Teensy Adds S/PDIF to Library

With Arduino library support on an ARM Cortex M4 processor, it’s no surprise that we’re fans of the Teensy 3.1. And lately, [Paul Stoffregen] has been building out the Audio Library for this platform, making it even more appealing to the synth / audio geeks among us. And now, with just the addition of a highfalutin LED and some software, the Teensy can output digital audio over optical fiber.

S/PDIF, and more specifically optical TOSLINK, uses LED light sent down an optical fiber to encode audio data. The advantage of this over any voltage-level signals (like with regular wires) is that the source and destination devices aren’t electrically connected at all, which gets rid of the dreaded ground loop hum and any RF interference.

An S/PDIF audio data stream is a bit complex, but if you’re interested [Micah Scott] has a fantastic dissection of it up on her blog. Of course, you don’t have to know anything about any of that to simply use S/PDIF with the Teensy Audio Library.

We love open source hardware and software because of the collaborations that make ultra-rapid development of niche stuff like this possible. You can follow along with the development of the Teensy’s S/PDIF capabilities on the PJRC forum. Contributor [Frank B] modestly claims that “everything was already on the internet”, but that doesn’t make it any less cool that they got from zero to working library in a few weeks. (And note the clever use of a precomputed lookup table for speed.)

LED_TOSLINK2On the hardware side, [Paul] has posted up his adapter board for a cheap, but very professional looking, optical TOSLINK sender. But if you’re feeling ghetto, you can simply use a red LED pointed just right into the optical cable.

The end result? Lossless transmission of CD-quality audio from an Arduino-esque microcontroller, sent on a beam of light, for less than the cost of a latté.

MAMEFrame – Sweet All In One Portable MAME System

Video game enthusiast [NEIN] loves MAME. The one thing he doesn’t like much about MAME is moving large heavy MAME cabinets around. So what do you do if you want to take your games on the road? [NEIN] decided to come up with a portable MAME solution that includes everything all in one box so there is virtually no set-up time to get playing. He calls it ‘The MAMEFrame‘.

It may appear that this is a standard 2-player DIY controller, however, it is anything but. The display is housed inside the encloure — a video projector that connects to the Raspberry Pi via an HDMI cable. [NEIN] opted to use a Raspberry Pi instead of a large PC to help keep things light and samll. It’s almost like the two were made for each other. The projector has a built in battery and USB port. The Raspberry Pi is powered by the 5 volts supplied from the projector’s USB port making this unit completely portable and wireless. Just plop it down on a table, point it at a wall and you’re ready to guide Pac-Man to level 256!

Did you know one of the very first Raspberry Pi hacks ever was a MAME build?

Continue reading “MAMEFrame – Sweet All In One Portable MAME System”

Observercade, Portable MAME System Of The Future.

[GarageMonkeySan] wrote in to tell us about his latest project. It’s a MAME arcade emulator, but not just any MAME arcade emulator, it is housed in a briefcase. And if that was not interesting enough, it was built in the style of the TV Show “Fringe”, specifically like the Observer briefcases. He calls it the Observercade.

The hard-shelled Samsonite briefcase was taken apart to assess the best way to move forward. A Sintra frame was added to the top half of the briefcase and would hold a scavenged laptop LCD screen. A monitor faceplate was then made from 1/16″ polystyrene sheet to fill the gap around the screen.

The bottom half of the case holds the remaining electronics, which consists of a Raspberry Pi Model B (running RetroPie), power supply, speakers and LCD driver board. They are all mounted to the bottom of the control surface which also supports the controller joystick and buttons. Notice that the buttons are labeled in Observer symbols. These symbols are as accurate as possible roughly translating to ‘credit’, ‘player’… etc. This is a wonderfully done project that shows [GarageMonkeySan] pays extreme attention to detail.

If the Observercade rings a bell, you may be remembering the project that gave [GarageMonkeySan] his inspirations: the Briefcade.

Continue reading “Observercade, Portable MAME System Of The Future.”

TubeNetRadio Project Modernizes 1959 Tube Radio

Years ago, [Luk] came across an old tube radio. He’s since wanted to convert it to an internet radio but never really got around to it. Now that we are living in the age when a micro computer can be had for a mere $35, [Luk] decided it was time to finish his long lost project.

