Keeping track of your 3D-printer filament use can be both eye-opening and depressing. Knowing exactly how much material goes into a project can help you make build-versus-buy decisions, but it can also prove gut-wrenching when you see how much you just spent on that failed print. Stock filament counters aren’t always very accurate, but you can roll your own filament counter from an old mouse.

[Bin Sun]’s build is based around an old ball-type PS/2 mouse, the kind with the nice optical encoders. Mice of this vintage are getting harder to come by these days, but chances are you’ve got one lying around in a junk bin or can scrounge one up from a thrift store. Stripped down to its guts and held in place by a 3D-printed bracket, the roller that used to sense ball rotation bears on the filament on its way to the extruder. An Arduino keeps track of the pulses and totalizes the amount of filament used; the counter handily subtracts from the totals when the filament is retracted.

Simple, useful, and cheap — the very definition of a hack. And even if you don’t have a 3D-printer to keep track of, harvesting encoders from old mice is a nice trick to file away for a rainy day. Or you might prefer to just build your own encoders for your next project.

If you’ve been looking for a robotic assistant with the functionality of an Amazon Echo and the cuteness of a Disney character, you’re in luck. That’s because Abhishek Singh has created Peeqo, an open-source DIY device that responds to human speech through GIFs.

Peeqo has a Raspberry Pi 3 for his brain along with a pair of Arduino Mini boards for controlling movement and LED notifications. The 3D-printed bot is equipped with a half-dozen servos, four custom microphones, a NeoPixel ring on top of his head, a camera at his chest, a USB speaker, and an LCD display.

As for voice recognition, Peeqo uses the Google Speech API for detecting the wake word ‘Peeqo’ and API.AI for responding to the query. The desktop companion can also serve as a full-fledged entertainment system that plays your favorite Spotify tunes. Ask for a song and he’ll sway to the beat.

But that’s not all. Singh even developed a Chrome extension that uses Peeqo to boost his productivity and motivate him to avoid social media while working. Once he tells it to block a certain site, the robot lets his displeasure be known in the form of a GIF.

Intrigued? You can see how Singh brought Peeqo to life on Imgur.

After considering building a square word clock, Maker Roald Hendriks and his sister came up with something a bit more unique!

Clocks, being decorative, useful and easily hackable, have been targets for creative types, likely from when they were first invented. You’d think maybe all ideas for new clocks have been exhausted. Fortunately, human ingenuity never seems to run dry, and this latest device tells time using Arduino Uno-controlled LEDs.

Outer numbers on the modified IKEA PUGG wall clock illuminate to indicate the hour, while words on the inside represent the minutes. These minutes are literally spelled out in Dutch phrases reveal the particular time, but if you don’t speak the language, the position of the LEDs should give you some clue as to what is going on.

You can read more about the project on its website, and watch a demo below!

[LDX] first noticed the odd sounds coming out of his ceiling fan, regularly, on the hour and half-hour. Then he noticed that the lights were flickering as well. Figuring something was up, he built a logging power-line monitor to see if he could decode the shadowy signals and figure out what cryptic messages were being transmitted over the power lines. Naturally, he suspected the Illuminati were behind it.

Even if you’re not prone to flights of fancy, you might want to keep track of your power line because it can serve as an accurate long-run timebase for projects, or because it can tell you something about the overall health of the grid.

[LDX]’s circuit is as simple as can be. A 10 V AC transformer reduces the mains power down to something reasonable. A resistive divider chops this down further to the range that an Arduino can handle, and then another voltage divider biases the signal to the Arduino’s ADC midpoint. The plus-minus 10 V signal thus swings between 0 and 5 V, just.

SPOILERS! After confirming that there was a higher-frequency wiggle superimposed on top of the power-line frequency, he contacted the folks at his power company in Denver. The system is called Decabit and it’s used to control street lights, hot water boilers, and other public infrastructure that might want to be coordinated to run when power is cheap or when it gets dark. The PDF that he links to explains it all, so you can take your tinfoil hat right back off.
But we still think it’s a fun project to look into the power lines. Who knows what other people will find? CON-spiracy!

