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.

Putting new into the old – a Phonograph upgrade.

[smellsofbikes] recently came into possession of a 1970’s “stereo radio phonograph” cabinet consisting of a vinyl record player, AM and FM radio, and eight track tape player. The radio worked, the turntable didn’t sound too nice, and the tape player didn’t work at all. A new needle fixed the turntable, but the eight-track was in bad shape. So he replaced the tape player with a BeagleBoneBlack which plays streaming internet radio.

Hopefully, this fix is temporary, since he has carefully disconnected the tape player connections in the hope of fixing it soon. The swap out involved a fair bit of engineering, so he’s split his build log into several bite sized chunks. The first step was to set up the BBB, upgrade it and add in all the network and audio related stuff. Audio on the BBB is available only via the HDMI port, but [smellsofbikes] had a USB soundcard handy, so the next step was setting that up. He installed mpg321 – the command line mp3 player and set it up to play music streaming from somafm. Next up was getting some scripts and programs to run automatically during system bootup. The final part of the setup was adding a WiFi router as a repeater connected to the BBB via an ethernet cable. He could have used a tiny WiFi USB dongle, but he already had the router lying around, and he wanted to dedicate USB to audio functions alone, and use the Ethernet port for Internet.

He then worked on identifying the wires that go from the tape player to the amplifier, spliced them, and hooked them up to the audio sound card on the BBB. With this done, the upgrade was more or less complete – the system played streaming music and stations could be switched remotely (via SSH to BBB). [smellsofbikes] reckoned it would be nice to use the existing controls in the phonograph cabinet to control the internet streaming music, instead of controlling it via a remote computer. The cabinet had 4 indicator lamps that indicated which track was being played and a button to switch between tracks. He removed the old indicator panel and put in a fresh PCB, designed in KiCad and cut on his LPKF circuit board plotter. An aluminum knob machined out of hex bar-stock works as the new track change button. At this point, he called it a wrap. The BBB and Asus router go inside the cabinet, and the old (non-functional) tape player is put in place. Quite an interesting build, and we look forward to when he actually gets the tape player working. [Alan Martin], aka “The Most Interesting Engineer In The World” has told him that “it is a moral imperative that you repair the eight-track and get it working”. [Alan] has promised to send [smellsofbikes] a suitcase full of brand new, still in their plastic wrappers, eight-track tapes when he gets it working.

HDMI Splitter is also a Decrypter

It warms our hearts when the community gets together. [esar] needed to get a decrypted HDMI stream for his home theater system. A tip-off in the comments and a ton of good old-fashioned hacking resulted in a HDMI splitter converted into a full-featured HDMI decrypter. Here’s the story.

His amazing custom Ambilight clone got profiled here, and someone asked him in the comments if it worked when High-bandwidth Digital Content Protection (HDCP) is on. [esar] lamented that it didn’t. Hackaday readers to the rescue. [Alan Hightower] and [RoyTheReaper] pointed [esar] to the fact that HDMI splitters need to decrypt and re-encrypt the signal to pass it on, and pointed him to a trick to knock out the on-board microcontroller. [esar] took off from there.

Unfortunately, taking the micro out of the picture messed with a lot of other HDMI functionality. So [esar] started digging in the datasheets for the HDMI splitter chip, looking for registers relevant to the re-encryption. If he could get in between the microcontroller and the splitter chip on the I2C bus and disable the re-encryption, he’d be set.

If you’re at all interested in I2C hacking or abusing HDMI splitters, you need to read his post because he details all of the tribulations and triumphs. He first tries just brute-forcing the I2C by overwriting a 1 bit with a 0. This (correctly) signals the micro that there’s been a conflict on the bus, so it re-sends the command again. Dead end.

He then found another signal that the receiver could use say that it wasn’t decrypting. He tried sending this continuously to the splitter so that it would stop encrypting. That worked, but only for one channel, some of the time. It turns out that his code was taking too long in his bit-banged I2C code. He fixes this up and all is well? Well, 90% of the way there.

