Posts with «misc hacks» label

How Many Punches Does it Take?

Do you ever wonder just how many punches you have thrown? The answer is going to be different if you happen to use a punching bag as part of your exercise routine. So is the case with the [DuctTapeMechanic] and while restoring an old speed ball punching bag, he decided to combine his passions for sports and electronics by adding a punch counter.

Perhaps most interesting in this build is the method used to monitor the bag. A capacitance proximity sensor most often used for industrial automation is mounted in the wooden base. He just calls it “an NPN capacitive sensor” without mentioning part number but these are rather easy to find from the usual places. It has no problem sensing each punch — assuming you swing strong enough so that the bag comes near the sensor. Two battery packs, an Arduino, and an optocoupler round out the bill of materials. We were a little disappointed not to see any duct tape in the construction of this project, but since the electronics are outside and exposed to the elements, maybe duct tape will be used to install a roof in a future episode.

The [DuctTapeMechanic] likes to repurpose items which would otherwise be thrown away, which is something to be applauded. The frame of this punching bag was welded from a discarded metal bed frame (a regular occupant of crawl spaces and self storage places), and you might remember he repurposed the electric motor from a discarded clothes dryer last month, changing it into a disk sander.

Arduino Bobbin Winding Machine is Freaky Fast

One of the worst things about sewing is finding out that your bobbin — that’s the smaller spool that works together with the needle and the larger spool to make a complete stitch — ran out of thread several stitches ago. If you’re lucky, the machine has a viewing window on the bobbin so you can easily tell when it’s getting dangerously close to running out, but many machines (ours included) must be taken halfway apart and the bobbin removed before it can be checked.

Having spare bobbins ready to go is definitely the answer. We would venture to guess that most (if not all) machines have a built-in bobbin winder, but using them involves de-threading the machine and setting it up to wind bobbins instead of sew. If you have a whole lot of sewing to do and can afford it, an automatic bobbin winder is a godsend. If you’re [Mr. Innovative], you build one yourself out of acrylic, aluminium, and Arduinos.

Here’s how it works: load up the clever little acrylic slide with up to twelve empty bobbins, then dial in the speed percentage and press the start button. The bobbins load one at a time onto a drill chuck that’s on the output shaft of a beefy 775 DC motor. The motor spins ridiculously fast, loading up the bobbin in a few seconds. Then the bobbin falls down a ramp and into a rack, and the thread is severed by a piece of nichrome wire.

An important part of winding bobbins is making sure the thread stays in place at the start of the wind. We love the way [Mr. Innovative] handled this part of the problem — a little foam doughnut around a bearing holds the thread in place just long enough to get the winding started. The schematic, BOM, and CAD files are available if you’d like to make one of these amazing machines for yourself. In the meantime, check out the demo/build video after the break.

Still not convinced that sewing is cool enough to learn? Our own [Jenny List] may be able to convert you. If that doesn’t get you, you might like to know that some sewing machines are hackable — this old girl has a second life as a computerized embroidery machine. If those don’t do it, consider that sewing machines can give you a second life, too.

Thanks for the tip, [Baldpower]!

A Digital Magic 8-Ball? Signs Point to Yes

[FacelessTech] was recently charmed by one of our prized possessions as a kid — the Magic 8-Ball — and decided to have a go at making a digital version. Though there is no icosahedron or mysterious fluid inside, the end result is still without a doubt quite cool, especially for a project made on a whim with parts on hand.

It’s not just an 8-ball, it also functions as a 6-sided die and a direct decider of yes/no questions. Underneath that Nokia 5110 screen there’s an Arduino Pro Mini and a 3-axis gyro. Almost everything is done through the gyro, including setting the screen contrast when the eight ball is first powered on. As much we as love that aspect, we really like that [FacelessTech] included a GX-12 connector for easy FTDI programming. It’s a tidy, completely open-source build, and there’s even a PCB. What’s not to like? Be sure to check out the video after the break to see it in action.

Believe it or not, this isn’t the smallest Magic 8-Ball build we’ve seen. Have you met the business card version?

