These days, most of us take the instant availability of a high-speed link to the Internet for granted. But despite all of the latest technology, things still occasionally go pear-shaped — meaning that blistering fiber optic connection you’ve got to the world’s collected knowledge (not to mention, memes) can still go down when you need it the most.

After suffering some connectivity issues, [Arnov Sharma] decided to put together a little box that could alert everyone in visual range to the status of the local router. It won’t fix the problem, of course, but there’s a certain value to getting timely status updates. Using a 3D printed enclosure and a couple of custom PCBs, the build is fairly comprehensive, and could certainly be pressed into more advanced usage if given the appropriate firmware. If you’ve been thinking of a Internet-connected status indicator, this is certainly a project worth copying studying closely.

The aptly named “Wi-Fi Status Box” uses two PCBs: one to hold the Seeed Studio XIAO ESP32C3 microcontroller and four WS2812B addressable LEDs, and another that plays host to the IP5306 power management IC.

That latter board in particular is something you may want to file away for a future project, as it not only handles charging lithium-ion batteries such as common 18650 cells, but it also features an LED “fuel gauge” and the ability to boost the output power to 5 VDC with relatively few external components.

As for the firmware on this one, it’s simplicity itself. The goal is to see if the router has gone down, so all the code does is check every ten seconds to see if the ESP32 is still able to connect to the given wireless network. If the connection is good the LEDs are green, but if the link fails, they flip over to red. Combined with a printed front panel that uses transparent filament to soften the glow of the LEDs, and you’ve got an attractive way of knowing when it’s time to panic.

Too obvious for you? Perhaps you’d prefer this version that uses an analog multimeter to display when the net drops out.

Besides Pokémon, there might have been no greater media franchise for a child of the 90s than the Transformers, mysterious robots fighting an intergalactic war but which can inexplicably change into various Earth-based object, like trucks and airplanes. It led to a number of toys which can also change shapes from fighting robots into various ordinary objects as well. And, perhaps in a way of life imitating art, plenty of real-life robots have features one might think were inspired by this franchise like this transforming quadruped robot.

Called the CYOBot, the robot has four articulating arms with a wheel at the end of each. The arms can be placed in a wide array of positions for different operating characteristics, allowing the robot to move in an incredibly diverse way. It’s based on a previous version called the CYOCrawler, using similar articulating arms but with no wheels. The build centers around an ESP32-S3 microcontroller, giving it plenty of compute power for things like machine learning, as well as wireless capabilities for control or access to more computing power.

Both robots are open source and modular as well, allowing a range of people to use and add on to the platform. Another perk here is that most parts are common or 3d printed, making it a fairly low barrier to entry for a platform with so many different configurations and options for expansion and development. If you prefer robots without wheels, though, we’d always recommend looking at Strandbeests for inspiration.

When the project description starts with the sentence “I use an RC remote and receiver, an esp32, high-current motor drivers, servos, an FPV camera, and a little propane”, you know that this is one which deserves a second look. And so [gearscodeandfire]’s Halloween project caught our eye. It’s a pink Power Wheels jeep driven by a skeletal rider, and the best part is that the whole thing is remote controlled down to a pan-and-tilt skull, a first-person video feed, and even real flames.

At its heart is an ESP32 with a set of motor controllers and relays to do the heavy lifting. The controller is a standard radio remote controller, and the first-person view is an analogue feed as you’d find on a drone. The skeleton is given a child-like appearance by discarding the original adult-proportioned plastic skull and replacing it with a much larger item. The thought that plastic Halloween skulls are available in a range of standard sizes and can be considered as a part in their own right is something we find amusing. The propane burner is supplied from a small cylinder via a solenoid valve, and ignited with the spark from a high-voltage transformer.

The result, we think, wins Halloween hands down. Twelve-foot skeletons are SO 2023!

The video is below the break.

https://hackaday.io/project/199110-ghost-toddler-esp32-fpv-pan-tilt-power-wheels

Let’s say you’ve got a fun little organization that does things together under a collective branding or banner. Maybe you want to celebrate that fact with some visually appealing signage? Well, that’s pretty much how [Jack] of the Purdue Hackers felt, so he and the gang put together a sizable logo sign to advertise their makerspace.

[Jack] explains that The Sign, as it is known, embodies the spirit of the Purdue Hackers. Basically, it’s about making something cool and sharing it with the world. He then outlines how they came to develop a “shining monument” to their organization with the use of LEDs and 3D printed components. The blog post explains how the group began with small prototypes, before stepping up to build a larger version for display in their makerspace window. It also chronicles the twists and turns of the project, including budget snarls and PCB errors that threatened to derail everything.

Ultimately, though, the Purdue Hackers prevailed, and The Sign has been shining bright ever since. Files are on GitHub for the curious, because it’s all open source! Meanwhile, if you’ve been cooking up your own neat signage projects, don’t hesitate to drop us a line!

A decade ago, [Jouke Waleson] bought a Dutch ‘model 1950’ PTT (The Dutch Postal Service) rotary-dial telephone of presumably 1950s vintage manufactured by a company called Standard Electric, and decided it would be neat to hack it to function as a Bluetooth hands-free device. Looking at the reverse, however, it is stamped “10.65” on the bottom, so maybe it was made as recently as 1965, but whatever, it’s still pretty old-tech now.

