The RPC: A Stand-alone MIDI Workstation

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

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

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.

Raspberry Pi Bitcoin Miner

Mining bitcoins is becoming a fool’s errand, but there’s always some new piece of hardware coming out that allows those hard-core miners to keep ahead of the curve. One such piece of hardware are new custom ASIC devices that are just as fast as an FPGA while being much less expensive. A lot of these ASIC devices come in interesting packages that look just like a large USB thumb drive. Of course this is the perfect opportunity to show off what the Raspberry Pi can do by mining Bitcoins at rates comparable to the best graphics used in mining today.

The Raspberry Pi simply doesn’t have enough horsepower to mine bitcoins at any worthwhile rate. There are, however, USB ASIC devices that will mine for you at about the same speed as a high-end graphics card. Since multiple ASIC devices can be controlled through a USB hub, it’s simply a matter of plugging a USB hub into a Raspberry Pi, loading up CGminer, and letting your new PiMiner loose on a mining pool.

The Adafruit Pi Miner uses one of their really cool LCD character displays and keypad to display the current mining rate, accepted shares, and enough information for you to calculate how long it will take to break even with your Pi powered mining rig. How long that will be for this four device rig we’ll leave to the comments section.

R2D2 Cake Plays Leia’s Distress Message

As all 6-year-olds should, [Marc]’s son is a huge fan of Star Wars. For his birthday party, he wanted a Star Wars themed cake, and making one in the shape of R2D2 seemed to be right up [Marc]’s alley. Of course any clone of everyone’s favorite R2 unit should also display Leia’s distress message to Ben Kenobi, and [Marc] figured out a way to do just that.

Because of R2’s strange and decidedly non-cake shape, [Marc] first constructed a stand out of wood, cardboard, and a PVC pipe to hold the cake into place. The cylindrical droid body is of course made of cake and frosting, with R2’s dome made out of fondant.

The PVC pipe running up the center of the droid provided [Marc] with the ability to run a power and video connector up R2’s spine. These are connected to a small projector receiving video from a netbook placed out of the way.

You can check out a video of the R2 cake playing Leia’s holographic distress message below. At the end of the video, there’s a 6-year-old birthday party guest saying, “what is that?” It might be time to dig out the VHS player and the non-remastered trilogy, [Marc].

Learning Letters, Particularly R, F, I, & D

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After [yohanes] picked up a toy at a yard sale – a Leap Frog Letter Factory Phonics – he thought he could do better. The toy originally asked a child to find a letter, and after digging one of 26 plastic characters out of a plastic tub and placing them on the Letter Factory’s sensor, would play a short musical ditty. [yohanes]’ version does the same, but because he made it himself it is infinitely more expandable.

The letters for [yohanes]’ version are RFID tagged. This, combined with a cheap RFID module and a bluetooth module means a Raspberry Pi can read RFID cards from across the room. From there, it’s a simple matter of writing up some Python to ask his toddler for a letter, reading the bits coming from a bluetooth, and keeping score.

The build isn’t over by a long shot. [yohanes] still needs to make his build multilingual by adding Indonesian and Thai. There’s also a possibility of adding a spelling game to make it more interesting.