Developing A Power Over Ethernet Stack Light

A common sight on factory floors, stack lights are used to indicate the status of machinery to anyone within visual range. But hackers have found out you can pick them up fairly cheap online, so we’ve started to see them used as indicators in slightly more mundane situations than they were originally intended for. [Tyler Ward] recently decided he wanted his build own network controlled stack light, and thought it would double as a great opportunity to dive into the world of Power Over Ethernet (PoE).

Now the easy way to do this would be to take the Raspberry Pi, attach the official PoE Hat to it, and toss it into a nice enclosure. Write some code that toggles the GPIO pins attached to the LEDs in the stack light, and call it a day. Would be done in an afternoon and you could be showing it off on Reddit by dinner time. But that’s not exactly what [Tyler] had in mind.

An early Arduino-based prototype.

He decided to take the scenic route and designed his own custom PCB that combines an Ethernet interface, PoE hardware, and the ESP32 into one compact unit. It’s no great secret that it only takes a few extra components to plug the ESP32 into the network rather than relying on WiFi, but it’s still not something we see done very often by hobbyists. Rarer still is seeing somebody roll their own PoE solution, but thanks to the in-depth documentation [Tyler] has provided for his circuit, that may change in the future.

On the software side [Tyler] has developed a firmware for the ESP32 that supports both Art-Net and RDM protocols, which are subsets of the larger DMX protocol. That means the controller should be compatible with existing software designed for controlling theatrical lighting systems. If you’d rather take a more direct approach, the firmware also sports a web interface and simple HTTP API to provide some additional flexibility.

While it’s exceptionally impressive, not everyone will need such a robust solution. If you just want a quick and easy way to fire up your stack light, a USB controlled relay and some Python can get you where you need to go.

2:3 Scale VT100 Terminal Gets Closer To Its Roots

When [Michael Gardi] finished his scaled down DEC VT100 replica a few months ago, he made it very clear that the project was only meant to look like a vintage terminal on the outside. A peek into the case revealed nothing more exotic than a Raspberry Pi running its default operating system, making the terminal just as well suited to emulating classic games as it was dialing into a remote system. But as any hacker knows, some projects end up developing a life of their own.

It started simply enough. The addition of an RS-232 Serial HAT to the Raspberry Pi meant that the 3D printed VT100 could actually operate as a serial terminal using software such as minicom. Then [Lars Brinkhoff] got involved. He loved the look of the printed VT100, and thought it deserved better than a generic terminal emulator. So he went ahead and started developing a custom terminal simulator for it to run.

Reliving those CRT glory days.

The idea here is that an an 8080 emulator actually runs an original VT100 firmware ROM, warts and all. It makes all the beeps and chirps you’d expect from the real hardware, and there’s even some OpenGL trickery used to mimic an old CRT display, complete with scan lines and a soft glow around characters.

Naturally the visual effects consume a fair amount of processing power, so [Lars] cautions that anything lower than the Pi 4 will likely experience slowdowns. Of course, nothing is stopping you from running the simulator on your desktop machine if you’re looking for that classic terminal experience.

Did this gorgeous recreation of the VT100 need to have a true serial interface or a simulator that recreates the unique menu system of the original? Not at all. Even without those additions, it blew us away when [Michael] first sent it in. But are we happy that these guys have put in the time to perfect this already stellar project? We think you already know the answer.

Custom Firmware Teaches USB Relay Board New Tricks

If you’re looking for a quick and easy way to control a few devices from your computer, a cheap USB relay board might be the ideal solution. These are fairly simple gadgets, consisting of little more than a microcontroller and a handful of relays. But that doesn’t mean there isn’t room for improvement, and as [Michał Słomkowski] recently demonstrated, flashing these boards with a custom firmware allows the user to modify their default functionality.

In his case, [Michał] wanted to build a power strip that would cut the power to any devices plugged into it once his computer went to sleep. Unfortunately, he couldn’t just check to see if there was 5 V on the line as his motherboard kept the USB ports powered up all the time. But with some modifications to the relay board’s firmware, he reasoned he should be able to detect if there was any USB activity by watching for the start-of-frame packet that goes out every millisecond when the bus is active.

Wiring up the ATtiny45 for flashing.

