Hackaday Links: March 12, 2017

The world’s first public installation of a solar roadway caught fire or something.

Hey hardware nerds in the UK! Nottingham is having its first monthly hardware meetup. This get together is being put together by [Spencer], creator of the extremely popular RC2014 Homebrew Z80 computer kit. The meetup is free, and it’s happening this Tuesday.

[danjovic] sent in a link to this YouTube channel of a guy building stuff out of PVC sheets and CA glue. There’s a lot of stuff in here from a PVC tripod to instructions on how to get PVC sheets out of PVC pipe. Small warning: this is PVC, and it will kill you instantly, for reasons we can’t yet determine. Additionally, he’s heating PVC, which means cancer for your yet-unborn great-grandchildren. How it both kills you while still allowing you to breed is beyond our comprehension. That’s how bad PVC really is.

NASA has updated their available software catalog. If you want to go to Saturn, you first have to go to Venus three times. Here’s a tool that packs batteries. You should build a router for the interplanetary Internet.

[jlbrian7] is Breaking Android over on Hackaday.io

Last week, we had a Raspberry Pi Hack Chat with [Roger Thornton], the principal hardware engineer at Raspberry Pi. We talked about the hardware that goes into the Raspberry Pi (and the new Pi Zero W), and gave away a few Pi Zero Ws to a few people on hackaday.io that had great ideas for a project. One of the winners of a free Raspberry Pi Zero W was [arsenijs] for his Raspberry Pi Project. This is a really great project that uses a Raspberry Pi and Raspberry Pi accessories. It’s pushing the envelope of what a Pi can be, and a free Raspberry Pi Zero W couldn’t have gone to a more worthy project.

What are you doing the weekend of March 31st? We’re going to New Jersey for the Vintage Computer Festival East. This is one of the better cons we go to. Maybe this year we’ll organize a trip to the pinball museum in Asbury Park.

Raspberry Pi-Based Game Boy Emulator

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

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

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.

Control Alexa Echo From Anywhere In The World

If you are not within ear-shot of your Alexa Echo, Dot or Tap device and need to command it from anywhere in the world, you’d most likely use the handy mobile app or web interface to control it. For some strange reason, if you’d rather use voice commands from anywhere in the world, you can still do it using apps such as Alexa Listens or Reverb, among many others. We’d be the first ones to call these out and say “It’s not a hack”. But [pat dhens] approach is above reproach! He has posted details on how to Remote Control the Alexa Echo from Anywhere in the World. Short version of the hack — he’s using a Raspberry Pi with a speaker attached to it which commands his Alexa Tap using a text-to-speech converter program.

The long version is short as well. The user uses a VPN, such as OpenVPN, to log in to their home network where the Alexa device is located. Then, use VNC to connect to the Raspberry Pi to access its shell. Finally, the user issues a text command which is converted to speech by the ‘festival‘ program on the Raspberry Pi. The output goes to an external speaker via the Raspberry Pi’s 3.5 mm audio out jack. And that’s all there is to it. You’ve just issued a voice command to your Alexa from across the world.

Maybe it will save your vocal chords from damage due to excessive hollering, we guess. He’s even made a short video to prove that it works. Now all it needs is a microphone to listen to Alexa, convert speech-to-text, and then transmit it back to you across the world to complete the cycle.

We’re not sure, but he thinks this hack will lead him to world domination. Good Luck with that.

Continue reading “Control Alexa Echo From Anywhere In The World”

Better Linux Through Coloring

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.

Continue reading “Better Linux Through Coloring”

Banana Phone Blocks Robocalls

Despite the implementation of the National Do Not Call Registry in the US (and similar programs in other countries), many robocallers still manage to get around the system. Whether they’re operating outside the law somehow (or they simply don’t care about it) there are some ways you can take action to keep these annoying calls from coming through. [Alex] is among those to take matters into his own hands and built a specialty robocall-blocking device.

Based on a Raspberry Pi, the “Banana Phone” is able to intercept incoming calls on standard land lines or VoIP phones. After playing a short message, the caller is asked to input a four-digit code. Once the code is correctly entered, the caller is presumed to be human, added to a whitelist, and then the Pi passes them on to the recipient. There are, however, some legitimate robocallers such as emergency services regarding natural disasters or utility companies regarding outages. For these there is a global whitelist that the Pi checks against and forwards these robocalls on to the recipient automatically.

This project was originally an entry into a contest that the Federal Trade Commission put on a few years ago for ideas about how to defend against robocalls. We covered it back then, but now there are full build instructions. Even though the contest is long over, the Banana Phone is still in active development so if you have a spare Pi lying around you can still set this up yourself. There are some other interesting ways to defend against robocalls as well, like including the “line disconnected” tone in your voicemail, for example.