A 3D Printed Marble Clock, But It’s Scrolling Text

October 25, 2026 by No comments

With the topic of marble clocks having been quite well explored at this point, it raises the question of how easy it would be to take the basic principle and create a text display using black and white marbles. As [Ivan Miranda] found out in a recent marble text scroller project, this is far from easy.

The reason why a scrolling text display was picked comes down to not wanting to be limited to a fixed number of digits. This resulted in a round wheel design, with inner steel ball bearings and a stepper motor on both the wheel and an inner selector mechanism. These respectively align the marble channels and pick the right color of marbles to be dropped into any of the wheel’s slots, creating the right sequence of marbles for the target text.

Perhaps the most amazing thing about it is that it’s an absolutely massive structure, yet it’s all 3D printed and bolted together. It took a number of trial-and-error cycles, and debugging issues like the IR sensors getting confused by daylight, but it now mostly seems to work all right.

There are still some remaining issues, such as having to manually home the wheel before starting, and the ratio of black vs white marbles can cause unexpected gaps in the final text. Despite this the text is quite legible and definitely infinite.

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Mesh Network Telephony Over Bluetooth On Android Phones

October 25, 2026 by 4 Comments

Telephony is a bit of a mixed bag. On the one hand, being able to talk to people in far off places is kind of neat, at least in theory. On the other hand, you’re usually reliant on a centralized network, which isn’t ideal to the mindset of most hackers.[Gautam]’s MeshLive project deals with that last one, offering a decentralized mesh network solution based on Bluetooth for Android phones that can handle both voice and video.

Rather than relying on dedicated hardware, this particular mesh piggybacks on your phone, and exists only as an Android application. Calls are end-to-end encrypted for both voice and video — though two-way video calling is still experimental. More testing has gone into video broadcasting, where a stream goes out one-way. The capability is available for voice, as well.

Each user has a unique identifier that can be scanned to create contacts, but it isn’t otherwise clearly identifiable to everybody. You’ll only appear with a random name that changes every 15 minutes to other users in range who aren’t your contacts. Range is of course the Achilles heel of this project, since it’s using the Bluetooth hardware of ordinary smartphones. It’s possible to extend the range of Bluetooth significantly with the right hardware, but we imagine most folks aren’t carrying directional antennas around with them. While every phone does forward the signal to as many others as it can, it can only do so for about 20 meters.

Of course LoRa remains the protocol of choice for mesh networking, though it’s normally used for text messages only. We have seen voice packets over LoRa, but anything LoRa requires dedicated hardware while this only requires an app.

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Simple, Reliable RF Remote Control

October 25, 2026 by 11 Comments

Some of the first remote controls available to consumers used sound, visible light, or even just wires to communicate with their parent device. It was many years between these first rudimentary remotes before they standardized around infrared or RF signaling. Even then it was a while before remote controls were reliable enough to not have to think about anymore. They’ve gotten so good now that there are small modules available that let us quickly build these devices to perform all manner of tasks.

[Igor Brichkov] is demonstrating this project because his garage door remote control suddenly stopped working. The RF receiver and transmitter circuits are readily available and inexpensive, but they need some support circuitry to work properly. The transmitter is paired with an encoder which is provided a binary code by wiring various pins to power and ground. This “code” is sent to the receiver which has a decoder and listens for that specific code. When the codes match it changes the state of one of its pins, which is used in this case to short the garage door’s remote terminals and signal it to open the door.

Although the resulting handheld remote with its single button looks a bit like something from 1950s science-fiction, it’s an effective solution. Especially when compared to possibly trying to reprogram a proprietary remote, find one from a company that doesn’t exist anymore, or rebuild one that operates on a bizarre frequency. With access to the physical hardware, it turns out a lot of things are controlled by just shorting pins together, and anything can do that from wires to RF transmitters.

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Four black plastic devices, two with a black, stubby antenna, sit on a blue cutting mat with white guidelines. There is also a PCB and a couple grey-ish clips in the assortment. One of the devices is open, showing another PCB with various components including a GPS antenna and LoRa radio. A silhouette of a dog is screen printed next to the text "LIA" on the PCBs, and the same text and image is present in the shell of the device in the top center.

Meshtastic Pet Tracking

October 25, 2026 by 9 Comments

Most commercial pet trackers require a subscription or network connection to function. [Jon G Aguado] wanted a better way and designed LIA, a Meshtastic collar tracker.

