Raspberry Pi

1951 Articles

Raspberry Pi Hitches Ride Inside Vintage Terminal

March 13, 2017 by 41 Comments

When a dumpster dive yielded a vintage video display terminal, [dennis1a4] knew just what to do — bring the Heathkit H19 back to life and stuff a Raspberry Pi inside.

The early days of the personal computer era were a time of great market diversity. Everyone was making stuff needed to cobble together your perfect computer, and terminals were among the most important pieces of gear. Lear Siegler, DEC, Wyse — everyone was in on the game. Even Heathkit competed with its H19 serial terminal, which would have set you back a thousand or so early-1980s dollars.

The terminal [dennis1a4] found was DOA, but he quickly determined that a bad cap was shorting out the -12VDC rail. A little extra detective work was needed to get the terminal to both echo characters locally and output them over the RS-232 port, and bam, working terminal. But then what? Raspberry Pi to the rescue! But those old school +/-12 volts swings would give a Pi a bad case of Blue Smoke Disease. After a little voltmeter poking, and through the magic of socketed driver chips, the Pi was talking right to the terminal at a screaming 9600 baud and accessing the Hackaday Retro site on the 80-by-24 mono display.

All in all, a nice hack on a piece of computer history. But just one question: Can it play Doom Flappy Bird?

Q Has Nothing On Naomi Wu

March 12, 2017 by 185 Comments

We’re not so much fans of James Bond as we are of Q, the hacker who supplies him with such wonderful things. There is a challenger to Q’s crown, [Naomi Wu] — code name [SexyCyborg] — built an epic gadget called the Pi Palette which hides a Linux laptop inside of a cosmetics case.

You can see the covert mode of the Pi Palette below. It resembles a clamshell cosmetics case with the makeup and applicator in the base and a mirror on the underside of the flip-up lid. The mirror hides an LCD screen in the portrait orientation, as well as a Raspberry Pi 3 running Kali Linux.

The base of the case includes a portable battery beneath the wireless keyboard/touchpad — both of which are revealed when the cosmetics tray is removed. An inductive charger is connected to the battery and [Naomi] built a base station which the Pi Palette sits in for wireless charging.

She envisions this as a covert penetration testing. For that, the Pi Palette needs the ability to put the WiFi dongle into promiscuous mode. She wired in a dual dip-switch package and really went the extra mile to design it into the case. The fit and finish of that switch is just one tiny detail the illustrates the care taken with the entire project. With such a beautiful final project it’s no wonder she took to the streets to show it off. Check that out, as well as the build process, in the video after the break.

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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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