What You Can Do When A Raspberry Pi Teams Up With An Arduino

August 31, 2012 by Mike Szczys 16 Comments

We thought that connecting an Arduino to a Raspberry Pi was overkill, but one thing caught our attention. [Jan Stevens] mentions that the RPi is less expensive than the Ethernet Shield. Interesting. As we looked into his writeup a bit more we began to think he’s onto something. [Jan] uses the PHP serial class to communicate between the RPi and Arduino (dead link; Internet Archive). This ends up being a very inexpensive way to bring some of the more powerful web programming options to your hardware devices.

Sure, he’s just driving three RGB LEDs. But the demo video after the break gives us a glimpse as some of the interface options that become available when an embedded Linux machine is in play. He’s using jQuery, AJAX, PHP, and JSON to name a few. If you want to give this a try yourself you can grab the code from his Github repo. Of course we’re going to want to hear about any projects you develop from this starting point!

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Party Photo Printer Built Around A Raspberry Pi

August 29, 2012 by Mike Szczys 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.

Building A PBX Setup Around The Raspberry Pi

August 22, 2012 by Mike Szczys 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 A PIC Programmer

August 17, 2012 by Mike Szczys 19 Comments

[Giorgio Vazzana] turned his Raspberry Pi into a PIC programmer using a rather small collection of common parts. It supports about a dozen different chips from the 16F family. But we’d guess that software is the limiting factor when it comes to supporting more chips.

Generally the problem with PIC programming is the need for a 12V supply. He chose to use an external 12V supply and a 78L05 linear regulator to derive the 5V rails from it. With the power worked out there are some level conversion issues to account for. The RPi provides 3.3V on the GPIO header pins, but 5V logic levels are needed for programming. He built transistor and voltage divider circuits to act as level converters. The programming software bit bangs the pins with a write time of less than eight seconds per 1k words of program data. So far this does not work with ICSP, but he plans to add that feature in a future version.

Raspberry Pi Wedded To A DSLR

August 16, 2012 by Mike Szczys 11 Comments

This is a Raspberry Pi outfitted in a DSLR battery grip. [Dave H] was very interested in the idea of combining a single-board computer with a high-end camera. The size and cost of such a computer was prohibitive until the RPi came along. He managed to fit the board into the broken battery grip he had on hand, and he already has the prototype up and running.

[Dave’s] alterations to the battery grip allow access to the USB, Ethernet, and Composite video ports. Powering the RPi was a bit of a challenge. He tried using an iPhone charger with four AA batteries but that only provided 4.2V. After going back to the drawing board he discovered he could rework the parts that he removed from the grip, using a Cannon 7.2V 1800 mAh battery. So far he can automatically pull images from the Camera and transmit them over a network connection. But since the RPi is running Linux, there’s a whole world of hacks just waiting to be exploited. What comes to mind first is image manipulation software (like ImageMagick) which has a command-line interface.

[Thanks Christian]

Android 4.0 On Raspberry Pi

August 1, 2012 by Mike Szczys 29 Comments

The folks over at the Raspberry Pi foundation are showing off their latest wares. This time around it’s Android 4.0 running on the Raspberry Pi. Although this is a pre-release announcement, it sounds like the work is rather far along. Hardware acceleration for video playback is in place, but there are still some audio issues that need to be fixed before it will be ready.

We know the foundation isn’t the first one to pull this kind of thing off. Look around and you can see some other proof-of-concept videos which show Ice Cream Sandwich running on the board in one stage or another. But the demo from the video after the break gives us hope that rock solid support is just around the corner. After all, Netflix runs on Android and so does XBMC. Both running on the RPi brings the device one step closer to the holy grail of dirt cheap and mostly-open set top boxes. The one thing we haven’t seen yet is the killer control method for the device. If you’ve got one up your sleeve you should post some details and send us the link.

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Gaining Low-level SPI Access On The Raspberry Pi

July 27, 2012 by Mike Szczys 7 Comments

Raspberry Pi - rpi

We’ve seen a ton of projects that interface hardware with the Raspberry Pi. But they usually depend on bit-banging. That means they toggle the pins in software to match a specific protocol. The thing is that the beefy Broadcom SoC that anchors the board has a lot of built-in peripherals that are just waiting to be used instead of bit banging. In this case, it’s the hardware SPI peripheral which can be accessed via the bcm2835 library for RPi.

One of the things that would have really complicated this process is the pin mapping between the Broadcom chip and the RPi GPIO header. Since not all pins are broken out, it was either luck or good design forethought that made all of the SPI0 pins from the chip available on the RPi breakout header. The library page (linked above) explains this well. But if you’re looking for more of a working example check out [EngineerByNight’s] project with adds an accelerometer using hardware SPI.