Meet MutantC: Raspberry Pi Sidekick Complete With Sliding Screen, QWERTY

September 30, 2019 by Tom Nardi 29 Comments

Over the years we’ve seen the Raspberry Pi crammed into almost any piece of hardware you can think of. Frankly, seeing what kind of unusual consumer gadget you can shoehorn a Pi into has become something of a meme in our circles. But the thing we see considerably less of are custom designed practical enclosures which actually play to the Pi’s strengths. Which is a shame, because as the MutantC created by [rahmanshaber] shows, there’s some incredible untapped potential there.

The MutantC features a QWERTY keyboard and sliding display, and seems more than a little inspired by early smartphone designs. You know, how they were before Apple came in and managed to convince every other manufacturer that there was no future for mobile devices with hardware keyboards. Unfortunately, hacking sessions will need to remain tethered as there’s currently no battery in the device. Though this is something [rahmanshaber] says he’s actively working on.

The custom PCB in the MutantC will work with either the Pi Zero or the full size variant, but [rahmanshaber] warns that the latest and greatest Pi 4 isn’t supported due to concerns about overheating. Beyond the Pi the parts list is pretty short, and mainly boils down to the 3D printed enclosure and the components required for the QWERTY board: 43 tactile switches and a SparkFun Pro Micro. Everything is open source, so you can have your own boards run off, print your case, and you’ll be well on the way to reliving those two-way pager glory days.

We’re excited to see where such a well documented open source project like MutantC goes from here. While the lack of an internal battery might be a show stopper for some applications, we think the overall form factor here is fantastic. Combined with the knowledge [Brian Benchoff] collected in his quest to perfect the small-scale keyboard, you’d have something very close to the mythical mobile Linux device that hackers have been dreaming of.

Continue reading “Meet MutantC: Raspberry Pi Sidekick Complete With Sliding Screen, QWERTY” →

Keeping Kids In School The Smart Way

September 30, 2019 by Sharon Lin 44 Comments

For institutions with high traffic, such as schools and movie theaters, it can be difficult to keep track of individuals moving in and out, especially without a critical mass of security. For schools especially, keeping track of student attendance and preventing kids from leaving campus in the middle of the day can be a costly problem.

The solution that Tunisian engineers [Michael Djimeli], [Darius Koliou], and [Jinette Tankoua] came up with was to create a smart gate that only turns when checks are carried out by designated security officers. The design is retrofitted to existing school turnstiles in his hometown of Monastir, Tunisia, and uses an RFID card, biometric devices, and a host of access controls to ensure that the student attempting to turn the turnstile is validated first.

The smart gate uses a few methods for identification – either by RFID, fingerprint, facial recognition, or by reading a QR code. An external database stores each user’s data and their transaction history, effectively storing their attendance data. In addition to relaying the information to an administrator, the smart gate also checks the credit of the user — whether they’ve paid the entrance fee for a movie theater, or whether they’re permitted to exit school grounds as a student.

A Raspberry Pi is used as the card collector, relaying information on transaction data over WiFi. Meanwhile local identification information via biometric devices and key fobs are relayed to the processor over Bluetooth. There are also plans to develop a mobile app to track the status of the smart gate remotely.

While the full systems integration isn’t published yet, there are several photos of the control box, which shows the components used for the first smart gate. The mechanical design was successfully tested on the IUC Douala Cameroon university campus (with 35-45 students identified per minute), and the project will hopefully be repeated within more schools in the coming year.

Using PoE With A Raspberry Pi 3 For About Two Bucks

September 30, 2019 by Maya Posch 33 Comments

When the Raspberry Pi 3 Model B+ was announced in March of 2018, one of its new features was the ability to be (more easily) powered via Power-over-Ethernet (PoE), with an official PoE HAT for the low price of just twenty-one USA bucks. The thing also almost worked as intended the first time around. But to some people this just isn’t good enough, resulting in [Albert David] putting out a solution he calls “poor man’s PoE” together for about two bucks.

His solution makes it extra cheap by using so-called passive PoE, which injects a voltage onto the conductors of the network cable being used for PoE, without bothering with any kind of handshake. In general this is considered to be a very reliable (albeit non-standard) form of PoE that works great until something goes up in smoke. It’s also ridiculously cheap, with a PoE injector adapter (RJ-45 plug & 2.1×5.5 mm power jack to RJ-45 jack) going for about 80 cents, and a DC-DC buck converter that can handle the input of 12V for about 50 cents.