He chose a Raspberry Pi for the brains of his project because it is an inexpensive and well documented product perfect for what he wanted to do. [Luk] had a goal, to modify the radio as little as possible in order to get it to play both internet radio and locally stored MP3s. The radio from 1959 is certainly old, but it had a feature you may not expect. It had an AUX input with a separate volume knob out front. As is the radio itself, the input was mono. To connect the Raspberry Pi to the radio, [Luk] had to make an 1/8th inch stereo to banana plug adapter, a great solution that did not require any modification to the original radio.

WiFi is accessed though an off-the-shelf USB wireless module. After evaluating tapping into a 5vdc source somewhere in the radio, it was decided to use a wall wart to power the Raspberry Pi. A plug for the wall wart was spliced in after the radio’s main on/off switch. That way the radio and Raspberry Pi both turn on and off together. There is plenty of room for all of these added components inside the radio’s case.

The RaspPi can be fully controlled over the WiFi network but has a couple buttons wired up to the GPIO pins for limited manual control. The buttons for these controls fit perfectly in the round vent holes in the back panel of the radio’s case. Although the buttons are visible, no permanent modifications had to be made! [Luk] reports that everything works great, as do the original functions of the radio.

RetroPie Meets Game Gear, Again

If you’re a fan of video game systems of yesteryear then you are probably familiar with RetroPie. For those who aren’t, RetorPie is a collection of software and video game emulators that can run on a Raspberry Pi. The package makes it easy to get your fix of old games without having to own a bunch of consoles or loose your breath blowing on cartridges.

[brooksyx] already had a broken Game Gear, Raspberry Pi and a 4.3 inch LCD screen kicking around so he thought it would be a good idea to put them together into a handheld RetroPie. Clearly, the new screen was not going to fit in the old screen’s place. The Game Gear’s case was cut and the bezel from the new LCD screen was epoxied in place, gaps filled and finally sanded.

RetroPie Game Gear

 

The screen is not the only modifications done to the case. Down on the bottom right of the case front [brooksyx] added 4 buttons for the N64 C-buttons. Out back the battery compartments and cartridge slot were filled in.

This project isn’t done yet and we are excited to see how it comes out. If you’re digging this RetroPie portable, you may like this Game Gear with an unmodified case or this large-screened Game Boy.

Scratch-Built Bar Top MAME Cabinet

Video game enthusiast [Mike] is all about the journey and not necessarily the destination. That is why he likes working on projects and documenting their progress with great detail. His bar top MAME machine is certainly no exception.

One of [Mike’s] goals was to see if he could keep the look and feel of a large arcade cabinet but scale it down so that it was portable. He started with drawing up a model in Sketchup. Once satisfied with the layout and making sure everything would fit, the side panels were cut out of pine boards and will only be clear-coated. The remaining panels are cut from MDF as they will be covered in a matching decorative vinyl wrap.

The control panel may look simple but a lot of thought went into it. Of course, there is a joystick but [Mike] chose to only use 4 game-play buttons. He did this to save space and estimates he’ll still be able to play 90% of the available MAME games. Those 4 buttons are illuminated and the MAME front end, Mala, was configured to light up only the functional buttons for the particular game being played. Front and center on the control board is a rotary encoder for playing games like Arkanoid or games requiring a steering wheel.

In the end this build came out pretty nice looking. His build log is a great reference to hit before starting your next arcade cabinet project.

Although [Mike] calls his MAME cabinet ‘mini’, it’s not the most mini we’ve seen here on Hackaday.

MAME now available in the Palms of your hand

Every kid dreams of having an arcade game at their house. When those kids grow up, they have a couple of options for getting that at-home arcade experience. They can either buy a one-game commercial game or build a multi-game MAME cabinet. Both options have the same disadvantage: they take up a bunch of space!

Arcade game-aholic, [lokesen], wanted to scratch his itch but do it with something a little less ‘big’ than a standard arcade cabinet. He came up with the only logical solution; a MAME computer stuffed inside an arcade controller.

A lot of thought went into the controller case, which is made from laser cut acrylic. It had to be large enough to allow a proper arcade-emulating spacing of the joystick and buttons as well as have room for a mini-ATX motherboard and 64gb SSD drive. The case also has provisions for a cooling fan and some exhaust vents. To finish off the case, wood grain veneer was applied to the sides.

[lokesen] chose this motherboard for a reason, it has several options of on-board video output; VGA, DVI and HDMI. Connecting this controller to any TV, monitor, or projector is a piece of cake.