To hammer down the last 10% of the functionality, [esar] buys a couple more splitters, experiments around with another splitter chipset that works with 3D, and solders some more wires to enable the Audio Return Channel. And after a ton of well-documented hard work, he wins in the end.

DIY Turntable In A Beautiful Wooden Case

Old timers who have been around for the last 40 years or so have been fortunate enough to have lived through several audio reproduction technologies – Vinyl Records, Cassette Tapes, Laser Disks and CD-ROM’s. Most will also swear that analog, especially vinyl records, sounded the best. And when it comes to amplifiers, nothing comes close to the richness of vacuum tubes.

[MCumic10] had a long time desire to build his own HiFi turntable encased in a nice wooden housing, with the electronics embedded inside. When he chanced upon an old and battered turntable whose mechanism barely worked, he decided to plunge right in to his pet project. The result, at the end of many long months of painstaking work, is a stunning, beautiful, wooden turntable. Especially since in his own words, “I didn’t have any experience in electronics or woodworking before I started this project so it took me many long months in learning analyzing and frustration. I burned some electronic parts few times and made them from the beginning.”

The build is a mix of some off the shelf modules that he bought off eBay and other sources, and some other modules that he built himself. He’s divided the build in to several bite sized chunks to make it easy to follow. The interesting parts are the 6N3 Valve Preamplifier (the main amplifier is solid-state), the motorized Remote Volume Control Input kit, and the Nixie tube channel indicator. And of course the layered, plywood casing. By his own reckoning, this was the toughest and longest part of his build, requiring a fairly large amount of elbow grease to get it finished. He hasn’t yet measured how much it tips the scales, but it sure looks very heavy. The end result is quite nice, especially for someone who didn’t have much experience building such stuff.

Thanks [irish] for sending in this tip.

EVA: What’s on Telly for the Visually Impaired

[chewabledrapery] has certainly used his Raspberry Pi for good. His girlfriend’s grandfather is growing more visually impaired as time goes on. He likes to watch telly, but has trouble reading the on-screen information about the channel and programming. To that end, [chewabledrapery] has built an electronic voice assistant called EVA, who fetches the telly schedule from a web service and reads it aloud in her lovely voice that comes courtesy of Google Translate’s TTS function.

Under EVA’s hood is a Raspberry Pi. A USB hub powers the Pi and holds a small USB soundcard, a Wi-Fi dongle, and a USB daughterboard that the controller plugs into. The daughterboard is from a USB keyboard, which makes another appearance in the awesome controller. It’s made of a joystick and two arcade buttons that use the USB keyboard’s controller to interact with Python scripts.

[chewabledrapery]’s scripts make formatted requests to a web service called atlas, which returns JSON objects with the TV schedule and content descriptions. EVA then turns to Google Translate, speaking the formatted text through a small amplifier and salvaged PC speaker. In order to minimize the number of web calls, some of EVA’s frequent musings are stored locally. A full tour of EVA is after the break.

We love to see hacks that help people. Remember this RFID audio book reader?

Continue reading “EVA: What’s on Telly for the Visually Impaired”

Calculator + MSP430 + IR LED = TV Remote?

Eschewing the store-bought solution, [Stefan] managed to build a TV remote out of an old calculator. The brains of the calculator were discarded and replaced with an MSP430, leaving only the button matrix and enclosure. Rather than look it up, he successfully mapped the matrix manually before getting stumped with the infrared code timings. Some research pointed him to a peculiarity with Samsung IR codes and with help from an open source remote control library he got it working.

When the range was too limited to satisfy him he added a booster circuit and an LED driver which he snapped off the top of an old remote; now it works from 30 feet away. Some electrical tape and hot glue later and it all fit back into the original case.

It cannot take photos or play Super Smash Brothers, but it does what a remote needs to do: browses channels in the guide, control volume, and turn the TV on or off. Considering that all this calculator was built to do was boring basic arithmetic, it is a procrastination-enabling upgrade.

See the video after the break for some smiles.

Continue reading “Calculator + MSP430 + IR LED = TV Remote?”