Network Booting The Pi 4

November 11, 2019 by Jonathan Bennett 106 Comments

We’ve talked about PXE booting the Raspberry Pi 3B+, and then looked at the Raspberry Pi 4 as a desktop replacement. But there’s more! The Pi 4 sports a very useful new feature, the flashable bootloader. Just recently a beta version of that bootloader was released that supports PXE — booting up over the network — which has become a must-have for those of us who have had consistently bad experiences with root filesystems on SD cards.

What are the downsides, I hear you ask? You might see slower speeds going across the network compared to a high quality SD card, particularly with the Pi 4 and its improved SD card slot. PXE does require an Ethernet cable; WiFi is not enough, so you have that restriction to contend with. And finally, this isn’t a portable option — you are tethered to that network cable while running, and tethered to your network to boot at all.

On the other hand, if you’re doing a permanent or semi-permanent install of a Pi, PXE is absolutely a winner. There are few things worse than dragging a ladder out to access a Pi that’s cooked its SD card, not to mention the possibility that you firewalled yourself out of it. Need to start over with a fresh Raspbian image? Easy, just rebuild it on the PXE server and reboot the Pi remotely.

Convinced PXE is for you? Let’s get started! Continue reading “Network Booting The Pi 4” →

Mechanical Seven-Segment Display Mixes Art With Hacking

November 11, 2019 by Dan Maloney 28 Comments

We’re not sure what to call this one. Is it a circuit sculpture? Sort of, but it moves, so perhaps it’s a kinetic circuit sculpture. Creator [Tomohiro Tsuchita] calls it “something beautiful but totally useless,” which we find a tad harsh. But whatever you call it, we think this mechanical seven-segment display is really, really cool.

Before anyone gets to thinking that this is something like the other mechanical seven-segment displays we’ve seen lately, think again. This one is not addressable; it simply goes through the ten digits in order. So you won’t be building a clock from it, although we suppose the mechanism could be modified to allow that. Then again, looking at that drive train of laser-cut acrylic cams, maybe not. Each segment has its own cam with lobes or valleys for each segment. A cam follower lowers and raises the segments as the cams rotate on a common shaft. A full-rotation servo powers the display under the control of a Micro:bit; the microcontroller is overkill for now but will be used in version two, which will allow the speed to change in response to sensors.

Watching this display change at its stately pace is strangely soothing. We love the look of this, but then again, we’re partial to objets d’art-circuit. After all, we ran a circuit sculpture contest earlier in the year, and just wrapped up a Hack Chat dedicated to the subject.

Continue reading “Mechanical Seven-Segment Display Mixes Art With Hacking” →

LCD Panel Lamp Shade Makes For Eye-Catching Lighting

November 11, 2019 by Jenny List 14 Comments

At first sight, [Kyle]’s Elroy lamp is simply an attractive piece of modern-styled interior furnishing; its clean lines, wood grain, and contemporary patterning being an asset to the room. But when he pulls out his phone, things change. Because this lamp hides a secret: at its heart may be a standard LED bulb, but the shade conceals four LCD screens driven by an Nvidia Jetson. These can be controlled through a web app to display a variety of textures, completing the effect.

This is not however simply a set of laptop screens bolted to a lampshade. The screens started life in laptops sure enough, but have since had their reflective backing removed to create a transparent LCD panel. Then an appropriate diffuser had to be found, which after much experimentation became a composite including more than one textured paper. Finally the whole was enclosed in an attractive wooden lamp frame and became part of the furniture. We like it, both as an aesthetically pleasing lamp and as a genuine departure from the norm.

This isn’t the first eye-catching lampshade we’ve brought you, but it’s certainly raised the bar. You can see it in action in the video below the break.

Continue reading “LCD Panel Lamp Shade Makes For Eye-Catching Lighting” →