Category: hardware

Links: How to extend the life of the SD card on a Raspberry Pi (or similar device)

People are using the Raspberry Pi for many applications these days, including as a VoIP PBX server based on Asterisk. One thing that many people forget is that you can only write to an SD card a limited number of times before it fails. Asterisk in particular likes to write a LOT of information to log files, and let’s face it, if you are honest and you are like 99% of Asterisk system administrators, you will admit you never read them unless perhaps you suspect there is a problem with your system. Yet every one of those many writes reduces your SD card’s lifespan by a small amount.

So with that in mind, here are links to a few threads that may or may not be helpful, in no particular order:

How can I extend the life of my SD card? (Raspberry Pi Stack Exchange)
How can I use a USB HDD to extend the life of my SD Card? (Raspberry Pi Stack Exchange)
Read/Write cycles of a SD card (RaspberryPi.org)
Extending the life of the SD card (RasPBX – Asterisk for Raspberry Pi/Sourceforge)
How to add ‘noatime’ to fstab? (AYK solutions)

Know of any other good links on the subject? Please leave a comment!

Cubieboard2 open single board computer ships, Cubietruck model revealed

This comes to us from LinuxGizmos:

The forthcoming Cubietruck will have additional I/O ports
The forthcoming Cubietruck will have additional I/O ports

The Cubieboard open SBC project began shipping a faster Cubieboard2 version of its open source Linux and Android SBC, and revealed prototypes of a new, larger, enhanced Cubietruck model. Like the $59 Cubiboard2, the Cubietruck uses an Allwinner A20 dual-core Cortex-A7 SoC instead of the original’s single-core Allwinner A10, and adds a 2GB RAM option, WiFi, Bluetooth, gigabit Ethernet, VGA, and SPDIF ports.

Read the full article here.

Note that the abbreviation “SBC” in the above-linked article stands for “single board computer”. In our opinion, if the Cubietruck works reliably it could relegate the BeagleBoard Black to also-ran status, and could even give the Raspberry Pi a run for its money among those who’d like just a bit more power and a wider selection of outputs. For Home Theater PC builders, the inclusion of a SPDIF Toslink optical port is no small thing. We’ll definitely be keeping an eye on this one!

How To Use The Raspberry Pi As A Wireless Access Point/Router, and other Raspberry Pi tricks

Just some quick links for the Raspberry Pi fans out there, from a multi-part series of articles on “How To : Use The Raspberry Pi As A Wireless Access Point/Router” via a blog called The Rantings and Ravings of a Madman:

Part 1 — How to create a Wireless Network On Your RPi
Part 2 — How to make your RPi into a Wireless Access Point
Part 3 — How to make your RPi into a Router
Part 3B – Issues with HostAPD ? Click here!

But the author of this blog didn’t stop there. Here are a few of his more recent articles, in a similar vein:

Script : WiFi Checker Script
Script : Starting hostapd when WiFi goes down
How To : Turn the Raspberry Pi Into a Shaping WiFi Router
Script : Web Configuration Page for Raspberry Pi
RaspAP WebGUI
How To : Use A RT5370 USB WiFi NIC In A Bridge

And in case you are thinking that the only things he knows how to do with a Raspberry Pi involve WiFi, guess again! Here is a link to all his Raspberry Pi related posts.

If you have an RSS newsreader, you might want to add his feed, or follow him on Twitter to get notifications of his latest blog posts.

If you know of any other great blogs for Raspberry Pi users that are of the same caliber as this one, please feel free to let us know in the comments!

Link: Build Your Own Raspberry Pi Case from Cardboard or Cardstock

From a company that sells Raspberry Pi’s in North America comes this:

One of our top selling accessories for the Raspberry Pi is the case. Cases for the Pi come in a multitude of styles, sizes and colors, but if you’re like us, you’re the type of person who loves to build it yourself. Today we’re going to build a bare-bones case out of cardboard with supplies you may already have laying around the house.

Read the rest of the article here:
Build Your Own Raspberry Pi Case from Cardboard or Cardstock (MCM Electronics)

In case you are wondering, the finished enclosure looks something like like this (depending on what you make it out of). Just be sure to use a non-conductive material:

An alternative way to power a Raspberry Pi

Did you know that you can use a $20 USB hub (but not just any old USB hub) to power a Raspberry Pi AND use the SAME hub to add additional USB ports to the Pi? Well, you can, as demonstrated in this video:

 

Direct YouTube Link

Apparently not all USB hubs will work, because many only put out something close to the 500 mA that is the specification for USB 2.0, whereas the Raspberry Pi Model B requires 700 mA. So, the hub has to put out a bit of extra current or it won’t power the Raspberry Pi properly.

