A fridge magnet with a display showing recycling reminders

Hackaday Prize 2022: BinPal Is A Convenient Recycling Reminder

June 11, 2022 by Robin Kearey 14 Comments

While curbside pickup of recyclables is convenient, it does require you to keep track of which type of waste is picked up when: miss the biweekly paper pickup and you’ll soon find yourself stockpiling four weeks’ worth of boxes and newspapers. When [Dominic Buchstaller]’s stack of cardboard began to reach his ceiling, he decided to take action by building himself BinPal: a fridge magnet that helps you remember when to take out which bin.

At heart of the simple but effective BinPal is an ESP32 board that connects to Google Apps Script and retrieves the pickup schedule from Google Calendar. If one of four categories of waste is due for pickup, its icon is highlighted on an LCD screen. The user can press a touch-sensitive button to confirm the bin has been brought out for pickup; if that hasn’t been done by 8 pm, the display’s backlight starts flashing as an additional reminder.

The outer shell of the device is made from laser-cut plywood, with a few strong magnets glued inside to ensure the BinPal stays firmly attached to the fridge. In the true spirit of recycling, [Dominic] used only components that he had in his parts bin to make the BinPal. However, these parts are all easily available online, and with the full schematics and code available on the project’s Hackaday.io page it should be easy to adapt the design to different hardware platforms as well.

[Dominic]’s design was inspired by a flashing LED chore reminder we featured a few years ago. You can also make household task reminders by reusing a Kindle for its ePaper display.

Odd Inputs And Peculiar Peripherals: A MacroPad With A Handy Layout Screen

June 11, 2022 by Jenny List No comments

The idea of a macro keypad is a great one, a set of keys programmable with frequent but complex tasks. But once programmed, how can the user keep track of which key does what? To save the world from grubby, hand-written sticky labels, here’s [Andreas Känner] with the Badger 2040 keypad — a macro pad with a display to show keymap info that’s fully programmable using CircuitPython.

At its heart is a Pimoroni Badger 2040 e-ink screen and RP2040 board which sits in a 3D-printed enclosure which in turn magnetically attaches to a 3D-printed keyboard enclosure. Inside is an I/O expander board, which is hand-wired to the switches. The firmware allows for easy configuration and even extension of the keypad itself, and presents itself to the host computer through USB. It’s even possible to have multiple different layouts on the same device.

Full details can be found in a comprehensive write-up on his website, and all the files are in a GitHub repository. If this doesn’t satisfy your need for customisable input goodness, then it’s not the first macro keypad we’ve shown you.

The Tools That Lovingly Tore Apart A Vintage Computer Game

June 11, 2022 by Donald Papp 9 Comments

The structure of computer game assets can be a bit of a mystery, even more so the older a game is, and some amount of reverse-engineering can be expected when pulling apart a game like 1995’s Night Light.

[voussoir] had fond memories of this game by GTE Entertainment, which had an interesting “flashlight” mechanic to serve the exploration theme. Spooky shapes in dark rooms would be revealed to be quite ordinary (and therefore not scary at all) once illuminated with a flashlight, which was directed by the mouse.

Extracting game assets was partly straightforward, thanks to many of them being laid out in a handy folder structure, with .bmp files for each level in a modest resolution. But there were also some unusual .mov files that were less than a second long, and those took a little more work to figure out.

It turns out that these unusual movie files were 80 frames in length, and each frame was a tile of a larger image. [voussoir] used ffmpeg to extract each frame, then wrote a Python script to stitch the tiles together. Behold! The results are high-resolution versions of each level’s artwork. Stitching the first 16 frames into a 4×4 grid yields a 1024×768 image, and the remaining 64 frames can be put into a 8×8 grid for a fantastic 2048×1376 version. The last piece was extracting audio, but sadly the ISO [voussoir] was using seems to have had errors, and not all the audio survived.

With intact assets in hand, [voussoir] was able to re-create the core of the game, which can be seen about halfway down into the writeup. Audio clues play simply while the flashlight effect is re-created in the browser with the game’s original level artwork, and it’s enough to ring those nostalgia bells. It’s a pretty successful project, even though not all of the assets have been tracked down, and not all of the audio was able to be extracted due to corruption. If you have any insights on that front, don’t keep them to yourself! Send [voussoir] an email, or chime in here in the comments.

Reverse engineering has a strong history when it comes to games, and has manifested itself in sometimes unusual ways, like the time Atari cracked the NES. Had the subsequent legal challenge gone differently, the game landscape might have looked very different today.

Inside An EBay Marking Laser

June 11, 2022 by Dan Maloney 13 Comments

When it comes to trolling eBay for cool stuff, some people have all the luck. Whereas all we ever seem to come across is counterfeit chips and obviously broken gear listed as, “good condition, powers on”, [Les Wright] actually managed to get more than he bargained for with one of his recent eBay purchases.

In his video teardown and tour of an industrial marking laser, [Les] suggests that he was really just in it for the optics — which is not a surprise, given his interest in optics in general and lasers in particular. The 20-W CO₂ laser once etched barcodes and the like into products on assembly lines, but with a 2009 date code of its own, it was a safe bet that it was pitched due to a burned-out laser tube. But there were still high-quality IR optics and a precision X-Y galvanometer assembly to be harvested, so [Les] pressed on.

