Cramming a Pi Zero into a Cheap Handheld Game

At this point, we’ve seen the Raspberry Pi jammed into what amounts to every retro game system, handheld or otherwise, that was ever released. While they’re always fun builds, invariably somebody will come along who is upset that the original hardware had to be gutted to create it. It seems as if with each post, a classic gaming aficionado out there has his or her heart broken just a bit more. Will no one put an end to the senseless slaughter of Game Boys?

As it so happens, not all hardware modders are such unconscionable brutes. [Starfire] recently sent his latest creation into the tip line, and it’s designed specifically to address the classic gaming massacre in which Hackaday has so shamefully been a collaborator.  His build sacrifices a portable Genesis built by AtGames, and turns it into a Raspberry Pi Zero portable running RetroPie.

Opening up the back panel of his portable Pi shows an incredible amount of hardware smashed into the tiny package. Beyond the obvious Pi Zero, there’s a iUniker 2.8-inch LCD, a 2,200 mAh battery, a two-port USB hub, a Teensy microcontroller, a USB sound card, an audio amplifier, a LiPo charging module, and a boost converter. [Starfire] measured peak power consumption to be 500 mA, which should give about a 3.5 hour run time on the 2,200 mAh battery.

This is all the more impressive when you realize the original AtGames PCB is still in the system, albeit with the center cut out for the Pi’s LCD to fit in. Rather than having to figure out a new way to handle input, [Starfire] simply connected the existing inputs to the digital pins on the Teensy and used some code to convert that into USB HID for the Pi. A few case modifications were necessary, namely the removal of the battery compartment from the back panel and covering up the original SD card slot and ports; but otherwise the finished product looks completely stock.

If you don’t mind tearing into a real Game Boy to make your portable Pi, you can check out a few of the stand out examples which we’ve covered here in the past.

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Glitch Delays And Teensy Audio

With the release of the Teensy 3.6 and the associated audio processing libraries, it’s never been a better time to get into DIY synth and effects projects. [Scott] is a musician and maker of electronic musical instruments, so he decided to leverage the power of the Teensy and make a delay module that really can’t be done any other way.

The function of this delay module is somewhat similar to a multi-head tape-based delay, only it’s completely impossible outside of the digital domain. There are four ‘read heads’ on a circular buffer. The first three heads play small loops within the buffer at different speeds, one at the original speed, one at half speed (and an octave below) and one at double speed (and an octave above). The fourth head doesn’t loop, instead, it plays the delay buffer in reverse. There are, of course, handy knobs for setting the level of each ‘read head’.

This project is built around [Scott]’s port of the JUCE framework, a very powerful audio API that’s now well suited for laptop and embedded development. The files for this project are all available on the GitHub, and [Scott] plans to build an expansion module for CV control of all the parameters.

So, how does this glitch delay sound? Pretty good. The video below is just a tele into a looper pedal, and into the glitch delay. There are surely some ambient post-rock stars wetting their skinny jeans over this one, and it’s a great application of the Teensy’s audio processing power, to boot.

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Eight SEGAs Singing

Way back in the dark ages, before the average computer could play back high quality recorded audio, things were done differently. Music and sounds were stored as instructions to be played back on audio synthesis chips, built into the computers and consoles of the 80s and 90s. These chips and their unique voices hold a special nostalgia that’s key to this era, making them popular to experiment with today. To that end, [little-scale] decided to wire up eight chips from the SEGA Master System to please your ears.

The chips, laid out on a breadboard with a Teensy LC running the show.

The chip in question is the SN76489, which we’ve also noted is used in the Sega Genesis as well. It packs 3 square wave tone generators, and a noise channel as well. With eight of these to play with, that’s 32 total channels. To drive these, [little-scale] decided to go the MIDI route. To get around the MIDI limit of 16 channels, he decided to split the frequency range in half. Each MIDI channel addresses two SN76489 channels, the top pitches being used for one, the lower pitches being used for the other. All this MIDI data is passed to a Teensy LC, which handles transposition of the note data to get everything back in tune, and addresses the eight chips to create a beautiful square wave symphony.

It’s a great way to create a cacophony of sound in a delightful vintage way, and code is available if you’d like to recreate the feat. What we’d like to know is this – what’s your favourite sound chip from yesteryear, and how badly do you want eight of them to sing in glorious harmony? Continue reading “Eight SEGAs Singing”

Ergonomic Keyboard Designed from the Ground Up

In 2011, [Fabio] had been working behind a keyboard for about a decade when he started noticing wrist pain. This is a common long-term injury for people at desk jobs, but rather than buy an ergonomic keyboard he decided that none of the commercial offerings had all of the features he needed. Instead, he set out on a five-year journey to build the perfect ergonomic keyboard.

Part of the problem with other solutions was that no keyboards could be left in Dvorak (a keyboard layout [Fabio] finds improves his typing speed) after rebooting the computer, and Arduino-based solutions would not make themselves available to the computer’s BIOS. Luckily he found the LUFA keyboard library, and then was able to salvage a PCB from another keyboard. From there, he programmed everything on a Teensy microcontroller, added an OLED screen, and soldered it all together (including a set of Cherry MX switches).