The rest of the $2 budget is mostly spent on wiring and heatshrink, resulting in a very compact PoE solution that plugs straight into the PoE header on the Raspberry Pi 3 board, with the buck converter outputs going into the ground and +5V pins on the Raspberry Pi’s GPIO header.

A fancier solution would implement any of the standard PoE protocols to do the work of negotiating a suitable voltage. Maybe this could be the high-tech, $5 solution featuring an MCU and a small PCB?

Hypnotic Visuals Synthesizer

September 26, 2019 by Sharon Lin 12 Comments

Ever wanted to make some seriously trippy retro graphics to go along with your lo-fi hip hop beats? Now you can, with [teafella]’s aptly named Hypno Video Synthesizer, a Raspberry Pi-based video synthesizer that digitally emulates and extends analog video workflows through colorization, shape generation, and feedback, patching the modifications into a compact interface. The device allows music creators to perform with live visuals, or alternatively to create a unique visual source for a video setup. Once the CV input is plugged in, all it requires is a composite display and power to start working.

Hypno takes input through a control voltage (CV) jack using a MCP3008 ADC via SPI, with voltages scaled from -5-5V to 0-5V. The device attaches on top of a Raspberry Pi, using Raspbian for the operating system and the Pi Zero GPIO to interface with an OpenGL Engine. The input parameters are taken from knobs through a multiplexer into a single channel of the ADC, with values offset in software based on the CV inputs.

Using the Hypno ends up being fairly straight forward, as the controls are organized onto two mirrored sides for the two oscillators A & B, with global controls in the center. There are knobs that control polarization, rotation, shape, feedback modes (regular, hyper digital, zooming, rotating zoom), clock in/clock out, frequency, root hue, and master gain, as well as RGB LEDs that provide visual feedback.

A single jack outputs the composite result, although a micro-HDMI plug can also be used on the back. For advanced functionality, Hypno allows for patching, which mixes effects on top of one another and allows for shapes such as oscillator cross modulation. There are also alt-controls that open up self modulation and other shapes. Examples include bipolar drift (smoothly scrolls the oscillator) and mirroring (mirrors the oscillator’s shape in different patterns for a kaleidoscope-eque tiled madness).

The software is written in C++ and GLSL, with the main engine running with one plane in OpenGL, drawing the output of a GLSL shader. The CV and knob inputs are fed into shader uniforms that are used to change the visuals in the engine.

[teafella], a self-professed Arduino user, uses WiringPi for the GPIO interactions. The Shader system is inspired by analog video synthesis, with every shape having a simulated “scan” over the screen and function mapped to it that can be transformed into polar coordinates.

The setup for Hypno is fully compatible with analog CV equipment such as Eurorack synthesizers, which makes it easy for music creators to plug and play. Here’s a couple of sample outputs from some soundtracks inputted into Hypno:

Too many combinations to even imagine? Check out a demo of Hypno in action!

Continue reading “Hypnotic Visuals Synthesizer” →

3D Printed VirtuScope Is A Raspberry Pi 4 Cyberdeck With A Purpose

September 20, 2019 by Tom Nardi 23 Comments

William Gibson might have come up with the idea for the cyberdeck in 1984, but it’s only recently that technology like desktop 3D printing and powerful single board computers have enabled hackers and makers to assemble their own functional versions of these classic cyberpunk devices. Often the final product is little more than a cosplay prop, but when [Joe D] (better known on the tubes as [bootdsc]) started designing his VirtuScope, he wanted to create something that was actually practical enough to use. So far, it looks like he’s managed to pull it off.

Many of the cyberdeck builds we see are based around the carcass of a era-appropriate vintage computer, which looks great and really helps sell the whole retro-future vibe. Unfortunately, this can make the projects difficult and expensive to replicate. Plus there’s plenty of people who take offense to gutting a 30+ year old piece of hardware just so you can wear it around your neck at DEF CON.

[bootdsc] deftly avoided this common pitfall by 3D printing the entire enclosure for the VirtuScope, and since he’s shared all of the STLs, he’s even made it so anyone can run off their own copy. The majority of the parts can be done on any FDM printer with a 20 x 20 x 10cm build area, though there are a few detail pieces that need the resolution of an SLA machine.

