Barcode Guitar Plays More Than Beep-Bop

One of our favorite things about the rise of hobbyist development ecosystems such as the Arduino is that it’s now possible to make a MIDI controller out of almost anything, as long as you have the the shields and the dedication. We’re glad that [James Bruton] takes the occasional break from making robots to detour into instrument making, because his latest creation turns it up to 11.

This awesome guitar uses a barcode scanner to play notes, and various arcade controls to manipulate those notes. The barcodes themselves scan as ASCII values, and their equivalent integers are sent to an external MIDI device. This futuristic axe is built on an Arduino Mega, with a USB shield for the barcode scanner, and a MIDI shield on top that [James] connects to various synths in the video after the break.

In between shooting barcodes, the right hand also controls octave shifting and changing MIDI channels with the joystick, and doing pitch-bends with the rotary encoder. The array of arcade buttons on the bottom neck let him switch between single player for monophonic synths, and multiplayer for polys. The other three buttons are press-and-scan programmable single-note sounders that assist in chord-making and noodling.

We particularly dig the construction, which is a combination of 20/20 and 3D printed boxes. [James] found some angled PVC to serve as fretboards for the four necks, and a nice backgrounds for bar codes.The only thing we would change is the native beep of the barcode scanner — either silence it forever or make it mutable, because it doesn’t jive with every note. It might be nice to get the gun to scan continuously so [James] doesn’t get trigger finger. Or better yet, build the scanner into a glove.

Want to do something more useful with that barcode scanner in your parts bin? Use it to manage your household inventory. But first, reacquaint yourself with the history of the humble barcode as presented by [Adam Fabio].

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Handheld LoRa Joystick For Long-Range Bots

Wanting a simple tool to aid in the development of LoRa controlled robotic projects, [Jay Doscher] put together this very slick one-handed controller based on the 900 MHz Adafruit Feather M0. With a single trigger and a miniature analog joystick it’s a fairly simple input device, but should be just enough to test basic functionality of whatever moving gadget you might find yourself working on.

Wiring for this project is about as simple as you’d expect, with the trigger and joystick hanging off the Feather’s digital ports. The CircuitPython code is also very straightforward, though [Jay] says in the future he might expand on this a bit to support LoRaWAN. The controller was designed as a barebones diagnostic tool, but the hardware and software in its current form offers an excellent opportunity to layer additional functionality on a known good base.

Everything is held inside a very well designed 3D printed enclosure which [Jay] ran off on his ELEGOO Mars, one of the new breed of low-cost resin 3D printers. The machine might be pretty cheap, but the results speak for themselves. While resin printing certainly has its downsides, it’s hard not to be impressed by the finish quality of this enclosure.

While LoRa is generally used for transmitting small bits of information over long distances, such as from remote sensors, this isn’t the first time we’ve seen it used for direct control of a moving object. If you’re not up to speed on LoRa, check out this excellent talk from [Reinier van der Lee] that goes over the basics of the technology and how he used it to build a community sensor network.

See If Someone Has Been In Your Drawers With This Simple Alarm

There’s a spy movie – probably from the [James Bond] franchise – in which our hero is staying in a fancy hotel. It’s crawling with enemies, naturally, and eager to see if one has been snooping in his room while he’s out for martinis, he sticks a hair across the gap in the door. When he comes back and finds the hair missing, he knows the game is afoot.

This hotel safe intrusion detector is what [Q] might have thought up for such a job if he’d had access to PIC microcontrollers and SMD LEDs. [Andy]’s “LightSafer” is a silent alarm for hotel safes, drawers, closets, or even the refrigerator – anywhere where the transition from dark to light indicates an unwanted visit. It’s tiny – only 33 x 21 mm – and is powered by a CR2032 coin cell. A Broadcom APDS-9300 light sensor watches for openings while the PIC monitors a joystick control for the correct PIN entry. There’s no audible alarm; rather, an LED blinks to indicate an unauthorized intrusion and blinks once for every 15 minutes since the event.

LightSafer is simple but effective, with a clever UI that keeps the current draw low and the battery life long. [Andy] used a similar technique for this low-draw cat tracking collar that we featured a while back.

Up Your Game With A Battle Tested Input Device

If you’re looking to add some realism to your flight setup without converting the guest bedroom into a full-scale cockpit simulator, you might be interested in the compromise [MelkorsGreatestHits] came up with. He bolted a genuine military keypad to his PC joystick and instantly added 100% more Top Gun to his desktop.

The Rockwell Collins manufactured keypad came from eBay, and appears to have been used in aircraft such as the EA-6B Prowler and Lockheed C-130 Hercules for data input. Each key on the pad is wired to the 37 pin connector on the rear, which [MelkorsGreatestHits] eventually mapped out after some painstaking work with a breakout board.

Once the matrix was figured out, he made up a cable that would go from the connector to a Teensy 2.0 microcontroller. The Teensy reads the keypad status and converts button presses over to standard USB HID that can be picked up in any game.