Love eating lunch, but hate making it? Good news, an automated machine may soon be able to take care of the task for you. Meet Sandwich-o-Matic, a voice-controlled, robotic sandwich-building station.

The project–which was created during a thirty-six hour hackathon by the team of Clive Chan, Colin Daly, Alex Foley and Wilson Wu–is based on an Arduino and a Photon. A rotating dispenser is driven by a series of servos, while a DC motor is responsible for a toaster-lifting mechanism. The backend is running Node.js, hosted on AWS, and the Google Cloud Platform handles the voice-to-text features.

The Sandwich-o-Matic accepts both voice and NFC requests. Simply place your order by saying the ingredients, or tapping their respective images on an accompanying menu. The device will then begin crafting your lunch from scratch.

The Makers hope to even develop a future version, which will include more topping and condiment options as well as a more streamlined voice-to-sandwich process. You can read more about the project on Devpost and its GitHub page.

If you simply want to have a drink now and then, building your own automated distillery probably isn’t the easiest way to obtain alcohol. As shown in this Instructables post, however, it can be done. On the other hand, if you create your own “NanoStillery,” you’ll have to contend with possible legal and safety issues while running the process… and of course, the risks of actually using the product.

Though the writeup appears quite good, with three control panels, custom mechanical components and a nicely-welded frame, it’s likely not a good project to attempt without a bit of engineering experience!

There are three panel boxes in the NanoStillery™, the main panel is driven by an Arduino Mega and the secondary one houses an Adafruit Feather GPRS board for transmitting data to the interweb. The third box has a large 12V power supply and a bank of relays in it.

The main control panel receives information from the various sensors in the system—temperatures, pressure and alcohol vapor levels and controls various valves, pump and the boiler heater via the relays. It then communicates with the Adafruit Feather via the I2C bus which then sends the data to a database where it is accessed from this webpage.

The GPRS module could very well have been bolted into the main control panel, but, for one, I had run out of room and secondly, I wanted the module to be removable so that it could be used for other projects in the future. Getting the two ‘machines’ to communicate with each other effectively was quite challenging. It was OK if the numbers were just simple small integers, but as soon as more complex ‘floats’ were involved, some serious number crunching code had to be developed.

Want to learn more? You can find all the necessary information on NanoStillery, including its code, over on Instructables.

The Rex800 looks like a dinosaur Terminator, a terrifying proposition, and perhaps a great merchandising opportunity!

YouTuber “RobitFactory” is in the process of creating a 1/10 replica of the “Sue” dinosaur skeleton, now featured at the Field Museum of Natural History in Chicago. What he has at the moment is a rough frame made out of tubing, as well as a metallic gray head with glowing red eyes.

The video takes us through the build process, along with some of RobitFactory’s future plans which include voice-activation. It’s an ambitious project, and in preparation for upgrades, he’s switched out the Arduino Uno used originally for a Mega board, and installed a Molex connector on the head so it can be easily disconnected. It will be exciting to see where this build goes!

Intrigued? Be sure to check out the RobitFactory’s YouTube page.

If you’ve been in a university class of a certain size, with a professor who wants to get live feedback from the students, you’ve probably been forced to buy a Turning Point “clicker”. Aside from the ridiculousness of making students pay for their professor’s instructional aides (do the make you pay extra for the chalk too?!?!) these clickers are a gauntlet thrown down to any right-minded hacker because they supposedly contain secrets.

[Nick] had one of these gadgets, and hopped right up on the shoulders of giants to turn it into a remote control that interfaces with his computer and drives a synthesizer, so he can work through the chord changes by clicking. His two references, to [Travis Goodspeed]’s nRF promiscuity hack and to [Taylor Killian]’s Arduino library for the clickers are a testament to why we need both reverse engineers doing the hard work and people who’ll wrap up the hard work in an easy-to-use library.

That’s it, really. [Nick] hooked up an Arduino to an nRF24, sent the decoded output from the clicker to his computer, and wrote a Python routine that would play whatever music he wanted over MIDI to a baseline synthesizer. The whole shooting match is available on GitHub. If you have one of these clickers collecting dust somewhere, pull it out and do something with it.