The laser itself ended up being built around a Synrad RF-stimulated CO₂ tube. By a happy accident, [Les] found that the laser actually still works, at least most of the time. There appears to be an intermittent problem with the RF driver, but the laser works long enough to release the magic smoke from anything combustible that gets in its way. The galvos work too — [Les] was able to drive them with a Teensy and a couple of open-source libraries.

Galvos, lenses worth more than $800, and a working laser tube — not a bad haul. We’ll be following along to see what [Les] makes of this booty. Continue reading “Inside An EBay Marking Laser” →

Bug Zapper Counts And Serenades Its Victims

June 11, 2022 by Sven Gregori 10 Comments

Not many creatures are as universally despised as mosquitoes, whether it’s the harmless kind that, at worst, makes you miss winter, or the more serious ones that can be a real threat to your health. A satisfying way to deal with them is to send them off with a bang using one of those racket-shaped high voltage metal mesh bug zappers. [lmu34] saw big potential for some additional gamification here, and decided to equip his zapper with a kill counter and matching sound effects.

The initial thought was that there has to be a way to detect when a mosquito hits the mesh, and use that to trigger further events — in [lmu34]’s case play a sound file and increment a counter. After taking the zapper apart and doing a bit of research, he put theory into practice using a Digispark Pro board containing an ATtiny167, the DFPlayer module for playing a set of WAV files, and an ambitious four digit 7-segment display to keep track of the “score”. A new 3d-printed cover provided enough space to house all the components, including a charging circuit as he swapped the original two AAA batteries with a rechargeable one, which gave a bit more power for the display.

Of course, with these operation voltages, it would be difficult to detect activity on the high voltage side more than once, so [lmu34] went with current sensing instead. He distinguishes between two different levels here and maps them as normal kill and monster kill for the big zaps respectively, playing different sounds for each. Have a look at the video after the break for some quick demonstration.

All in all, this is a delightfully absurd modification that almost screams for an ESP32 to enable multiplayer mode as next iteration. But if chasing mosquitoes with low-tech gadgets isn’t for you, there’s always lasers and good old torture, although those can’t be repurposed to do some hardware fault injections during the winter months then.

Continue reading “Bug Zapper Counts And Serenades Its Victims” →

Here’s What It Takes To Fill A Piano With Water

June 10, 2022 by Lewin Day 25 Comments

Filling a piano with water probably sounds frivolous and asinine to many. However, it also sparks a certain curiosity as to what it would be like. Thankfully, [Mattias] put in the hours of work to find out so we don’t have to!

A first attempt with an upright piano failed quickly. After just four minutes submerged in water, the wooden hammers would seize up as they swelled with moisture.

A grand piano was sourced for a second attempt. The strings were first detensioned to make things easier to work with, and the internal frame pried out from the surrounding piano body. To stop the water pouring out past the keys and strings, a simple solution was implemented: tilting the piano up so the water remained in the body below. A judicious application of various sealing agents was then used to seal the frame. Amazingly, the best information on sealing a piano came from enthusiasts building aquariums out of plywood boxes. Go figure.

The water has a muting effect on the piano’s sound as you might expect. The sound is particularly compelling when heard via underwater mics placed in the water-filled cavity. It almost sounds like a plucked instrument, and gives everything a strangely maritime feel. The sound waves can be seen on the surface of the water, too.

The experiment came to a tragic end when the piano was overfilled, dumping water over the keys and hammers. This caused every key to jam, killing the piano for good.

It’s a fun build, and a very silly one, if you can stand to watch a piano treated in this way. [Mattias] has form in the area of oddball instrument hacks, too, as we’ve previously featured his helium guitar. Video after the break.

Continue reading “Here’s What It Takes To Fill A Piano With Water” →

Simple Snap Action Mechanism Is 100% 3D Printed

June 10, 2022 by Lewin Day 7 Comments

Plastics are wonderous materials, much loved for their ability to elastically deform and spring back to their original shape. They’re a category of materials perfect for creating things like living hinges and similar mechanisms, and this 3D printed snap action device shows that off admirably.

The device consists of an outer housing, into which two printed springs are inserted. These leaf springs are curved and protrude towards the center of the housing. A slide is then inserted into the housing with a cam in its middle. The cam allows the slide to push past the springs when actuated, while also holding it in place at rest.

As demonstrated the mechanism reliably snaps back and forth between its two positions in a satisfying manner. It’s shown with one side of the housing removed so we get a good idea of how it works. It’s 100% 3D printed, as well. Anyone looking to replicate the design should note the importance of printing orientation, particularly in the case of the spring pieces, which won’t work if layered up in the wrong way.

Overall, it’s a neat design that could prove useful for those eager to build printed switches or other mechanical devices. It’s also simply a great way to learn about 3D printed springs and working with deformable plastic structures. Video after the break.

Continue reading “Simple Snap Action Mechanism Is 100% 3D Printed” →