Now [Michał] isn’t claiming to be the first person to come up with a custom firmware for one of these boards, in fact, he credits an existing open source firmware project as an inspiration for his work. But he did create an entirely new GPLv3 firmware for these ATtiny45 powered devices, which includes among other improvements the latest version of V-USB. As it so happens, V-USB includes start-of-frame packet detection out of the box, which made it much easier to implement his activity detection code.

With the new firmware flashed to the relay board’s chip, [Michał] put it in an enclosure and wired up the outlets. But there was still one missing piece of the puzzle. It seems that Linux won’t actually send out the start-of-frame packets unless its actively communicating with a USB device, as part of the so-called “selective suspend” power saving feature. Luckily there is support for disabling this feature for specific devices based on their Vendor/Product ID pair, so after a little udev fiddling, everything was working as expected.

We love custom firmware projects here at Hackaday. Not only do they keep proprietary software out of our devices, but they often unlock new and expanded capabilities which otherwise would be hidden behind artificial paywalls.

Game Boy Macro Build Retains DS Compatibility

Building a so-called “Game Boy Macro” is a great way to salvage a Nintendo DS that has a broken hinge or top screen, as the system only needs the lower display to play Game Boy Advance games. Naturally, DS games that were designed to use both screens would no longer be playable. Or at least, that’s what we thought. But as [Facelesstech] shows, it’s actually possible to play DS games on a Game Boy Macro if you do a little extra soldering.

It turns out that there are two test points on the original DS motherboard where you can pick up the signal for the top and bottom screens respectively. With just three wires and a simple switch, you can select which signal gets fed into the bottom screen in real-time with no image degradation. Now, this won’t do you any good on games that make constant use of both the top and bottom DS displays, but for many titles, the bottom screen was used for little more than a map or inventory display that you only need to glance at occasionally.

Installed screen switch. Note USB-C upgrade module.

With the ability to switch between them at will, a large number of DS games are perfectly playable with just one screen. Interestingly, the touch panel still works the same regardless of which video feed is being pipped in; so if you memorize which areas need to be touched to perform different actions, you don’t even need to flip the images. In the video below, [Facelesstech] demonstrates the concept with New Super Mario Bros, which would otherwise be unplayable as the action usually is shown on the top screen.

This hack is only possible because the two displays on the DS are identical beyond the touch overlay, which as we learned during a previous deep-dive into the technology behind this revolutionary handheld, was a trick Nintendo used to squeeze as much performance as they could out of its relatively meager 3D hardware. Unfortunately, it seems like the modification is much harder to pull off on the DS Lite, so it wouldn’t be compatible with the slick Game & Watch styled Game Boy Macro we covered recently. Continue reading “Game Boy Macro Build Retains DS Compatibility”

Raspberry Pi Zero Takes The Wheel In Miniature Fighting Robot

Looking to capitalize on his familiarity with the Raspberry Pi, [Sebastian Zen Tatum] decided to put the diminutive Pi Zero at the heart of his “antweight” fighting robot, $hmoney. While it sounds like there were a few bumps in the road early on, the tuxedoed bot took home awards from the recent Houston Mayhem 2021 competition, proving the year of Linux on the battle bot is truly upon us.

Compared to using traditional hobby-grade RC hardware, [Sebastian] says using the Pi represented a considerable cost savings. With Python and evdev, he was able to take input from a commercial Bluetooth game controller and translate it into commands for the GPIO-connected motor controllers. For younger competitors especially, this more familiar interface can be seen as an advantage over the classic RC transmitter.

A L298N board handles the two N20 gear motors that provide locomotion, while a Tarot TL300G ESC is responsible for spinning up the brushless motor attached to the “bow tie” spinner in the front. Add in a Turnigy 500mAh 3S battery pack, and you’ve got a compact and straightforward electronics package to nestle into the robot’s 3D printed chassis.

In a Reddit thread about $hmoney, [Sebastian] goes over some of the lessons his team has learned from competing with their one pound Linux bot. An overly ambitious armor design cost them big at an event in Oklahoma, but a tweaked chassis ended up making them much more competitive.

There was also a disappointing loss that the team believes was due to somebody in the audience attempting to pair their phone with the bot’s Pi Zero during the heat of battle, knocking out controls and leaving them dead in the water. Hopefully some improved software can patch that vulnerability before their next bout, especially since everyone that reads Hackaday now knows about it…

While battles between these small-scale bots might not have the same fire and fury of the televised matches, they’re an excellent way to get the next generation of hackers and engineers excited about building their own hardware. We wish [Sebastian] and $hmoney the best of luck, and look forward to hearing more of their war stories in the future.

