Hackaday Links: May 18, 2014

May 18, 2014 by Brian Benchoff 9 Comments

Think the original Pong is cool? How about point to point Pong? [v8ltd] did it in three months, soldering all the leads directly to the chip pins. No sockets required. It’s insane, awesome, a masterpiece of craftsmanship, and surprising it works.

[Jeremy Cook] is building a servo-powered light graffiti thing and needed a laser diode. How do you control a laser pointer with a microcontroller? Here’s how. They’re finicky little buggers, but if you get the three-pack from Amazon like [Jeremy] did, you get three chances to get it right.

NFC tags in everything! [Becky] at Adafruit is putting them in everything. Inside 3D printed rings, glued onto rings, and something really clever: glued to your thumbnail with nail polish. Now you can unlock your phone with your thumb instead of your index finger.

Photographs capture still frames, but wouldn’t it be great if a camera could capture moving images? No, we’re not talking about video because this is the Internet where every possible emotion, reaction, and situation can be expressed with an animated GIF. Meet OTTO, the camera that captures animated GIFs! It’s powered by the Raspberry Pi compute module, so that’s interesting.

[Nate] was getting tired of end mills rolling around his bench. That’s a bad thing. He came up with a solution, though: Mill a piece of plywood into a tray to hold end mills.

The Da Vinci printer, a printer that only costs $500 because they’re banking on the Gillette model, has been cracked wide open by resetting the DRM, getting rid of the proprietary host software, and unbricking the device. Now there’s a concerted effort to develop custom firmware for the Da Vinci printer. It’s extraordinarily bare bones right now, but the pins on the microcontroller are mapped, and RepRap firmwares are extremely modular.

A Raspi Ambilight With HDMI Input

May 18, 2014 by Brian Benchoff 19 Comments

With the Raspberry Pi now most famously known as a $30 media PC, it only makes sense that the best uses for the GPIO pins on the Pi are used for an Ambilight. [Great Scott Labs] put up a great video on using the Pi as a uniquely configurable Ambilight with Hyperion and just about any video input imaginable.

This isn’t the first Ambilight clone [Great Scott] has put together, but for the first version the Ambilight functioned only under Raspbian and not any random HDMI input. The new version solves this by using an HDMI splitter box, feeding into an HDMI to composite converter, and finally into a USB composite capture dongle attached to the Raspi.

With the software in the instructions, the Raspi effectively mirrors the video coming from the video capture dongle. The Pi is running Hyperion to control a strip of WS2801 RGB LEDs, making the back of any TV glowey and blinkey.

Since [Great Scott] is using a component video signal as an input, the adapters necessary to have any device work with this Ambilight are readily available. We’d honestly like to see this build working with the old Commodore disk access screen border going nuts, so be sure to send that in if you ever get that working.

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Green Light Go, Red Light Come Back Later

May 14, 2014 by Kristina Panos 19 Comments

Depending on your taste for social interaction and tolerance for distraction, an open floor plan or “bullpen” office might not be so bad with a total of four people. Hackaday.io user [fiddlythings] likes it, but people often stop by to see him or one of his coworkers only to find them busy or absent. While their status is something they could plainly see in Microsoft Communicator from their own desk, some people like to chat in person or stop by on their way to and from meetings.

In order to save these visitors a few seconds, [fiddlythings] came up with an IM status indicator using their existing nameplates outside the door. Each of their names has a little silver dot by it which he backlit with a flattish RGB LED. These LEDs are driven by a Raspberry Pi and NPN transistors through a ribbon cable.

The plan was to imitate the Communicator status colors of green for available, red for busy, and yellow for away. [fiddlythings] dialed up a lovely shade of amber for away using a mix of red and green. Since he really only needs two colors, he’s using eight NPN transistors instead of twelve. The quick ‘n dirty proof of concept version used Python and a Pidgin IM console client called Finch. Once he got IT’s blessing, he implemented the final version in C++ using Libpurple to interface with Communicator.

This isn’t the first time we’ve seen a Pi used to indicate status—remember this mobile hackerspace indicator?

Rackmount RasPi Leaves No Excuse To Lose Data

May 12, 2014 by Rick Osgood 35 Comments

RasPi backup server

[Frank] knows how important backups are for data security, but his old method of plugging a hard drive in to take manual backups every so often is not the most reliable or secure way of backing up data. He realized he was going to need a secure, automated solution. He didn’t need a full-sized computer with a ton of power; why waste electricity for something so simple? His solution was to use a Raspberry Pi as the backup computer.

