raspberry pi

1709 Articles

Put In Pocket Change, Get Bitcoins

August 22, 2013 by 40 Comments

bitcoin

[gbg] put together a neat little project to get people familiarized with Bitcoins. A lot of techies know what Bitcoins are, but the impetus to download the Bitcoin client and start mining is a bit too much for some. [gbg] has a solution for this – a Bitcoin vending machine. Just dump your pocket change in the coin slot, and out comes a QR code that allows you to add Bitcoins to your wallet.

Inside this Bitcoin briefcase is a Raspberry Pi that connects to a local WiFi connection. Every five seconds, the Raspi looks at the current conversion rate of USD to Bitcoins. Once coins are deposited into the briefcase, a receipt complete with a scannable QR code is printed on a small thermal printer.

When [gbg] took this to the latest DEFCON, a lot of people were interested in the project and started shoveling change into the machine. So many people were interested that [gbg] and his compatriots are planning on turning this into a proper open-source device, complete with a bill reader and possibly an ASIC miner so the Pi can sell the coins it produces.

Check out the video below for some more info.

Continue reading “Put In Pocket Change, Get Bitcoins” →

Building An Entire Pinball Machine From Just The Playfield

August 19, 2013 by 9 Comments

It all started  when [Iancole] bought a Fireball Home edition playfield on some famous auction website for $135. Originally, he had the intent of lighting the lamps with an Arduino, framing it, and hanging it on the wall of his office — which often happens with old pinball parts. But then his boys asked if he “could make it play”.

[Iancole] managed to find the pinball schematics online and started designing the electronics required by the many LEDs, solenoids and switches. As the LEDs and switches are on the same matrix, he chose a simple Arduino to cycle through them, giving the player the impression that the lights are constantly on. [Iancole] originally planned on using his raspberry Pi to control the solenoids, but he later switched to another Arduino because of the precise timing required.

Therefore, his Pi was used as the heart of the machine. It is interfaced to the two Arduinos to read states and send commands while running the game program, displaying HD graphics on a 24″ screen, playing music and game event sounds. All the electronics are proudly displayed on the backbox, and many developments are planned for it. Also, the machine will be on display at the Orlando Mini Maker Faire on October 5th!

Turning A Tiny Linux Box Into A Synthesizer

August 16, 2013 by 9 Comments

waveforms

For all the cool things the Raspberry Pi, BeagleBone, and other low-power Linux boards can do, there’s one thing we haven’t seen much of: creating music with software synthesizers. Yes, soft synths have been around for ages now, but compiling them for these ARM boards is something we haven’t seen much of (to say nothing of the Linux audio system). Luckily, [Paul] and [Trev] have put together a tutorial for making synthesizers on these small Linux boards using Csound, the premier audio programming language for Linux.

[Paul] and [Trev] have already put together a few Csound instruments that include a Vangelis-inspired synth, a Lorenz Strange Attractor FM synth, a drum machine, and a classic monophonic style synth. All these instruments are ready to play on a Raspi or BeagleBone and we’re sure we’ll see a few more applications of this great tool for creating musical instruments as more musicians are turned onto these small Linux boards.

The RPC: A Stand-alone MIDI Workstation

August 14, 2013 by 11 Comments

raspiMidiRPC

Not just another pretty enclosure, this shiny little red box is [Lauri’s] stand-alone MIDI workstation. The build uses an Arduino Mega 2560 to handle the MIDI inputs and outputs. It communicates via serial with a Raspberry Pi that acts as a sequencer and oversees all user interactions. The Pi’s SD card offers convenient storage for your work, though we wish it was easily ejectable from the front of the box and not trapped under the hood. [Lauri’s] RPC also squeezes in the necessary USB hub for the RasPi and an HDMI-to-VGA converter. As an all-in-one solution, this is a sleek little box that–once paired with some software for arpeggiators, chord harmonies, and scales–will be a handy MIDI sequencer with robust control ready to be conveniently mounted on your rack.

Now all you’ll need is something to plug in. Why not check out the custom MIDI recorder we featured last week, or the organ-to-MIDI keyboard conversion for inspiration.

[Thanks Teemu]

Raspi Bitcoin Miner May Just Pay For Itself Eventually

August 13, 2013 by 32 Comments

We’re sure a lot of people out there have a Raspberry Pi or two lying around waiting for a project to come to mind.  [Dave] has an interesting solution to this orphaned hardware – use it to mine Bitcoins and perhaps put a few extra bucks in your pocket at the end of the year.

[Dave] is using a Raspberry Pi, powered USB hub, and an ASICMiner Block Erupter to do Bitcoin mining at 330 Megahashes per second. There are a few ancillary items such as a case and USB fan, but if you already have a Raspberry Pi, you’re only looking at a $50 USD investment to have a dedicated Bitcoin miner.

According to this Bitcoin mining profitability calculator, with a $50 investment that can mine at 330 MH/s, you’re looking at a hardware break even point of about 120 days. You could cut that down to just a few months if you overclock your ASICMiner, but it’s still relatively late in the game for amateur Bitcoin miners to make a substantial amount of money. Think of Bitcoin mining as more of hobby, and you’ll hopefully be more realistic about your goals.

Raspberry Pi, Now In A Mini-ITX Form Factor

July 2, 2013 by 35 Comments

Shown above is a fairly simple Raspberry Pi setup. There’s the Raspi itself, a 2.5″ hard drive, a USB hub, GPIO expansion, and wireless and Bluetooth adapters. Throw in the power supplies for all these devices, and you’ve got a real mess on your hands. There is a solution to this problem of a Gordian knot of USB and power cables: the Fairywren, a board that turns your Raspberry Pi into a Mini-ITX computer.

The basic idea behind the Fairywren is to take the basic outline of a Mini-ITX motherboard and add goodies like a real-time clock serial port, and USB hub while providing a secure mounting place for a Raspberry Pi. It turns a Raspberry Pi into a proper computer, with all the ports in the rear, and is compatible with a whole slew of Mini-ITX cases.

At £40, the Fairywren isn’t exactly cheap. In fact, it’s more expensive than the Raspberry Pi itself. That being said, you do get a whole lot of hardware for the price, and if you already have a small Mini-ITX case lying around, it may be just the thing to clean up the mess on your electronics bench.