Under the hood the VirtuScope is using the Raspberry Pi 4, which [bootdsc] says is key to the build’s usability as the latest version of the diminutive Linux SBC finally has enough computational muscle to make it a viable for daily computing. Granted the seven inch LCD might be a tad small for marathon hacking sessions, but you could always plug in an external display when you don’t need to be mobile. For your wireless hacking needs, the VirtuScope features an internal NooElec SDR (with HF upconverter) and a AWUS036AC long-range WiFi adapter; though there’s plenty of room to outfit it with whatever kind of payload you’d find useful while on the go.

Documentation for this project is still in the early stages, but [bootdsc] has already provided more than enough to get you started. He tells us that there are at least two more posts coming that will not only flesh out how he built the VirtuScope, but explain why it’s now become his portable SDR rig of choice. We’re excited to see more details about this build, and hope somebody out there is willing to take on the challenge of building their own variant.

In the past we’ve seen partially 3D printed cyberdecks, and at least one that also went the fully-printed route, but none of them have been quite as accessible as the VirtuScope. By keeping the geometry of the printed parts simple and utilizing commonly available components, [bootdsc] may well have laid the groundwork for hackerdom’s first “mass produced” cyberdeck.

Continue reading “3D Printed VirtuScope Is A Raspberry Pi 4 Cyberdeck With A Purpose” →

WiringPi Library To Be Deprecated

September 18, 2019 by Maya Posch 60 Comments

Since the release of the original Raspberry Pi single board computer, the WiringPi library by [Gordon] has been the easy way to interface with the GPIO and peripherals – such as I2C and SPI – on the Broadcom SoCs which power these platforms. Unfortunately, [Gordon] is now deprecating the library, choosing to move on rather than deal with a community which he no longer recognizes.

Among the points which he lists are the (commercial) abuse of his code, and the increasing amount of emails and messages on social media from folk who either failed to read the friendly manual, or are simply rude and inconsiderate. As [Gordon] puts it, WiringPi was never meant to be statically linked into code, nor to be used with anything other than C and RTB BASIC programmers. He never supported the use of the library with other languages, or having it statically integrated into some Java/JavaScript/NodeJS project.

As this secondary use is what’s draining the fun out of the project, he has decided to put out one final release, before making it a closed-source project, for use by himself and presumably paying clients. What the impact of this will be has to be seen. Perhaps a new fork will become the new ‘WiringPi’?

Suffice it to say, none of this is a good thing. The illegal use of open source code and the support nightmare that gets poured on the authors of said code by less than informed users is enough to drive anyone away from putting their projects out there. Fighting abuse and junking the ‘spam’ is one way to deal with it, but who has the time and energy (and money) for this?

What are your thoughts on this news, and this issue in general? How should an open source developer deal with it?

Thanks to [Dirk-Jan Faber] for sending this one in.

Over-Engineered Cat Door Makes Purrfect Sense

September 16, 2019 by Kristina Panos 21 Comments

On paper, pet doors are pretty great. You don’t have to keep letting the cat in and out, and there should be fewer scratches on the door overall. Unfortunately, your average pet door is indiscriminate, and will let any old creature waltz right in. Well, [Jeremiah] was tired of uninvited critters, so he built a motorized door with a built-in bouncer. Now, only animals with pre-approved BLE tags can get in.

The bouncer is a Raspi 3 running Node-RED, which scans continuously for BLE advertisements from the cats’ collars. [Jeremiah] settled on Tile tags because they’re reliable and cat-proof. The first version used an Arduino and RFID tags for the cats, but they had to get too close to the door to trigger it.

We love [Jeremiah]’s choice of door actuator, a 12V retractable car antenna. [Jeremiah] uses the antenna itself to lift and lower the removable lockout panel that comes with the door. He removed the circuit that retracts the antenna when power is lost, so that power outages don’t become free-for-alls for shelter-seeking animals.

There’s also a nice feature for slow creatures—the door won’t close until 15 seconds after the last BLE ad, so they cats won’t ever have to Indiana Jones it through the opening. Magnetic switches currently limit the door travel at the top and bottom, though [Jeremiah] will eventually replace them with standard switches. Paw at the break until you get a walk-through video.

Cats will be cats, and the ones that go outside will probably rack up a body count. Here’s a cat door that looks for victims clenched between cat jaws and starts a 15-minute lockout period.

Continue reading “Over-Engineered Cat Door Makes Purrfect Sense” →