SmallTV Hacking With Surprisingly Little Fuss

We’ve seen the GeekMagic SmallTV line of devices before — these cheap gadgets combine a microcontroller and a display in a little plastic case that can be used to show the time or weather. Powered by either an ESP8266 or an ESP32, the things could easily pass for a hobby build if it wasn’t for their professionally produced enclosures. In fact, we wouldn’t be surprised if GeekMagic lifted the idea from an existing DIY project.

As you might expect we’ve seen several hacks for these devices already, which usually involves replacing the stock firmware. But this latest approach is unique in that you don’t need to mess with the stock software, nor do you need to break out the soldering iron. By leveraging a built-in photo viewer function of the SmallTV [Yongha Kim] shows how you can get the gadget to display pretty much whatever you want.

The trick here is that the image is being generated by a machine on the network, say your desktop or server, and being pushed over to the SmallTV over HTTP. In this example the image is being generated in Python with the Pillow library, and [Yongha] has it showing Claude and Codex usage data, but you could really approach this however you wish.

All you need to do is create a 240×240 image and shoot it over to the device, so you’re free to come up with whatever sort of visuals you’d like. It even supports GIF if you’d like to work animation into it. The content can of course be whatever information you’re interested in showing, and it can be generated by whatever programming language or tool you’re most comfortable with. It’s a fascinating proof of concept, and now that the method has been demonstrated we’re interested to see where the community can take it.

If this all sounds a little too easy for your tastes, don’t worry. There’s a plenty deep rabbit hole you can dive into should you elect to replace the device’s firmware entirely.

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Hackaday Links: October 3, 2026

If you’re interested in aerospace, there’s an excellent chance you’ve heard the rumor that NASA is trying to get its SR-71 flying again. Or at the very least, they are interested in what exactly it would take to bring the iconic Mach 3+ spy plane back online.

The story started a couple of weeks ago when NASA Administrator Jared Isaacman announced the agency would be reinvesting in their famed “X-Plane” experimental aircraft program in an effort to get “back in the business of flying high and fast again.” Not long after, keen-eyed observers noted that the SR-71 that had been sitting on the tarmac at the Armstrong Flight Research Center in California had been moved to an unknown location. Several individuals who worked on the plane while it was operational have since claimed NASA representatives contacted them about potentially refurbishing it.

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Electronic Busy Board Is Fun For Kids and Hackers

While you may not be familiar with the term “busy board”, you’ve almost certainly seen one. It’s the sort of toy with a bunch of buttons, switches, and of course LEDs, that are designed to keep young children entertained. As it so buttons, switches, buttons, and LEDs also keep hardware hackers entertained — doubly so if they are the ones designing said busy board in the first place.

That’s where we find [Andy], or should we say, [Uncle Andrew]. Last Christmas he decided to scratch build an electronic busy board for his nephew, and while it might not be a terribly complex piece of kit from a technical standpoint, it’s a fantastic multidisciplinary project in that it’s really equal parts hardware and software. While it would surely be possible to implement a gadget like this entirely in hardware, [Andy] took the modern hobbyist approach of offloading some of the task to a collection of carefully arranged ones and zeros.

In the write-up, [Andy] goes over the decisions he made while designing and building the device. This ranges from the extra effort put in to keep the PCB down to two layers and the logic behind LED multiplexing. This extends right into the software aspect of the project, with a surprisingly deep explanation of how the code uses timers and interrupts to run the show as efficiently as possible, maximizing the run time of the PIC18F67K40 microcontroller on a trio of AAA batteries.

It’s a fun read about a low-stakes project that’s made all the better by the personal touch. Just like the kids of makers and hardware hackers, [Andy]’s nephew is a lucky to have somebody like this in his life.

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Gardening With…OpenSCAD?

Unless it’s automated or using some other form of high-tech trickery, a vegetable garden isn’t exactly the sort of thing you’d expect to see on Hackaday. Be that as it may, the bountiful crop of peppers [Mihai Oltean] grew on the side of his house was done the old fashioned way, with nary a transistor in sight. So what’s the catch?

Well, in this case, it’s more about the journey than the end result. The produce sprouting in [Mihai]’s garden may be common enough, but the method in which he designed the garden itself is worth a closer look. To our knowledge, it’s the first time somebody sat down and wrote out all the code to generate a 3D model of a vertical garden in OpenSCAD.