LIA uses a custom PCB containing a ESP32-S3, LoRa radio, GPS/GNSS receiver, and a charge controller for the 18650 or 5023450 pouch Li-ion cell powering the device. Everything fits inside a 3D printed enclosure, and the device is charged via a magnetic 4-pin USB pogo connector to increase weather resistance.

One of the neat features of this particular tracker is that [Aguado] gave it two different power modes. High power gets a location fix every 30 seconds and has a pair of bright LEDs for visual assistance, low power only gets a fix every minute or so, and it can also be set to off, which is something we wish more device manufacturers remembered should be an option.

We hope anyone planning on using Meshtastic and LoRa in the US is aware of the issues surrounding FCC compliance, and if you want to track your pet another way, maybe KineFox is an option?

An Analog TV Station For Anyone

October 25, 2026 by 22 Comments

If you’re a collector of older TVs, you’re probably facing the problem in some form of having no transmissions to tune in to. With many sets you can use a SCART or other A/V input, but nothing beats using the thing as it was intended. [BorisDigital] had exactly this problem, and since he worked in a TV transmitter control room in the 1990s, he’s made a small TV station that looks and operates like the real thing.

It’s a 10 inch rack stuffed with goodies, each of which replicates the function of a piece of broadcast gear which would have cost a small fortune back in the day. At the top is a transmitter, a relatively inexpensive board from China. Below it a clock and audio monitor powered by a Pi Pico, then a vectorscope, waveform monitor, and monitor powered by a set of Pi 5s with USB video digitisers, a pair of SD card video record/play units — yet more Raspberry Pi — and at the bottom, an automatic scheduler powered by another fruity board from Cambridge. If you’re not into TV the construction may be worth a second look. Those neat looking rack front panels are 3D printed with different filaments for the lettering, and are both robust and stylish. We can already see how this could be used in our work.

We miss analogue TV, partly because it was a wonderfully intricate technology that, beautifully, just worked. it’s a few years now since we reported on the last gasp of analogue TV in the USA, about a decade after it was turned off where this is being written.

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Pushing Bluetooth Out To 12 Kilometers

October 24, 2026 by 21 Comments

Bluetooth is a short-range protocol that’s great for peripherals and finding your keys, but it’s limited range is mainly a product of how it’s usually implemented. A recent video from [nktbuilds] demonstrates this by extending its range out to 12 kilometers, or around 7.5 miles.

The secret is twofold: one is the antenna, a parabolic unit that captures far more than the dinky dipole in your phone. The other is a very sensitive receiver with a much lower noise floor. What you won’t see here is any extra power than you get stock out of one of those generic coin-sized Bluetooth tracker tags. It’s kind of obvious, in retrospect: grab more signal, lower your noise floor, and get a better result. Still, it certainly wasn’t obvious it would work out to 1200 m, and it’s an impressive feat by [nktbuilds]. We’re going to have to keep it in mind next time we lose our keys.

Of course this doesn’t mean you should jump to Bluetooth for distance communications. You’re still better off sticking with something like LoRA for that, especially since it’s good to hundreds of miles if you can get line-of-sight — or even tens of thousands with the right setup.

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Remembering The Weirdest Nintendo DSi Accessory

October 24, 2026 by 2 Comments

The Nintendo DSi was released in November 2008, and boasted a new feature not formerly seen on the brand’s handhelds—it had two cameras, inside and outside. It let the console take photos, a feature rather fitting given it was an era in which phone cameras had become the norm. Only, it wasn’t so good out of the box. However, [gavff] recently found an accessory from way back when that aimed to make the DSi’s camera somewhat more capable.

For some reason, the console accessories company Nyko decided that that the Nintendo DSi deserved an 8x optical zoom lens. Never mind that the console’s cameras were limited to a resolution of just 640 x 480 pixels, it was deemed important that the handheld have the ability to capture images of things that were somewhat farther away. The lens mounted to a specially-designed case that fit around the original DSi’s shell. It’s not particularly clear what the intended use case was, but if you wanted to expand the capability of your DSi camera, this was one way to do it. You could get some pretty sharp photos if you knew what you were doing, as [gavff] demonstrates in the video.

The video then takes things farther, putting an even larger, sillier telescopic camera lens on the DSi. [gavff] used it to capture a photo of the Moon, with the benefit that unlike modern smartphones, there’s no AI faking the results. The video also touches on the goofy Mad Catz flash accessory that used the DSi’s charge port.

We love seeing silly lenses on cameras that were never supposed to host them. Also, isn’t it wonderful that our ancient “Nintendo DS Hacks” category is getting some love again after all this time? We’ve actually published a bunch of DS hacks this year.

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