The year is 2016. Driving home from a day’s work in the engineering office, I am greeted with a sight familiar to any suburban dwelling Australian — hard rubbish. It’s a time when local councils arrange a pickup service for anything large you don’t want anymore — think sofas, old computers, televisions, and the like. It’s a great way to make any residential area temporarily look like a garbage dump, but there are often diamonds in the rough. That day, I found mine: the Ricoh Aficio 2027 photocopier.
It had spent its days in a local primary school, and had survived fairly well. It looked largely intact with no obvious major damage, and still had its plug attached. Now I needed to get it home. This is where the problems began.
Sometimes — despite impracticality, safety, failure, and general good sense — one has an urge to see a project through for the sake of it. When you’re sick of buttering your toast every morning, you might take a leaf out of Rick Sandc– ahem, [William Osman]’s book and build a toast-bot to take care of the task for you.
[Osman] — opting for nail the overkill quotient — is using a reciprocating saw motor to hold the butter while the toast moves underneath the apparatus on a platform controlled by a linear stepper motor. The frame and mounts for Toast-Bot were cut out of wood on his home-built laser cutter — affectionately named Retina Smelter 9000′ — and assembled after some frustration and application of zip-ties. The final result DOES butter toast, but — well — see for yourself.
It’s the year 2260 and you’re being beamed from your starship to the planet below. Being a descendant of present day 3D printers, the transporter prints you out, slowly making one layer before moving on to the next, going from the ground up. The you-that-was hopes nothing spills out before you’re done. But what if you could print every atom in your body at the same time? If those transporters are descendant’s of Daqri’s holographic 3D printing technology then that’s just what will happen.
Daqri’s process is akin to SLA (stereolithography) and SLA/DLP (digital light processing). In SLA, a laser beam is shone onto a pool of resin, hardening the resin at the beam’s point. The laser scans across the resin’s surface, drawing one layer. More resin is added and then the next layer is drawn. In SLA/DLP, the light for an entire layer is projected onto the surface at once. While both methods involve stereolithography, the acronym SLA by itself is commonly used to refer to the laser approach.
Daqri’s process however, uses a holographic chip of their own making to project the light for all the layers at the same time into the material, a light-activated monomer. Their chip is a silicon wafer containing a grid of tunable crystals. Those crystals control the magnitude and phase of light reflected down into the monomer, creating a 3D volume of interference patterns. The brief description of the process says that a laser is used to shine light onto the crystals, so there’s probably still some scanning going on. However, in the video, all of the object being printed appears illuminated at the same time so the scanning is likely very fast, similar to how a laser in a light show seemingly paints what appears to be a 2D shape on the side of a building, even though it’s really just a rapidly moving point. There’s also the possibility that the beam’s point is large enough to encapsulate all of the chip at once. You can see a demonstration of it in the video below.
If you are fascinated by stories you read on sites like Hackaday in which people reverse engineer wireless protocols, you may have been tempted to hook up your RTL-SDR stick and have a go for yourself. Unfortunately then you may have encountered the rather steep learning curve that comes with these activities, and been repelled by a world with far more of the 1337 about it than you possess. You give up after an evening spent in command-line dependency hell, and move on to the next thing that catches your eye.
You could then be interested by [Jopohl]’s Universal Radio Hacker. It’s a handy piece of software for investigating unknown wireless protocols. It supports a range of software defined radios including the dirt-cheap RTL-SDR sticks, quickly demodulates any signals you identify, and provides a whole suite of tools to help you extract the data they contain. And for those of you scarred by dependency hell, installation is simple, at least for this Hackaday scribe. If you own an SDR transceiver, it can even send a reply.
To prove how straightforward the package is, we put an RTL stick into a spare USB port and ran the software. A little investigation of the menus found the spectrum analyser, with which we were able to identify the 433 MHz packets coming periodically from a wireless thermometer. Running the record function allowed us to capture several packets, after which we could use the interpretation and analysis screens to look at the binary stream for each one. All in the first ten minutes after installation, which in our view makes it an easy to use piece of software. It didn’t deliver blinding insight into the content of the packets, that still needs brain power, but at least if we were reverse engineering them we wouldn’t have wasted time fighting the software.
We’ve had so many reverse engineering wireless protocol stories over the years, to pick only a couple seems to miss the bulk of the story. However both this temperature sensor and this weather station show how fiddly it can be without a handy software package to make it easy.
The PCB design itself is great. It’s got a gigantic LED array, cutout for a wrist strap, and an onboard USB plug so you can program it just by sticking it in your computer; it shows up as a USB mass storage device when you plug it in. The files that show up on the “drive” are Micropython code that you can edit, save, and then run directly on the device. You can hardly beat that for convenience.
And there’s a full complement of sensors: not one but two temperature and humidity sensors, including our recent favorite BME280, which also reads barometric pressure. (We suspect that makes it a tri-corder.) There’s a real-time clock, a buzzer, and some buttons. Want to add more sensors? I2C ports are broken out for your convenience.
Besides having Star Trek flair, this board would give the various educational platforms a run for their money: Micro:bit, we’re looking at you. Very cool indeed!
Instructables user [Team_Panic] — inspired by the resurgence of robot battle arena shows — wanted to dive in to his local ‘bot building club. Being that they fight at the UK ant weight scale with a cap of 150 grams, [Team_Panic] built a spunky little Arduino Mini-controlled bot on the cheap.
The Instructable is aimed at beginners, and so is peppered with sound advice. For instance, [Team_Panic] advises building from “the weapon out” as that dictates how the rest of the robot will come together around it. There are also some simple design considerations on wiring and circuit boards considering the robot in question will take a few hits, as well as instructions to bring the robot together. To assist any beginners in the audience, [Team_Panic] has provided his design for a simple, “slightly crude,” wedge-bot, as well as his code. Just don’t forget to change the radio pipe so you aren’t interfering with other bots!
Okay fellow Make-Gyvers, what do you get when you cross a peripheral power cable jumper, a paperclip, springs, and some 3D-printed housings? DIY test lead clips.
Test clips are easily acquired, but where’s the fun in that? [notionSuday] started by removing the lead connectors from the jumper, soldering them to stripped lengths of paperclip, bent tabs off the connectors to act as stoppers, and slid springs over top. Four quick prints for the housings later, the paperclip assembly fit right inside, the tips bent and clipped to work as the makeshift clamp. Once slipped onto the ends of their multimeter probes, they worked like a charm.