Well, noises anyway. [Dmitry Morozov] and [Alexandra Gavrilova] present an interesting electronics-based art installation, which probes a large chunk of crystalline magnetite, using a pair of servo-mounted probes, ‘measuring’ the surface conductivity and generating some sound and visuals.

It appears to have only one degree of freedom per probe, so we’re not so sure all that much of the surface gets probed per run, but however it works it produces some interesting, almost random results. The premise is that the point-to-point surface resistivity is unpredictable due to the chaotically formed crystals all jumbled up, but somehow uses these measured data to generate some waveshapes vaguely reminiscent of the resistivity profile of the sample, the output of which is then fed into a sound synthesis application and pumped out of a speaker. It certainly looks fun.

From a constructional perspective, hardware is based around a LattePanda fed samples by an ADS1115 ADC, which presumably is also responsible for driving the LCD monitor and the sound system. An Arduino is also wedged in there perhaps for servo-driving duty, maybe also as part of the signal chain from the probes, but that is just a guess on our part. The software uses the VVVV (Visual Live-programming suite) and the Pure Data environment.

We haven’t seen magnetite used for this type of application before, we tend to see it as a source of Iron for DIY knifemaking, as a medium to help separate DNA or just to make nanoparticles, for erm, reasons.

This Hackaday prize entry from [saul] is the beginning of a reconfigurable kit of 3D printed parts and servo motors for robotics learning. With just access to a printer, a few cheap-as-chips servo motors, an Arduino, and some nuts and bolts, you could be hacking together robot walkers within a few hours of starting!

Bolt Bots is very simple to understand, with all the mechanics and wiring out there in the breeze, but strictly for indoor use we reckon. If you want to add remote control to your application, then drop in one of the ubiquitous nRF24L01 boards and build yourself a copy of the remote control [saul] handily provides in this other project.

There really isn’t a great deal we can say about this, as it’s essentially a build kit with quite a few configuration options, and you just have to build with it and see what’s possible. We expect the number of parts to proliferate over time giving even more options. So far [saul] demonstrates a few flavors of ‘walkers’, a rudimentary ‘robot arm’, and even a hanging drawbot.

The bolt hardware can be found in this GitHub repo, and the remote control code in this second one.

Servo-based designs are sometimes sneered at due to their dubious accuracy and repeatability, but with a little of effort, this can be vastly improved upon. Also, multi-legged walkers need multiple servos and controllers to drive ’em. Or do they?

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Sometimes, finding new ways to use old hardware requires awesome feats of reverse engineering, software sleight of hand, and a healthy dose of good fortune. Other times, though, it’s just as simple as reading the data sheet and paying attention to details.

Not that we’re knocking [upir]’s accomplishment with these tricked-out 16×2 OLED displays. Far from it, in fact — the smoothly animated bar graph displays alphanumerics look fantastic. What’s cool about this is that he accomplished all this without resorting to custom characters. We’ve seen him use this approach before; this time around, the hack involves carefully shopping for a 16×2 OLED display with the right driver chip — a US2066 chip. You’ll still need a few tricks to get things working, like extra pull-up resistors to get the I2C display talking to an Arduino, plus a little luck that you got a display with the right character ROM.

Once all that is taken care of, getting the display to do what you want is mainly a matter of coding. In the video below, [upir] does a great job of walking through the finer points, and the results look great. The bar graphs in particular look fantastic, with silky-smooth animations.

Who says you can’t teach an old robot new tricks? Nobody, actually. That saying is about dogs. But it applies to robots too, at least judging by the way this late-90s industrial beast was put to use in a way it was never intended: as a giant CNC router.

The machine in question is an ABB IRB6400, a six-axis, floor-mounted industrial machine that had a long career welding at a Eurorail factory in Austria before [Brian Brocken] made its acquaintance. He procured the non-working machine — no word on what he paid for it — and moved the 2-ton paperweight into his shop, itself a non-trivial endeavor. After a good scrubbing, [Brian] tried to get the machine started up. An error prevented the robot controller from booting; luckily, there’s a large community of ABB users, and [Brian] learned that one of the modules in the controller needed replacement.

After fixing that — and swapping out the controller’s long-dead backup batteries, plus replacing the original 1.44 MB floppy drive with a USB drive — he was able to bring the machine back to life. Unfortunately, the limited amount of internal memory made it difficult to use for anything complicated, so [Brian] came up with an application to stream coordinates to the controller over a serial port, allowing for unlimited operation. With that in place, plus a simple spindle mounted to the robot’s wrist with a 3D printed adapter, [Brian] was able to carve foam blocks into complex shapes. The video below shows everything from delivery to first chips — well, dust at least.

