Raspberry Pi: 10 fun and fantastic mods

Magic mirror

This 'magic' mirror won't tell you who's the fairest, but it could pay you a compliment and let you know whether a brolly is a must before venturing out.

Thanks to its digital makeover the mirror can show news reports, provide weather updates or just display the time and date.

Plumbing an object thousands of years old into the internet required Michael Teeuw to carry out some nifty hardware and software hacking.

The mirror itself is semi-transparent, an observation mirror that allows people to look through when it is lit from behind.

Information is shown on a display panel from a 24-inch monitor that has had its plastic casing removed and is placed behind the mirror.

Teeuw then built a new pine wood casing for the mirror and the display panel and wired together the panel, a Raspberry Pi, USB adapter and wi-fi adapter.

After installing wi-fi connectivity, Teeuw customised the Raspbian OS's display to portrait orientation, and to boot directly into the mirror's interface.

The interface for the mirror was built using JavaScript, HTML and CSS and served by a local Apache web server to the Chromium browser, which Teeuw configured to run in full screen mode when the Pi booted.

Data for the weather, news and calendar interface on the mirror was pulled from various APIs of online services: Openweathermap.org, the NOS News Feed and Apple's iCloud.

The materials used in the project can be found here and the code used to build the interface is available on GitHub if you fancy adding new features.

Image: Michael Teuuw

Jasper

If you're looking for a voice-controlled virtual assistant and Google Now and Apple's Siri don't cut it then Jasper might be just the machine you're looking for.

Jasper is an open-source platform for voice-controlled computing that, with a bit of programming know how, can be trained to tell you what you want to hear.

In demos the creators of Jasper show it telling the time, reading weather forecasts and Facebook notifications and playing a track from Spotify.

If none of these take your fancy it's possible to add new abilities to Jasper using the programming language Python to access Jasper's API. By building new modules developers can train Jasper to answer new questions and hook up new online data sources.

By default Jasper's software stack includes modules to check the time, news, weather, Gmail and more.

Hardware wise Jasper requires nothing more than a Raspberry Pi, USB adapter and microphone.

After installing the default Jasper client on the Pi, users will need to spend some time setting it up and connecting it with online accounts, such as Gmail and Spotify.

Jasper utilises a number of open source libraries, including Pocketsphinx for speech recognition, the eSpeak text-to-speech program for its voice and Phonetisaurus and CMUCLMTK to generate dictionaries and language models on the fly.

Image: Shubhro Saha / YouTube

Sous-vide cooking

Sous-vide cooking is back in vogue and for good reason, with its ability to turn a rough cut like brisket into a succulent delight.

The technique requires some pretty pricey equipment, but by pairing the Pi with some electronic sensors you can be sous-vide cooking for tens, rather than hundreds or thousands of dollars.

Sous-vide is the practice of poaching food sealed inside an air-tight bag, where the water is kept at a precisely-controlled temperature. The approach ensures foods are evenly cooked and that meats keep their moisture and fish an al-dente texture.

In this mod a crock pot - an electrical slow cooker - connected to a Raspberry Pi is used to poach the food sous-vide style. The Pi regulates the power sent to the pot, and hence the temperature it is cooking at, depending on the temperature of the food and the water. This feedback loop cooks the food at a consistent temperature.

The system requires a 5V 2-relay control module to control the power to the crock pot, two food temperature probes - to measure the temperature of the food and the water and a MCP3008 analog-to-digital converter to allow the Pi to get the temperature readings.

Setting up the system requires some manual wiring and coding using the Wolfram Language and a guide to how to set it up can be found here.

Image: Wikimedia Commons / Arnold Gatilao

Project Mudra

Mudra is a Raspberry Pi-based device that automates the teaching of Braille.

The device was designed by Sanskriti Dawle and Aman Srivastav, who are 20-year-old second-year students at the Birla Institute of Technology and Science in Goa. The pair wanted to improve Braille literacy, which reportedly remains low worldwide and is especially scarce in India.

"If you are visually impaired Braille is your passport to literacy," said Dawle in a brief demo of the project online.

The device offers different modes for learning and is designed to help people learn Braille at their own pace.