The plan was to utilise ESP32 hardware with the Espressif HFP stack to do all the Bluetooth heavy lifting. [Jouke] did find out the hard way that this is not a commonly-trodden path in hackerland, and working examples and documentation were sparse, but the fine folks from Espressif were on hand via GitHub to give him the help he needed. After ripping into the unit, it was surprisingly stuffed inside there. Obviously, all the switching, even the indication, was purely electromechanical, which should be no surprise. [Jouke] identified all the necessary major components, adding wires and interfacing components as required, but was a bit stumped at the function of one funky-looking component that we reckon must be a multi-tap audio transformer, oddly finished in baby pink! After renovating some interesting cross-shaped mechanical indicators and wiring up some driving transistors, it was time to get on to the audio interface.

Initially, [Joike] planned to use an INMP441 I²S digital microphone module, but this was incompatible with the standard ESP32 HFP client (used for Bluetooth hands-free support), so [Jouke] pivoted and used a WM8782-based ADC board for audio input. This also allowed the existing microphone to be used simply by biasing

it to 5 Volts and hooking it straight up to the ADC board via a coupling capacitor. This was a happy outcome, as the modern digital microphone would have sounded very different to the original equipment! On the speaker side, a PCM5102 I²S audio DAC module was pressed into service. The ringer/buzzer needed seven volts, so adding a boost converter board was also necessary. It’s a minor annoyance for powering a single device, but this is a one-off hack, so it’s no big deal. Finally, the backplate was modified to add a USB-C module and a power switch so it could be power-cycled, giving access to the ESP32 boot loader and enabling firmware updates without opening the case.

The outfit’s brains are courtesy of a LilyGo T-Koala board, a basic breakout board based around the older ESP32-WROVER module. This was necessary as the newer ESP32 chips drop Bluetooth classic support and, with it, support for handling the Bluetooth hands-free protocol. We were particularly ticked by the project tagline, “Bakelite to the future”, and that lifting the phone when not answering an incoming call connects you to Google Assistant or Siri! Nice work! For a look over the source code for the project, check out the GitHub page.

This is not the first modernisation of a classic telephone, and we hope it won’t be the last. Here’s an older GSM-based hack. If all this talk of rotary phones and tethered handsets confuses you, here’s our guide to this older telephone system. Telephones weren’t the only old-school home appliances constructed from Bakelite—far from it. It was also used to make many radios.

If you’re looking for a hackerspace while on your travels, there is more than one website which shows them on a map, and even tells you whether or not they are open. This last feature is powered by SpaceAPI, a standard way for hackerspaces to publish information about themselves, including whether or not they are closed.

Given such a trove of data then it’s hardly surprising that [S3lph] would use it to create a gigantic map of central Europe with lights in the appropriate places (German language, Google Translate link) to show the spaces and their status.

The lights are a set of addressable LEDs and the brain is an ESP32, making this an accessible project for most hackers with the time to assemble it. Unsurprisingly then it’s not the first such map we’ve seen, though it’s considerably more ambitious than the last one. Meanwhile if your hackerspace doesn’t have SpaceAPI yet or you’re simply curious about the whole thing, we took a look at it back in 2021.

Thanks [Dave] for the tip.

In the past, building construction methods generally didn’t worry much about air quality. There were enough gaps around windows, doors, siding, and flooring that a house could naturally “breathe” and do a decent enough job of making sure the occupants didn’t suffocate. Modern buildings, on the other hand, are extremely concerned with efficiency and go to great lengths to ensure that no air leaks in or out. This can be a problem for occupants though and generally requires some sort of mechanical ventilation, but to be on the safe side and keep an eye on it a CO2 sensor like this unique Pac-Man-inspired monitor can be helpful.

Although there are some ways to approximate indoor air quality with inexpensive sensors, [Tobias] decided on a dedicated CO2 sensor for accuracy and effectiveness, despite its relatively large cost of around $30. An ESP32 handles the data from the sensor and then outputs the results to an array of LEDs hidden inside a ghost modeled after the ones from the classic arcade game Pac-Man. There are 17 WS2812B LEDs in total installed on a custom PCB, with everything held together in the custom 3D printed ghost-shaped case. The LEDs change from green to red as the air quality gets worse, although a few preserve the ghost’s white eyes even as the colors change.

For anyone looking to recreate this project and keep an eye on their own air quality, [Tobias] has made everything from the code, the PCB, and the 3D printer files open source, and has used accessible hardware in the build as well. Although the CO2 sensors can indeed be pricey, there are a few less expensive ways of keeping an eye on indoor air quality. Some of these methods attempt to approximate CO2 levels indirectly, but current consensus is that there’s no real substitute for taking this measurement directly if that’s the metric targeted for your own air quality.

As things get smaller, we can fit more processing power into devices like robots to allow them to do more things or interact with their environment in new ways. If not, we can at least build them for less cost. But the design process can get exponentially more complicated when miniaturizing things. [Carl] wanted to build the smallest 9-axis robotic microcontroller with as many features as possible, and went through a number of design iterations to finally get to this extremely small robotics platform.

Although there are smaller wireless-enabled microcontrollers, [Carl] based this project around the popular ESP32 platform to allow it to be usable by a wider range of people. With that module taking up most of the top side of the PCB, he turned to the bottom to add the rest of the components for the platform. The first thing to add was a power management circuit, and after one iteration he settled on a circuit which can provide the board power from a battery or a USB cable, while also managing the battery’s charge. As for sensors, it has a light sensor and an optional 9-axis motion sensor, allowing for gesture sensing, proximity detection, and motion tracking.

Of course there were some compromises in this design to minimize the footprint, like placing the antenna near the USB-C charger and sacrificing some processing power compared to other development boards like the STM-32. But for the size and cost of components it’s hard to get so many features in such a small package. [Carl] is using it to build some pretty tiny robots so it suits his needs perfectly. In fact, it’s hard to find anything smaller that isn’t a bristlebot.