Usually, we see OpenSCAD used to produce design files for 3D printing or occasionally 2D CNC operations. But that’s not what’s happening here. The goal was to simply plan out how all the parts of the system would come together, and [Mihai] felt comfortable tackling it in the code-centric workflow offered by OpenSCAD. We know the feeling well.

Though the code isn’t necessarily being used to produce parts for manufacture, [Mihai] does bring in a bunch of virtual components to stand in for their corporeal counterparts. We’re partial to using a parts library such as NopSCADlib for this kind of thing, but from the looks of the GitHub repo, [Mihai] decided to implement his own versions of the screws, nuts, washers, and sections of metal extrusion used to construct the garden wall.

We recently covered the advantages of “building” a complex multi-part project like a CNC control cabinet virtually in your CAD tool of choice before bending metal on the real thing. This project is a fantastic example of that concept, as it shows that the technique isn’t limited to electronic components.

After Decades, NASA May Finally Replace Mars Relays

We’ve yet to find any definitive evidence that there’s biological life on present-day Mars, but to say it’s a dead planet isn’t exactly accurate. Since the first Viking lander touched down in 1976, a revolving cast of humanity’s robotic envoys have worked on and around the Red Planet — and as access to space becomes cheaper and more routine, the mechatronic population of Mars will continue to grow.

Given the number of landers, rovers, and orbiting spacecraft that have been sent to study Mars over the last 50 years, you might be surprised to find that the communications systems in place to transmit all that critical scientific data back to Earth aren’t nearly as robust as you’d think. While it’s understandable that the first craft to arrive at Mars had to operate in isolation, even the flagship Perseverance and Curiosity rovers carry their own high-gain radio systems so they can communicate directly with Earth. Given the incredible premium put on the mass of an interplanetary craft, each mission that needs to bring along its own link back to Earth effectively reduces its payload of much scientific equipment.

It’s not that satellites in orbit around the planet aren’t used to relay signals between Martian ground assets and their controllers back on Earth. In fact these relay links are used extensively for bandwidth-intensive tasks such as image transfers. But it’s also true that the craft currently available to act as intermediaries between the two planets aren’t terribly well suited to the task. The current fleet of Mars orbiters were conceived primary as research vehicles, and so every decision regarding their design and positioning around the planet was made with that goal in mind. What relatively limited capability they do have as communication relays is further hindered by the age of their hardware.

But after decades of false starts and shifting budgets, NASA is closer than ever to finally establishing the Mars Telecommunications Network, a dedicated high-bandwidth communication relay that will ensure current and future missions always have a way to phone home.

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Reconstructing Device Firmware From SPI Reads

If you wanted to extract the firmware from a mystery device, you might pull the flash chip out of it and toss it into a reader. But if you only had one chance to get it right and couldn’t risk damaging the device in the process, physically removing the chip may seem much less attractive. Reading the chip in-circuit failed — because of course it did — so what does that leave?

Well, if you follow the example of [Matthew “wrongbaud” Alt], the next tool you reach for might be a logic analyzer. In a recent write-up, [wrongbaud] explains the process of identifying, capturing, and ultimately decoding the SPI read operations used to load the firmware from a common W25Q-series flash chip at boot time. He notes it’s not a perfect solution, as in the end you’ll only be able to sniff out what the CPU actually reads, not necessarily the entire contents of the chip, but it’s a big step in the right direction if you’re reverse engineering something in the dark.

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Audio Spectrum Analyzer On An ESP32 Display Board

A slick spectrum analyzer used to be the kind of thing that would have been tricky to include in a DIY project, but as [Mirko “mircemk” Pavleski] demonstrates, a modern microcontroller like the ESP32 can handle the task with nothing more than a display panel and a few passives.

This particular example is built around the CrowPanel 3.5, which combines the powerful microcontroller with a 480×320 touch screen LCD. But there’s nothing inherently special about the CrowPanel, and you could get similar results with whatever display you might have kicking around the parts bin — albeit potentially with some code changes to account for the different hardware.

Beyond the microcontroller and the display, all you need to recreate what [mircemk] has done here is a handful of passives to tame the incoming analog audio signal so it can be piped into one of the analog-to-digital converter (ADC) pins on the MCU.

This project is fairly simple, but if you’re looking for something a little more advanced from [mircemk], don’t worry. The more daring home players can try their hand at recreating this high-voltage X-ray machine made from an old TV vacuum tube.

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