Auto mode translates the English alphabet into Braille letter by letter. The user listens to each letter being spoken while placing their hand on a block of six pins that arrange themselves into the corresponding Braille symbol. The pins are controlled by the Raspberry Pi. Meanwhile browse mode uses Google's speech to text API to convert words spoken by the user into Braille.

The pair demonstrated Mudra at last month's PyCon event in Montreal.

Here is the Mudra repository on GitHub.

Image: Project Mudra

3D scanner

This contraption might look like a prop from a Sixties sci-fi show but is instead a 3D scanner for people.

Since its creation the rig has captured hundreds of people in digital form, designs that have been used to produce tiny plastic dolls using 3D printers.

Building the scanner was no small undertaking, requiring some 40 Raspberry Pis and camera modules, 40 8GB SD cards, one single 60A 5v power supply to power the Pis, as well as LED strips and a 12v power supply.

Cameras and Raspberry Pis are mounted along each curved rib and the person sits at the centre of the set-up with 36 cameras pointing at them. When a wireless signal is received all 36 cameras capture an image of the person sat at the centre.

The images captured by the cameras are uploaded to a different machine for processing and used to build a digital 3D model, with the creator testing out a range of software and services: including Autodesk 123D Catch, Autodesk Recap Photo, VisualSFM and Agisoft Photoscan Standard.

Image: The Pi 3D Scanner Project

Video billboard with a twist

Video billboards are nothing new, but adverts that blur the line between reality and digital life are certainly novel.

These billboards at an underground station in Sweden were fitted with Raspberry Pis attached to ultrasonic sensors that monitored when a train pulled into the station.

When the train arrived the Pi triggered a video of the female model's hair waving madly, as if blown by air displaced by the train.

The advertising agency behind the screen is Åkestam Holst from Sweden, working with production company Stopp for Apotek Hjärtat's Apolosophy products.

Stopp says the ad was scheduled to be run for just one day, but was so popular the company which owns the screens asked for it to run for the rest of the week.

Image: STOPP/CONTENT/APOTEK HJÄRTAT - APOLOSOPHY

PiPhone

The PiPhone doesn't sports hundreds of apps, in fact it does just one thing, makes phone calls.

But that doesn't make the phone - made by connecting a Pi to a small Adafruit TFT touchscreen, Sim900 GSM/GPRS module and a battery - any less impressive.

Cobbled together for just $158, it's one hot product, as there's no heat sink on the CPU, and creator Dave Hunt warns the phone tends to get "a bit warm" if left switched on for several minutes.

All the code for the system and instructions on how to build it are available from its repository on GitHub.

Image: Dave Hunt

Raspberry Pi cluster

Raspberry Pi clusters are a dime a dozen, but this Pi "supercomputer" shows you don't need a server farm to test distributed software.

The 40-node cluster is packed into a case no larger than a full-tower desktop and costs about $3,000.

Storage is provided by an array of five 1TB drives, expandable to 12TB, and there is 440GB of flash storage. The system shares 20GB of distributed RAM, while networking is served by internal 10/100 network connections for individual nodes, and externally by four 10/100 LAN and one router uplink.

"In the practical sense, this is a supercomputer which has been scaled down to the point where the entire system is about as fast as a nice desktop system," wrote creator David Guill.

"Most of the resources available to individual nodes have been proportionally scaled. I believe this will make it an ideal testbed for distributed software."

Now the system is complete the creator plans to install a variety of software packages for distributed computing that run on top of Apache Mesos, giving the example of MPI and Hadoop.

"In the future, I will be writing my own distributed applications, which may include my own cluster management software and some form of reality simulation engine."

Image: LikeMagicAppears

Wearable display

If you find Google Glass too obnoxious then how about some Pi in your eye?

This wearable display is designed to clip onto glasses so the Pi can be used on the move.

The Pi-powered glasses are made by removing the composite display from these $100 video glasses and placing it inside a plastic enclosure, which can be made using a 3D printer and the following schematics.

Building the glasses requires some light soldering and electronic tinkering, as well as editing a config.txt file to get the display working properly.

To use the Pi on the move you'll also need to pick up a USB battery pack, and a miniature wireless USB keyboard with touchpad.

A full explanation of how to make the wearable display can be found at the Adafruit website.

Image: Adafruit Industries / YouTube