Raspberry Pi

1886 Articles

Raspberry Pi-Based Game Boy Emulator

March 12, 2017 by 14 Comments

The most popular use for a Raspberry Pi, by far, is video game emulation. We see this in many, many forms from 3D printed Raspberry Pi cases resembling the original Nintendo Entertainment System to 3D printed Raspberry Pi cases resembling Super Nintendos. There’s a lot of variety out there for Raspberry Pi emulation, but [moosepr] is taking it to the next level. He’s building the smallest Pi emulation build we’ve ever seen.

This build is based on the Pi Zero and a 2.2″ (0.56 dm) ili9341 TFT display. This display has a resolution of 240×320 pixels, which is close enough to the resolution of the systems the Pi Zero can emulate. The Pi Zero and display are attached to a beautiful purple breakout board (shared on OSH Park) along with a few 5-way nav switches, a charger for a Lipo battery, and a few other bits and bobs.

Right now, [moosepr] is experimenting with adding sound to his board. It’s easy enough to get sound out of a Pi Zero — it’s just PWM coming from a few pins — but audio also needs an amp, a speaker, and more space on the board. To solve this problem, [moose] found a few piezo transducers from musical greeting cards. These are designed to be thin and as loud as possible, and attaching these directly to the PWM pins providing audio might just work. This is a project to keep an eye on, if only to see if cheap piezos work for low-fi audio in retro emulators.

An Ugly But Functional Pi Laptop

March 11, 2017 by 17 Comments

It’s got a face only its mother could love. Or a Hackaday writer, since this ugly e-waste laptop proudly sports a Jolly Wrencher on its back.

All joking aside, this is a great example of doing what you can with what you’ve got. [starhawk] is limited on funds, and a regular laptop is beyond his means. But being light in the wallet is no reason to go without when you can scrounge parts from friends and family. The base of the laptop is a mini USB keyboard, with the top formed mainly by a 7″ HDMI panel. The back of the display is adorned with a Raspberry Pi 3, a USB hub, a little sound dongle, and the aforementioned Jolly Wrencher. The whole thing is powered by a cast-off power supply brick — no exploding batteries to worry about!

Other Pi-based laptops we’ve covered may be sleeker, but we’ve got to admit that [starhawk]’s keyboard is probably the better choice for working on the next great American novel. And a Linux laptop for next to nothing? That’s a win in our book.

Putting Pi In Infrared Doohickies

March 10, 2017 by 8 Comments

The Raspberry Pi Zero W is a tiny, cheap Linux computer with WiFi. It’s perfect for Internet of Things things such as controlling ceiling fans, window blinds, LED strips, and judgmental toasters. This leads to an obvious question: how do you attach your ceiling fan and LED strips to a Pi Zero? A lot of these things already have infrared remotes, so why not build an infrared hat for the Pi? That’s what [Leon] did, and it’s Open Hardware with documentation.

[Leon]’s Anavi Infrared Pi Hat does exactly what you think it should do. There’s an IR receiver, two IR LEDs, and UART pins for debugging. That’s all you need to control infrared doohickies over the Internet, and [Leon] wrapped it up in a nice neat package that’s the same size as a Raspberry Pi Zero. Add on some documentation and you have something we rarely see: a project meant to be used by other people.

This focus on allowing people to actually use what [Leon] created can lead to only one cynical conclusion: he’s probably selling these things somewhere. The cynic is never surprised. [Leon] has a crowdfunding campaign going, that’s over 400% funded with a month to go. That’s okay, though: all the design files are available so if you want to build your own without supporting people who build useful devices, have at it.

Adding An External Antenna To The Raspberry Pi Zero W

March 7, 2017 by 22 Comments

Putting a complete WiFi subsystems on a single-board computer is no mean feat, and on as compact a board as the Zero W, it’s quite an achievement. The antenna is the tricky part, since there’s only so much you can do with copper traces.