There is a list of USB hubs that will work with the Raspberry Pi, but pay special attention to the comments in the rightmost column. Only a few of the USB hubs shown are known to be able to power the Raspberry Pi reliably. The one shown in the video is the Plugable 7 Port High Speed USB Hub, model USB2-HUB-AG7 (Amazon affiliate link – we make a small commission if you click on it and purchase a unit).

EDIT: A few weeks after we originally posted this article, the device described in the following article was released:

PiHub from Cyntech and Pimoroni – a new powered USB Hub for the Raspberry Pi

Unless you really don’t need that many USB ports, and you absolutely fall in love with the Raspberry-shaped case of the PiHub, we suggest you stick with the Plugable 7 Port hub mentioned above. Not only are you getting more USB ports, and a hefty 3 Amp power supply, but if you’re in the U.S.A. or Canada it’s actually available here and has mostly 4 and 5 star reviews on Amazon. And if you go with the PiHub, by the time you do the currency conversion (and let your credit card company take a small bite on the exchange rate), and pay for the shipping, you’ll be paying more and getting less (only four ports rather than the seven offered in the Plugable unit). But, you will be getting that lovely Raspberry-shaped case, so there’s that.

Video: Turning the Raspberry Pi into an FM transmitter with PiFM

Direct link to YouTube video

Link to page that describes how it’s done: Turning the Raspberry Pi Into an FM Transmitter

The interesting thing about this: Other than the Raspberry Pi and its power supply, the only external hardware required is a piece of wire to act as an antenna, and a way to connect it to the correct pin on the device!

Some people are gluttons for Pi: Mounting multiple Raspberry Pi devices

Some fans of the Raspberry Pi just can’t get enough, it seems, and have devised various ways to mount multiple Pis. In fact, when this idea occurred to us, we thought we had the perfect name for such a device – the Pi Rack – until we found out that name was taken by hydroponic growing systems that are sometimes used to grow medical marijuana, and other types of plants. So, guess that idea was only half-baked.

(We’ll pause a moment while you groan at that bad pun, realizing it works two ways. You know, baked pi(e), and baked from… do we really need to spell it out?)

Anyway, we came across this clever way to mount multiple Raspberry Pis, using a block of plywood and the audio and video jacks as mounts:

DSC04761

For more photos, and details on construction and the components used, see this article and the comments underneath:
Simple Pi Rack (raspberrypi.org)

(2020 Edit:) If you happen to stumble across this old article, note there have been several newer ways to mount multiple Pi’s developed since it was written. Some are homemade and some commercial. Some require a 3D printer, such as this one:

3D Printed Raspberry Pi Server Serves Up Fourteen Slices of Pi (Tom’s Hardware)

Do-it-yourselfers: Raspberry Pi with Asterisk installed to act as a door entry system

This is for those that are really into building their own hardware, in addition to being familiar with Asterisk. From Reddit’s Asterisk section comes this post:

I’m working on using a Raspberry Pi with Asterisk installed on it to act as a door entry system integrated with my home phone system (also running Asterisk). The operation I would like is this:

    Doorbell pushed.
    Raspberry Pi detects push and its asterisk originates a call from the local console channel to some predefined extension on the main asterisk server, which routes to the appropriate house extensions.
    Person at door hears either ringing or music, whatever.
    Call is eventually answered.
    Caller talks to owner and owner decides to let caller in.
    ????
    Asterisk in Raspberry Pi activates a local GPIO pin to open the door strike.

I believe I’ve got all of the above described parts working, or at least workable. The “????” line — I haven’t.

The post continues to explain the thinking that has bee put into solving this problem. Then others chime in, and finally a solution is found that involves some lines added to Asterisk’s features.conf file, and a small program in C. We’re not into hardware hacking but this solution seems like it would be a lot less expensive, and probably more fun to build than some, than an equivalent commercial unit.

Link: TheLittleBlackBox: An ARM-based, open source XBMC media center

XBMC is a media center application that started its life as a project to turn the first-generation Xbox into an audio and video powerhouse. The project has since been ported to run on Windows, Mac, Linux, Android, and other platforms, and we’ve even seen it running on low-power devices with ARM processors such as the Pivos XIOS DS Media Play.

Now there’s a new XBMC box on the way, and it’s designed specifically for running XBMC. It doesn’t run Android apps at all, just an embedded operating system to support XBMC.

Full article here:
TheLittleBlackBox: An ARM-based, open source XBMC media center (liliputing)