The main problem he faced with the Pi was finding a way to make it rack mountable. [Frank] started with an empty 1U server case. He then had to bend a few metal plates in order to securely mount the backup drive into the case. A couple of small rubber pads help dampen any vibrations caused by the hard drive.

The computer power supply was able to put out the 12V needed for the hard disk, but not the 5V required to run the Pi. [Frank’s] solution was to use an LM2596 based switching supply to turn the 12V into 5V. He soldered the power supply wires directly to the Pi, thinking that a USB plug might vibrate loose over time. Mounting the Pi to the computer case should have been the trickiest part but [Frank] made it easy by simply gluing the Pi’s plastic case to the inside of the computer case. When all was said in done, the backup server pulls 29W under full load, 9W with the disk spinning, and only about 2W in an idle state.

On the software side of things, [Frank’s] backup box uses bash shell scripts to get the job done. The Pi connects to his main server via VPN and then the bash scripts use rsync to actually collect the files. The system not only saves backups every night, but also keeps week old backups just in case. If you are really paranoid about your backups, try hooking up a custom battery backup solution to your Pi. If a Pi just isn’t doing it for you, you can always try one of many other methods.

Oinker Is Twitter For HAMs

May 12, 2014 by Rick Osgood 57 Comments

Have you ever wanted to send a quick message to your HAM radio buddies over the air but then realized you forgot your radio at home? [Troy] created Oinker to remedy this problem. Oinker is a Perl script that turns emails into audio.

The script monitors an email account for new messages and then uses the Festival text-to-speech engine to transform the text into audio. [Troy] runs Oinker on a Raspberry Pi, with the Pi’s audio output plugged directly into an inexpensive ham radio. The radio is then manually tuned to the desired transmit frequency. Whenever Oinker see’s a new email, that message is converted into speech and then output to the transmitter.

The script automatically appends your HAM radio call sign to the end of every message to ensure you stay within FCC regulations. Now whenever [Troy] runs into some bad traffic on the road, he can send a quick SMS to his email address and warn his HAM radio buddies to stay clear of the area.

BrickPi Bookreader 1 And 2 Read Tablets Or Books Aloud, You Choose

May 10, 2014 by Rich Bremer 10 Comments

BrickPi Bookreader 2

Have you ever wanted to relax with a good book but couldn’t due to the hassle of having to actually read and turn pages? Well, now BrickPi offers 2 solutions to that problem. They have you covered regardless if your document is on a tablet or resides in a physical book.

The original Bookreader will read out loud the displayed text on a tablet. brickpi bookreader This is not an application that runs on the tablet, it is a completely separate device that ‘reads’ the tablet screen. As you could guess from the BrickPi name, the brains behind the operation is a Raspberry Pi. A camera takes a photograph of the displayed text and the Raspberry Pi converts that image file to text using Optical Character Recognition. A Text-to-Speech engine then speaks the text in a robotic sounding voice. In order to change the page the Raspberry Pi controls a Lego Mindstorms arm that swipes across the tablet screen and the entire process is repeated.

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The PebblyPi: A Smart Doorbell

May 8, 2014 by Nick Conn 14 Comments

PebblyPi

A Pebble smart watch, and a Raspberry Pi. They are a perfect match. This is probably what [Daniel] thought when he embarked upon his latest project, a smart doorbell called the PebblyPi (tip submitted by [Ben]).

The actual project is quite easy to implement. All you need really need is a Raspberry Pi, a switch, a resistor, and a Pebble Smart Watch (plus a smart phone). Using a simple Python script on the Raspberry Pi, button press notifications are sent to Pushover, which allows the notification to arrive on your smart phone (and thus your Pebble Smart Watch). Pushover is a very cool notification service for Android devices, iPhones, iPads, and your Desktop. The concept behind this project is great, and the fact that it is so simple to implement opens up many other possibilities for interfacing your home electronics with the Pebble Smart Watch (or even just your smart phone). The ability to create custom notifications on any of your devices using any internet connected system is amazing!

You could receive notifications from your absurdly accurate weather station, or even your soil moisture monitor. Have you used Pushover in any of your projects? The possibilities are endless!

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