The new Raspberry Pi Zero W’s antenna is pretty innovative, but sometimes you need an external antenna to reach out and touch someone. Luckily, adding an external antenna to the Zero W isn’t that tough at all, as [Brian Dorey] shows us. The Pi Zero W’s designers thoughtfully included solder pads for an ultra-miniature surface-mount UHF jack. The jack pads are placed very close to the long, curving trace that acts as a feedline to the onboard antenna. There’s even a zero ohm SMT resistor that could be repositioned slightly to feed RF to the UHF jack. A little work with a soldering iron and [Brian]’s Pi was connected to an external antenna.

[Brian] includes test data, but aside from a few outliers, the external antenna doesn’t seem to offer a huge advantage, at least under his test conditions. This speaks to the innovative design of the antenna, which [Roger Thornton] from the Raspberry Pi Foundation discussed during last week’s last week’s Hack Chat. Check out the archive for that and more.

Thanks to [theEngineer] for the tip.

Better Linux Through Coloring

March 7, 2017 by 6 Comments

Cyber security is on everyone’s minds these days. Embedded devices like cameras have been used by bad guys to launch attacks on the Internet. People worry about data leaking from voice command devices or home automation systems. And this goes for the roll-your-own systems we build and deploy.

Many network-aware systems use Linux somewhere — one big example is pretty much every Raspberry Pi based project. How much do you think about security when you deploy a Pi? There is a superior security system available for Linux (including most versions you’d use on the Pi) called SELinux. The added letters on the front are for “Security-Enhanced” and this project was originally started by the NSA and RedHat. RedHat actually has — no kidding — a coloring book that helps explain some of the basic concepts.

We aren’t so sure the coloring book format is really the right approach here, but it is a light and informative read (we didn’t stay in the lines very well, though). Our one complaint is that it doesn’t really show you anything in practice, it just explains the ideas behind the different kind of protections available in SELinux. If you want to actually set it up on Pi, there’s a page on the Pi site that will help. If you have an hour, you can get a good overview of using SELinux in the video below.

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Portable RetroPie Suitcase For Multiplayer On The Go!

March 5, 2017 by 11 Comments

Portable gaming — and gaming in general —  has come a long way since the days of the original Game Boy. With a mind towards portable multiplayer games, Redditor [dagcon] has assembled a RetroPie inside a suitcase — screen and all!

This portable console has almost everything you could need. Four controllers are nestled beside two speakers. Much of the power cabling is separated and contained by  foam inserts. The screen fits snugly into the lid with a sheet of rubber foam to protect it during transport.

Tucked behind the monitor rests the brains of this suitcase console: a Raspberry Pi and the associated boards. [Dagcon] resorted to using a dedicated sound card for the speakers, diverting the output from the HDMI port. An LCD screen controller was also necessary as the screen had been re-purposed from its previous life as a laptop screen. [Dagcon] offers some tips on how to go about accomplishing this yourself and a helpful Instructables link.

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The ‘All-Seeing Pi’ Aids Low-Vision Adventurer

March 4, 2017 by 12 Comments

Adventure travel can be pretty grueling, what with the exotic locations and potential for disaster that the typical tourist destinations don’t offer. One might find oneself dangling over a cliff for that near-death-experience selfie or ziplining through a rainforest canopy. All this is significantly complicated by being blind, of course, so a tool like this Raspberry Pi low-vision system would be a welcome addition to the nearly-blind adventurer’s well-worn rucksack.

[Dan] has had vision problems since childhood, but one look at his YouTube channel shows that he doesn’t let that slow him down. When [Dan] met [Ben] in Scotland, [Ben] noticed that he was using his smartphone as a vision aid, looking at the display up close and zooming in to get as much detail as possible from his remaining vision. [Ben] thought he could help, so he whipped up a heads-up display from a Raspberry Pi and a Pi Camera. Mounted to a 3D-printed frame holding a 5″ HDMI display and worn from a GoPro head mount, the camera provides enough detail to help [Dan] navigate, as seen in the video below.

The rig is a bit unwieldy right now, but as proof of concept (and proof of friendship), it’s a solid start. We think a slimmer profile design might help, in which case [Ben] might want to look into this Google Glass-like display for a multimeter for inspiration on version 2.0.

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