Uncle Sam already paid for represented a huge cost and time savings vs starting from scratch like this teardrop bike camper we featured a while back. While not as luxurious, it seems more practical for off-roading than another electric RV we’ve seen.

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Ray Marching In Excel

January 4, 2026 by 2 Comments

3D graphics are made up of little more then very complicated math. With enough time, you could probably compute a ray marching by hand. Or, you could set up Excel to do it for you!

Ray marching is a form of ray tracing, where a ray is stepped along based on how close it is to the nearest surface. By taking advantage of signed distance functions, such an algorithm can be quite effective, and in some instances much more efficient then traditional ray marching algorithms. But the fact that ray marching is so mathematically well defined is probably why [ExcelTABLE] used it to make a ray traced game in Excel.

Under the hood, the ray marching works by casting a ray out from the camera and measuring its distance from a set of three dimensional functions. If that distance is below a certain value, this is considered a surface hit. On surface hits, a simple normal shader computes pixel brightness. This is then rendered out by variable formatting in the cells of the spreadsheet.

For those of you following along at home, the tutorial should work just fine in any modern spreadsheet software including Google Sheets and LibreOffice Calc. It also provides a great explanation of the math and concepts of ray marching, so is worth a read regardless your opinions on Excel’s status as a so-called “programming language.”

This is not the first time we have come across a ray tracing tutorial. If computer graphics are your thing, make sure to check out this ray tracing in a weekend tutorial next!

Thanks [Niklas] for the tip!

The Nintendo 64DD, an N64 add-on released only in Japan in 1999.

Exploring Nintendo 64DD Code Remnants In Ocarina Of Time

January 4, 2026 by 13 Comments

What if you took a Nintendo 64 cartridge-based game and allowed it to also use a large capacity magnetic disc format alongside it? This was the premise of the Nintendo 64DD peripheral, and the topic of a recent video by [Skawo] in which an archaeological code dig is performed to see what traces of the abandoned product may remain.

The 64DD slots into the bottom of the console where the peripheral connector is located, following which the console can read and write the magnetic discs of the 64DD. At 64 MB it matched the cartridge in storage capacity, while also being writable unlike cartridges or CDs. It followed on previous formats like the Famicom Disk System.

For 1998’s Game of the Year title The Legend of Zelda: Ocarina of Time such a 64DD-based expansion was worked on for a while before being cancelled along with the 64DD. With this Zelda game now decompiled, its source code has shown to be still full of 64DD-related code that [Skawo] takes us through in the video.

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Are We Ready For AR Smart Glasses Yet?

January 4, 2026 by 49 Comments

In a recent article from IEEE Spectrum, [Alfred Poor] asks the question what do consumers really want in smart glasses? And are you finally ready to hang a computer screen on your face?

[Alfred] says that since Google Glass was introduced in 2012, smart glasses haven’t yet found their compelling use-case. Apparently it looks like while virtual reality (VR) might be out, augmented reality (AR) might be in. And of course now we have higher levels of “AI” in the mix, whatever that means.

According to the article in the present day there are two competing visions of what smart glasses might be: we have One Pro from Xreal in Beijing, and AI Glasses from Halliday in Singapore, each representing different design concepts evolving in today’s market. The article goes into further detail. The video below the break is promotional material from Halliday showing people’s reactions to their AI Glasses product.

[Alfred] talks with Louis Rosenberg, CEO and chief scientist of Unanimous AI, who says he believes “that within five years, immersive AI-powered glasses will replace the smartphone as the primary mobile device in our digital lives.” Predicting the future is hard, but what do you think? Sound off in the comments!

All in all smart glasses remain a hot topic. If you’d like to read more check out our recent articles Making Glasses That Detect Smartglasses and Mentra Brings Open Smart Glasses OS With Cross-Compat.

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