[via adafruit]

Reel in the Years with a Cassette Player Synth

Variable-speed playback cassette players were already the cool kids on the block. How else are you going to have any fun with magnetic tape without ripping out the tape head and running it manually over those silky brown strips? Sure, you can change the playback speed on most players as long as you can get to the trim pot. But true variable-speed players make better synths, because it’s so much easier to change the speed. You can make music from anything you can record on tape, including monotony.

[schollz] made a tape synth with not much more than a variable-speed playback cassette player, an Arduino, a DAC, and a couple of wires to hook it all up. Here’s how it works: [schollz] records a long, single note on a tape, then uses that recording to play different notes by altering the playback speed with voltages from a MIDI synth.

To go from synth to synth, [schollz] stood up a server that translates MIDI voltages to serial and sends them to the Arduino. Then the DAC converts them to analog signals for the tape player. All the code is available on the project site, and [schollz] will even show you where to add Vin and and a line in to the tape player. Check out the demo after the break.

There’s more than one way to hack a cassette player. You can also force them to play full-motion, color video.

Via adafruit

Custom Strain Gauges Help Keep Paraglider Aloft

No matter what they’re flying, good pilots have a “feel” for their aircraft. They know instantly when something is wrong, whether by hearing a strange sound or a feeling a telltale vibration. Developing this sixth sense is sometimes critical to the goal of keeping the number of takeoff equal to the number of landings.

The same thing goes for non-traditional aircraft, like paragliders, where the penalty for failure is just as high. Staying out of trouble aloft is the idea behind this paraglider line tension monitor designed by pilot [Andre Bandarra]. Paragliders, along with their powered cousins paramotors, look somewhat like parachutes but are actually best described as an inflatable wing. The wing maintains its shape by being pressurized by air coming through openings in the leading edge. If the pilot doesn’t maintain the correct angle of attack, the wing can depressurize and collapse, with sometimes dire results.

Luckily, most pilots eventually develop a feel for collapse, sensed through changes in the tension of the lines connecting the wing to his or her harness. [Andre]’s “Tensy” — with the obligatory “McTenseface” surname — that’s featured in the video below uses an array of strain gauges to watch to the telltale release of tension in the lines for the leading edge of the wing, sounding an audible alarm. As a bonus, Tensy captures line tension data from across the wing, which can be used to monitor the performance of both the aircraft and the pilot.

There are a lot of great design elements here, but for our money, we found the lightweight homebrew strain gauges to be the real gem of this design. This isn’t the first time [Andre] has flown onto these pages, either — his giant RC paraglider was a big hit back in January.

Thanks to [mip] for the tip.

Finally, a Differently Useless Machine

Traditionally, the useless machine is a simple one that invites passersby to switch it on. When they do, the machine somehow, some way, turns itself off; usually with a finger or finger-like object that comes out from the box in what feels like an annoyed fashion. Honestly, that’s probably part of what drives people to turn them on over and over again.

But [Bart Blankendaal] has managed to turn the useless machine on its head. When this machine is switched to the on position, unseen forces inside the box will spin the toggle switch around 180° to the off position.

What’s really happening is that an Arduino is getting a signal from the toggle switch, and is then rotating it on a ball bearing with a stepper motor driven through an H-bridge.

It shouldn’t be too hard to make one of these yourself, given that [Bart] has provided the schematic and STLs. If we weren’t living in such touchy times, we might suggest building one of these into your Halloween candy distribution scheme somehow. Sell the switch as one that turns on a candy dispenser, and then actually dispense it after three or five tries.

Many see useless machines as tangible examples of existential quandary. Here is one that takes that sentiment a bit further by snuffing out a candle.

Hacker Driven to Build R/C Forza Controller

Generic video game console controllers have certainly gotten better and more ergonomic since the hard corners of the Atari joystick. As beautiful and engrossing as games have become, the controller is still the least engaging aspect. Why race your sweet fleet of whips with an ordinary controller when you could pretend they’re all R/C cars?

[Dave] found an affordable 4-channel R/C controller in the Bezos Barn and did just that. It took some modifications to make it work, like making a daughter board to turn the thumb grip input from a toggle button to a momentary and figuring out what to do with the three-way slider switch, but it looks like a blast to use.