Turning The Virtual Boy Into A Handheld Console

The Virtual Boy, Nintendo’s most infamous failure, was plagued by several issues. The most glaring problem was the red monochrome stereoscopic display technology which gave many users a headache after even a short time playing, but it’s sky-high price and extremely limited library of games kept many prospective buyers at bay as well. There was also the issue of portability: unlike the Game Boy it was named after, the Virtual Boy barely qualified as a portable system due to the fact it needed to be set up on a table to use.

But now, thanks to the tireless efforts of [Shank], at least a few of those issues have been resolved. He’s built the world’s first truly portable Virtual Boy, which swaps the system’s troubled 3D display for a modern IPS LCD panel. The custom handheld, designed to merge the Virtual Boy’s unique aesthetic with the iconic styling of the Game Boy Advance, looks like it came from some alternate timeline where Nintendo decided to produce a cheaper and less cumbersome version of the system rather than abandoning it.

While the work [Shank] has put into the project is unquestionably impressive, it should be said that it took the efforts of several talented hackers to create the handheld Virtual Boy. The key component that made the modification possible in the first place is the VirtualTap by [Furrtek], which not only provides the VGA output that’s driving the LCD panel, but fools the system’s motherboard into believing the servo-actuated stereoscopic display is still connected and active.

It’s also using the open source power management board that [GMan] originally developed for his own portable N64, [Bassline] chipped in to cast the custom buttons and D-pad in translucent resin, and [Mitch 3D] put an untold number of hours into printing and reprinting the system’s multicolored enclosure until it came out just right.

All the little details of the final system, which [Shank] calls the Real Boy, put this project into a league of its own. Special combinations of button presses allows the user to change the color of the display, should you get sick of the infamous red-tint. The buttons also have RGB LEDs behind them that correspond with the color scheme of the display itself, for that extra bit of gamer cred. He even made sure to include the system’s original link port, despite the fact that no officially released game ever made use of it.

Our first run in with [Shank] was when he demoed a portable Wii built into a mint tin. It made for a pretty pitiful gaming experience, but the project demonstrated his dedication to seeing a project through to the end. Watching his skills improve over the last few years has been inspiring, and we can’t wait to see what he comes up with next.

Continue reading “Turning The Virtual Boy Into A Handheld Console”

Restoring A Vintage Tube Tester To Its Former Glory

It can be difficult for modern eyes to make much sense of electronics from the 1960s or earlier. Between the point-to-point soldering, oddball components, and the familiar looking passives blown up to comical proportions like rejected props from “Honey, I Shrunk the Kids”, even experienced hardware hackers may find themselves struggling to understand what a circuit is doing. But that didn’t stop [Cat0Charmer] from taking the time to lovingly restore this Hickok Cardmatic KS-15874-L2 tube tester.

The good news was that the machine had nearly all of its original parts, down to the Hickok branded tubes in the power supply. Unfortunately it looks like a few heavy handed repairs were attempted over the years, with a nest of new wires and components intermixed with what [Cat0Charmer] actually wanted to keep. The before and after shots of individual sections of the machine are particularly enlightening, though again, don’t feel to bad if you still can’t make heads or tails of the cleaned up version.

Hiding new capacitors inside of the old ones.

As you’d expect for a machine of this age, many of the original components were way out of spec. Naturally the capacitors were shot, but even the carbon composition resistors were worthless after all these years; with some measuring 60% away from their original tolerances.

We particularly liked how [Cat0Charmer] hollowed out the old capacitors and installed the new modern ones inside of them, preserving the tester’s vintage look. This trick wasn’t always feasible, but where it was applied, it definitely looks better than seeing a modern capacitor adrift in a sea of 60’s hardware.

After undoing ham-fisted repairs, replacing the dud components, and installing some new old stock tubes, the tester sprung to life with renewed vigor. The previously inoperable internal neon lamps, used by the tester’s voltage regulation system, shone brightly thanks to all the ancillary repairs and changes that went on around them. With a DIY calibration cell built from the schematics in an old Navy manual, [Cat0Charmer] got the tester dialed in and ready for the next phase of its long and storied career.

We love seeing old hardware get restored. It not only keeps useful equipment out of the scrap heap, but because blending new and old technology invariably leads to the kind of innovative problem solving this community is built on.