This build seems to be a significant escalation from [Brian]’s previous large-format CNC machine. He must have something interesting in mind, so stay tuned for details.

The 16×2 LCD display is a classic in the microcontroller world, and for good reason. Add a couple of wires, download a library, mash out a few lines of code, and your project has a user interface. A utilitarian and somewhat boring UI, though, and one that can be hard to read at a distance. So why not spice it up with these large-type custom fonts?

As [Vaclav Krejci] explains, the trick to getting large fonts on a display that’s normally limited to two rows of 16 characters each lies in the eight custom characters the display allows to be added to its preprogrammed character set. These can store carefully crafted patterns that can then be assembled to make reasonable facsimiles of the ten numerals. Each custom pattern forms one-quarter of the finished numeral, which spans what would normally be a two-by-two character matrix on the display. Yes, there’s a one-pixel wide blank space running horizontally and vertically through each big character, but it’s not that distracting.

Composing the custom patterns, and making sure they’re usable across multiple characters, is the real hack here, and [Vaclav] put a lot of work into that. He started out in Illustrator, but quickly switched to a spreadsheet because it allowed him to easily generate the correct binary numbers to pass to the display for each pattern. It seems to have really let his creative juices flow, too — he came up with 24 different fonts! Out favorite is the one he calls “Tron,” which looks a bit like the magnetic character recognition font on the bottom of bank checks. Everyone remembers checks, right?

Hats off to [Vaclav] for a creative and fun way to spice up the humble 16×2 display. We’d love to see someone pick this up and try a complete alphanumeric character set, although that might be a tall order with only eight custom characters to work with. Then again, if Bad Apple on a 16×2 is possible…

Dash cameras are handy as they provide a video recording of interactions on the road. However, their utility comes from the fact that they are always recording while driving. This always-on means power draw. [Kuzysk] took it upon himself to cut that power draw by a factor of almost 70x.

He found his existing dash cam from MiVue consumed 3.5mA in idle which works out to be a whole amp-hour every 12 days. The custom version takes just 50uA which means it will draw an amp-hour in two years. The brains of the chip are formed by an ATmega328 and an LM2596M, which is a simple step-down regulator. Interestingly, [Kuzysk] purchased clones and original chips and found that the cheaper clones had a lower switching frequency but a much lower power draw. Programming an Arduino bootloader onto the board is fairly straightforward and [Kuzysk] kindly provides his code. It can detect the ACC voltage that’s on when the engine is on and is powered by a permanent 12v connection to the battery.

Overall it’s a straightforward hack that goes through rolling your own Arduino, optimizing for low power, and putting it all together into a polished project. Perhaps for the next version, he can use the ATmega to control a cheaper camera and make it smart.

Thanks to [Microchip makes] and [Abe] for the tip!

[Emily Velasco] has an internet provider that provides sub-par connectivity. Instead of repeatedly refreshing a browser tab to test if the network is up, [Emily] decided to create an internet status monitor by embedding indicator lights in a cat skull…for some reason.

The electronics are straightforward, with the complete parts list consisting of an Arduino Nano 33 IoT device connected to a pair of RGB LEDs and 50 Ohm resistors. The Nano attempts to connect to a known site (in this case, the Google landing page) every two seconds and sets the LEDs to green if it succeeds or red if it fails.

The cat skull is thankfully a replica, 3D printed by one of [Emily]’s Twitter acquaintances, and the whole project was housed in a domed security camera enclosure. [Emily] mounts the LEDs into the skull to create a “brain in a jar” effect.

The source is available on GitHub for those wanting to take a look. We’ve featured internet connectivity status indicators in the form of traffic lights here before, as well as various network status monitors and videoconferencing indicator lights.

When you want a backpack that turns heads and gets people talking, you can get ahead of the conversation with a talking backpack. [Nina] created a rucksack with the legendary babbler itself, the infamous Furby.

Believe it or not, no actual Furbies were sacrificed in the making of this backpack. The build uses an Arduino Nano, two servos, and a DFPlayer Mini for audio. A 3D printed faceplate is used for the iconic eyes and face. The code is fairly simple, waiting for a random delay and then triggering one of four effects. It can play a sound or blink and does its best to move the mouth while the sound is playing thanks to the handy busy line coming off the sound module. A unicorn children’s backpack offered a furry shell to stuff the electronics inside. A custom PCB makes the whole thing just a little neater internally.

Perhaps next [Nina] can integrate voice recognition so that the backpack can answer simple questions like an Alexa-powered Furby we’ve seen before.