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.

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.