The joystick side of the build is a VKB Gunfighter, which is already a pretty nice piece of kit on its own. No modifications were necessary to the joystick itself, other than the fact that it’s now mounted to the top of a black project enclosure. It still connects directly to the computer via its original USB cable, as the keypad has its own separate connection. As luck would have it, the joystick is almost a perfect fit in the opening on the keypad, which presumably would have been for a small screen when installed in the aircraft.

Finding cockpit components from military aircraft on eBay is not as hard as you may think; something to keep in mind if you ever decide to tackle that custom flight simulator build.

DIY Six Channel Arduino RC Transmitter

It’s wasn’t so long ago that RC transmitters, at least ones worth owning, were expensive pieces of gear. Even more recently than that, the idea of an RC transmitter running an open source firmware would have been considered a pipe dream. Yet today buying cheap imported transmitters and flashing a community developed firmware (if it didn’t come with it pre-installed to begin with) is common place. It’s not much of a stretch to say we’re currently in the “Golden Age” of hobby RC transmitters.

But what if even cheap hardware running customizable software isn’t enough? What if you want to take it to the next level? In that case, [Electronoobs] has an Arduino powered RC transmitter with your name on it. But this is no scrap of protoboard with a couple of cheap joysticks on it, though he has made one of those too. The goal of this build was for it to look and perform as professional as possible while remaining within the hobbyist’s capabilities. The final product probably won’t be winning any design awards, but it’s still an impressive demonstration of what the individual hacker and maker can pull off today with the incredible technology we have access to.

So what goes into this homebrew radio control system? Inside the back panel [Electronoobs] mounted the batteries, charging module, and the voltage regulator which steps the battery voltage down to the 3.3 V required to drive the rest of the transmitter’s electronics. On the flip side there’s an Arduino Nano, an NRF24 module, and an OLED display. Finally we have an assortment of switches, buttons, potentiometers, and two very nice looking JH-D202X-R2 joysticks for user input.

As you might have guessed, building your own transmitter means building your own receiver as well. Unfortunately you won’t be able to bind your existing RC vehicles to this radio, but since the receiver side is no more complicated than another Arduino Nano and NRF24 module, it shouldn’t be hard to adapt them if you were so inclined.

Low-cost consumer RC transmitters can be something of a mixed bag. There are some surprisingly decent options out there, but it’s not a huge surprise that hackers are interested in just spinning up their own versions either.
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3D-Printed Rotary Dial Keypad Is Wonderfully Useless

Right up front, let us stipulate that we are not making fun of this project. Even its maker admits that it has no practical purpose. But this 3D-printed Commodore-style rotary dial keypad fails to be practical on so many levels that it’s worth celebrating.

And indeed, celebrating deprecated technology appears to be what [Jan Derogee] had in mind with this build. Rotary dials were not long ago the only way to place a call, and the last time we checked, pulse dialing was still supported by some telephone central office switchgear. Which brings us to the first failure: with millions of rotary dial phones available, why build one from scratch? [Jan] chalks it up to respect for the old tech, but in any case, the 3D-printed dial is a pretty good replica of the real thing. Granted, no real dial used a servo motor to return the dial to the resting state, but the 3D-printed springs [Jan] tried all returned the dial instantly, instead of the stately spin back that resulted in 10 pulses per second. And why this has been done up VIC-20 style and used as a keypad for Commodore computers? Beats us. It had to be used for something. That the software for the C-64  generates DTMF tones corresponding to the number dialed only adds to the wonderful weirdness of this. Check out the video below.

We’ll hand it to [Jan], he has a unique way of looking at the world, especially when it comes to clocks. We really enjoyed his persistence of phosphorescence clock, and his screw-driven linear clock turns the standard timekeeping UI on its head.

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The Rotary Joystick Can Take A Beating

It’s a well-known fact amongst the older set that games used to be harder. Back in the 1980s, most home computers had awful keyboards, barely adequate joysticks, and the games had to be difficult to have any longevity, because there’s only so much you can fit into a single sided disk. Some of these games became known as joystick killers, due to the repetitive thrashing movements required to win. [Jan] was tired of letting Decathlon and its ilk get the better of him and his controllers, so built a joystick that was up to the task.

The basic concept of [Jan]’s rotary joystick is that many games required a fast and repetitive left-right motion to be executed by the player, but weren’t too concerned if a few up or down movements were in the mix. Thus, instead of a traditional shaft-based joystick, instead a rotary mechanism was employed. The player rotates the joystick’s wheel, which has a magnet fitted. This triggers a series of four reed switches, for up, down, left and right. By rotating the wheel quickly, it simulates the rapid left-right motion well enough to beat most of the vintage C64 games that were giving [Jan] trouble, and it makes an ideal controller for the 2018 release, Crank Crank Revolution.

We like the spirit behind any build that uses hardware to overcome intractable gaming problems. We’ve seen similar approaches used to beat Guitar Hero.¬†Remember Guitar Hero? That was a thing. Video after the break.

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