The controller comes in a 6-channel version with two pots on the top. Both versions have the same enclosure and PCB, so [Dave] already had the placement molded out for him when he decided to install a pair of momentary buttons up there. These change roles based on the three-way slider position, which switches between race mode, menu mode, and extras mode.

We love the way [Dave] turned the original receiver into a USB dongle that emulates an Xbox 360 controller — he made a DIY Arduino Pro Micro with a male USB-A, stripped down the receiver board, and wired them together. There’s an entire separate blog post about that, and everything else you’d need to make your own R/C controller is on GitHub. Check out the demo and overview of the controls after the break.

[Dave] is no stranger to making game controllers — we featured his DJ Hero controller modified to play Spin Rhythm XD a few months ago.

Via r/duino

Tiny Circuit Sculpture Keeps the Night Watch

If you’re planning to get into circuit sculpture one of these days, it would probably be best to start with something small and simple, instead of trying to make a crazy light-up spaceship or something with a lot of curves on the first go. A small form factor doesn’t necessarily mean it can’t also be useful. Why not start by making a small automatic night light?

The circuit itself is quite simple, especially because it uses an Arduino. You could accomplish the same thing with a 555, but that’s going to complicate the circuit sculpture part of things a bit. As long as the ambient light level coming in from the light-dependent resistor is low enough, then the two LEDs will be lit.

We love the frosted acrylic panels that [akshar1101] connected together with what looks like right angle header pins. If you wanted to expose the electronics, localize the light diffusion with a little acrylic cover that slips over the LEDs. Check it out in the demo after the break.

There’s more than one way to build a glowing cuboid night light. The Rubik’s way, for instance.

No Need for Speed with This Arduino-Based Inkjet Printer

When it comes to computers, it seems like the only thing that matters is speed. The more the better, in general, and the same applies to peripherals. We want the fastest network adapters, the fastest video card, and the fastest printer. So why in the world would anyone intentionally build a really slow inkjet printer? For art, of course.

At least that’s the story [HomoFaciens] tells us in the video below. His efforts are in support of a friend’s art project, which seeks to print slowly but continuously on a roll of paper. [HomoFaciens]’s printer is based on an H-P C6602 inkjet cartridge, one of those high-priced consumables that make buying a new printer more attractive than replacing them once depleted. After figuring out how to drive the printhead — 5 to 6 μs pulses of 18 volts through a ULN2803 Darlington array driver chip seemed to do the trick — he mounted everything to the gantry of an old 3D printer. It’s interesting to watch the images slowly being built up — something that printers usually hide from prying eyes — and to see how the DPI count of the printer can be increased by interlacing each printed line.

Near the end of the video, we get a glimpse of his “tattoo gun printer”, which reminded us of all the other cool things he’s done over the years. From a CNC machine made from paperclips and cardboard to an encoder made from a wheel of resistors, [HomoFaciens] has some interesting designs that you really should check out.

How Much Is That Plotter in the Window?

We live in a strange time indeed. People who once eschewed direct interactions with fellow humans now crave it, but to limited avail. Almost every cashier at the few stores deigned essential enough to maintain operations are sealed away behind plastic shields, with the implication that the less time one spends lingering, the better. It’s enough to turn an introvert into an extrovert, at least until the barriers are gone.

We get the idea that the need to reach out and touch someone is behind [Niklas Roy]’s “Please Leave a Message”, an interactive art installation he set up in the front window of his Berlin shop. Conveniently located on a downtown street, his shop is perfectly positioned to attract foot traffic, and his display is designed to catch the eye and perhaps crack a smile. The device consists of a large wooden easel holding the guts from an old X-Y pen plotter, an Arduino and an ESP-8266, and a couple of drivers for the plotter’s steppers. Passers-by are encouraged to scan a QR code that accesses a web page served up by the ESP-8266, where they can type in a brief message. The plotter dutifully spells it out on a scroll of paper for all to see, using a very nice font that [Niklas] designed to be both readable and easily plotted. The video below shows it in action with real people; it seems to be a crowd-pleaser.

[Niklas] has been incredibly prolific, and we’ve covered many of his interactive art installations. Just search for his name and you’ll find everything from a pressure-washer dancing waters display to a plus-sized pinball machine.

Hack a Day 14 May 16:30