Of course, the build wasn’t truly complete until recently, when a custom two-part case was 3D printed. The build quality and attention to detail in this project is impressive, and if you want to roll out your own [Fabio] has made all of the CAD files and software available. Should you wish to incorporate some of his designs into other types of specialized keyboards, there are some ideas floating around that will surely improve your typing or workflow.

Pocket Woodwind MIDI Controller Helps You Carry a Tune

It’s easy to become obsessed with music, especially once you start playing. You want to make music everywhere you go, which is completely impractical. Don’t believe me? See how long you can get away with whistling on the subway or drumming your hands on any number of bus surfaces before your fellow passengers revolt. There’s a better way, and that way is portable USB MIDI controllers.

[Johan] wanted a pocket-sized woodwind MIDI controller, but all the existing ones he found were too big and bulky to carry around. With little more than a Teensy and a pressure sensor, he created TeensieWI.  It uses the built-in cap sense library to read input from the copper tape keys, generate MIDI messages, and send them over USB or DIN. Another pair of conductive pads on the back allow for octave changes. [Johan] later added a PSP joystick to do pitch bends, modulation, and glide. This is a simple build that creates a versatile instrument.

You don’t actually blow air into the mouthpiece—just let it escape from the sides of your mouth instead. That might take some getting used to if you’ve developed an embouchure. The values are determined by a pressure sensor that uses piezoresistivity to figure out how hard you’re blowing. There’s a default breath response value that can be configured in the settings.

TeensiWI should be easy to replicate or remix into any suitable chassis, though the UV-reactive acrylic looks pretty awesome. [Johan]’s documentation on IO is top-notch and includes a user guide with a fingering chart. For all you take-my-money types out there, [Johan] sells ’em ready to rock on Tindie. Check out the short demo clips after the break.

We saw a woodwind MIDI controller a few years ago that was eventually outfitted with an on-board synthesizer. Want to build a MIDI controller ? , like this beautiful build that uses hard drive platters as jog wheels.

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DIY Multi-Touch All the Surfaces

Ever wanted to build a touch table or other touch-input project, but got stuck figuring out the ‘touch’ part? [Jean Perardel] has your back with his multi-touch frame over on IO that makes any surface touch-reactive. In [Jean]’s case, that surface is ultimately a TV inside of a table.

Of course, it’s a bit of a misnomer to say the surface itself becomes touch-reactive. What’s really happening here is that [Jean] is using light triangulation to detect shadows and determine the coordinates of the shadow-casting object. Many barcode scanners and consumer-level document scanners use a contact image sensor (CIS) to detect objects in the path of IR LEDs. These are a low-power, lower-resolution alternative to the CCDs found in high-grade scanners.

As [Jean] explains in the video below, an object placed in the path of a single IR LED facing a sensor array of either type will block the light from reaching the sensors. Keep adding LEDs and their emission angles will begin to overlap, increasing the detection precision. [Jean] reverse engineered a couple of different types of scanners until he found a suitable one. He ended up with CIS that has 2700 light sensors lined up in the space of 20cm (7.87″).

[Jean] designed a 3D-printable frame to hold 96 IR LEDs in stacks of three. A Teensy turns on the LEDs, detects the touch event, calculates the position, and sends those coordinates to a Pi to be displayed on the screen. He eventually went wireless and then built a nice looking touch table to house a 32″ TV.

This is not the only way to build a multi-touch table, nor is it the simplest. Here’s one that uses finger presses to scatter light and an industrial strength projection-based table that was open-sourced a few years ago.

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DIY Nintendo Switch May Be Better Than Real Thing

Nintendo’s latest Zelda-playing device, the Switch, is having no problems essentially printing money for the Japanese gaming juggernaut. Its novel design that bridges the gap between portable and home console by essentially being both at the same time has clearly struck a chord with the modern gamer, and even 8 months after its release, stores are still reporting issues getting enough of the machines to meet demand.

But for our money, we’d rather have the Raspberry Pi powered version that [Tim Lindquist] slaved over for his summer project. Every part of the finished device (which he refers to as the “NinTIMdo RP”) looks professional, from the incredible job he did designing and printing the case down to the small details like the 5 LED display on the top edge that displays volume and battery level. For those of you wondering, his version even allows you to connect it to a TV; mimicking the handheld to console conversion of the real thing.

[Tim] has posted a fascinating time-lapse video of building the NinTIMdo RP on YouTube that covers every step of the process. It starts with a look at the 3D model he created in Autodesk Inventor, and then goes right into the post-printing prep work where he cleans up the printed holes with a Dremel and installs brass threaded inserts for strength. The bulk of the video shows the insane amount of hardware he managed to pack inside the case, a true testament to how much thought was put into the design.

For the software side, the Raspberry Pi is running the ever popular RetroPie along with the very slick EmulationStation front-end. There’s also a Teensy microcontroller on board that handles the low-level functions such as controlling volume, updating the LED display, and mapping the physical buttons to a USB HID device the Raspberry Pi can understand.

The Teensy source code as well as the 3D models of the case have been put up on GitHub, but for a project like this that’s just the tip of the iceberg. [Tim] does mention that he’s currently working on creating a full build tutorial though; so if Santa doesn’t leave a Switch under the tree for you this year, maybe he can at least give you a roll of filament and enough electronics to build your own.

While this isn’t the first time a Raspberry Pi has dressed up as a Nintendo console, it may represent the first time somebody has tried to replicate a current-generation gaming device with one.

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