Raspberry Pi

1934 Articles

Raspberry Pi Synth Gives A Softsynth Dedicated Hardware

August 31, 2012 by 6 Comments

For all the musicians out there, here’s a great use for your Raspberry Pi. All the features you would expect from a nice analog synth are implemented in a Raspberry Pi-based polysynth – dual oscillators, LFOs, and phasers – and it looks like there will be a few more features added before the Raspi synth is released.

Even though the ‘synthesis’ part of the Raspi synth already sounds wonderful, getting MIDI on the Rasberry Pi leaves much to be desired. The creator of the Raspi synth thought about using the GPIO pins as a MIDI interface, but because the GPIO pins cannot run natively at 31250 bps (the MIDI spec), the Raspberry Pi has to waste most of its CPU cycles just listening for MIDI traffic.

Right now the Raspberry Pi synth is controlled by a USB-connected MIDI interface, and as you can hear after the break, sounds wonderful. We can’t wait to hear what this synth will be able to do in a few months’ time.

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Party Photo Printer Built Around A Raspberry Pi

August 29, 2012 by 12 Comments

We think [Brian Delacruz] latched on to a good idea with this photo printer project. Instead of building a big photo booth for his party he developed a Raspberry Pi based WiFi photo printer. Right now it’s a prototype that lacks the kind of polish necessary to make a true user-friendly device. But the idea is solid and just waiting for you to improve upon it.

In addition to the RPi he’s using a quality photo printer and a small wireless router. The router simply provides WiFi capabilities for the RPi which is running a web server, mySQL, and FTP. This provides a wide range of upload options which he can work with. Watch the video after the break to see him print a smart phone photo wirelessly.

This can be simplified by using a package like hostapd to use a USB WiFi dongle as an access point. Or if the venue already has Internet access a server could be set up with a QR code to guide people to it. The party starts off with an empty bulletin board and guests would be invited to print and hang their own photos which will go into the host’s guest book/scrap book to remember the event.

The Dark Pi Rises

August 25, 2012 by 22 Comments

Ever wonder how an aerospace engineer would build a telepresence rover? Well, if [algorythmic] can be used as our reference, he’d cram a Raspberry Pi AND an Arduino into an RC truck frame.  The arduino is being used for motor control while the Raspberry pi is doing the communicating back and forth to the base. He’s using a ps3 controller as his interface and has slightly modified his PS3 eye for better night viewing.

Before you start shouting that using the raspberry pi AND the arduino is massive overkill, let us remind you that people don’t necessarily go buy/build all the parts for each project with a long-term goal in mind. He could have had both sitting there and realized that he didn’t need to add parts to either of them.

With the Raspberry Pi at the helm, this opens up all kinds of possibilities for adding features to make this an autonomous vehicle. Looking around his blog a little bit, it seems he’s done some visual recognition as well as voice control in the past. This could be interesting!

 

Control Raspi GPIO Pins In The Browser

August 22, 2012 by 30 Comments

Now instead of wrangling Python or PHP to do your bidding, [Eric] came up with a way to control the GPIO pins on his Raspberry Pi in a browser.

[Eric] calls his project WebIOPi, and it’s the perfect tool if you’d just like to blink a LED or control a relay over the internet. Simply by pointing his browser to the IP of his Raspi, [Eric] can turn GPIO pins on and off, directly from his desktop browser.

All the code for WebIOPi is available on [Eric]’s Google code page. The UI of [Eric]’s project is fully customizable, so it’s entirely possible to control your garage door from a smart phone simply by loading up a web page hosted on your Raspi and pressing a button.

Right now WebIOPi is only able to turn GPIO pins on and off. That will change as [Eric] implements UART, SPI, and I2C in his project, making it possible to do a lot of cool stuff without having to write much – if any – code.

Building A PBX Setup Around The Raspberry Pi

August 22, 2012 by 47 Comments

We’re not sure why this use didn’t immediately come to mind when we got our hands on a Raspberry Pi board, but the hardware is almost perfect as a PBX system. PBX, or Private Branch Exchange, is basically an in-house phone system. This guide which [Ward] put together shows you how to do some interesting things with it.

When talking about PBX setups the most common software package is Asterisk. That’s what’s at work here, rolled up with a bunch of other helpful software in an RPi targeted distro called Incredible PBX. All it takes to get up and running is to partition and burn the image to an SD like any other RPi distro. The configuration ends up being most of the work, starting with changing the default password, and moving on to customizing the environment to match your phone numbers and your needs. As with PBX setups on other embedded Linux devices, Google Voice is your best friend. The service will set you up with a free phone number.

This guide doesn’t delve into hardware connected hand sets. You’ll need to use a SIP phone. But that’s easy enough as there are free apps for most smart phones that will do the trick.

[Thanks Jamie]

Raspberry Pi As An AVR Programmer

August 20, 2012 by 23 Comments

AVR programmers can be bought for just a few dollars on the Internet, but if you’re building an expansion board with an AVR for your Raspi, this is the build for you. It’s a safe way of programming an AVR via the Raspi’s GPIO pins that uses an extremely minimal circuit.

The AVR ISP interface looks a lot like an SPI interface, and the easiest way to program an AVR with a Raspi would be to bitbang all the commands from the GPIO pins. Sometimes, though, the logic of the AVR and Raspi would be at different levels, so while bitbanging may work in a pinch it’s not something anyone should use regularly.

To get the Raspi and AVR talking to each other safely, [Steve] built a small circuit from a 74244 buffer and a FET. With the added support for Linux GPIO avrdude programming, it’s a snap to program an AVR with a Raspi.

A few days ago we ran across a hugely overwrought PIC programmer for the Raspi, so we’re glad to see another round in the PIC/AVR holy war go to the AVR camp.

Thanks [Mateusz] for sending this one in.

An Adafruit Raspberry Pi Extravaganza

August 18, 2012 by 4 Comments

The folks at Adafruit are busy as a bee working on bringing some of their really cool boards to the Raspberry Pi platform. Here’s a few that came in over the last few days:

16 servos is almost too many

Servos require a PWM output but the Raspi only has hardware support for PWM on a single GPIO pin; certainly not enough to build a gigantic, city-leveling robot. [Kevin] over at Adafruit put together a tutorial for using this 16 channel servo driver with the Raspi.

12 bit DAC

With only one PWM pin and no analog out, it was only a matter of time before someone hooked up the Adafruit 12 bit DAC to the Raspberry Pi.

16×2 LCD displays

Both the servo and DAC builds use the Adafruit I2C library and a bit of Python. Of course it’s possible to treat the GPIO pins on the Raspberry Pi as digital outs, just as [Mikey] did with his Raspi LCD display tutorial.

So, what distro are you using?

Of course all these builds use Adafruit’s Occidentalis distro, a maker-friendly Linux distro we’ve posted about before. It’s too useful to languish as a single Hackaday post, so here it is again.