We have found the Raspberry Pi to be a cost-effective replacement for the Mac minis that we use in our office to drive TVs that are information radiators.  We use these radiators to display the build status of our ci (continuous integration) projects.  At ~$60 (Raspberry Pi, USB WiFi, enclosure), it’s 90% cheaper than using a $600 Mac mini.

Ordering

• Raspberry Pi Model B Revision 2.0 (512MB).  We ordered from Amazon even though they charged a healthy premium ($47 vs. $35).  We did not want to wait 12 weeks for the unit to arrive (they are still notoriously backordered).
• SB Raspberry Pi Case This case protects from static and bumping. It looks cheap and is not sturdy.  With more time we would have bought this one from Adafruit
• USB wifi adapter
• 32 GB SD card A 4 GB card would be adequate, but we already had this one in our server room.
• Power adapter Again found in our server room.  Cheap USB cables may not work with Raspberry Pi, at least that was the experience of one of my co-workers.  The USB cable that comes with this power adapter works.  I wanted to make sure the same thing did not happen to me as this was also mentioned on Tech Crunch.  My working voltage was 5.022 Volts with a multimeter.  From the same article they recommend a voltage of 4.75 and 5.25 volts and “anything outside this range indicates that you have a problem with your power supply or your power cable.”
• HDMI cable Another server room find.

Setup The Raspberry Pi is different from a home PC/Mac:  It doesn’t have a built in hard drive or flash memory chip; it has an SD card for a brain.

• First, you need to get an operating system for it.  The best place for this is: Raspberry Pi.org. The one I selected is the Raspbian “wheezy”
• I used the instructions found here to setup the SD on my Mac laptop.

Once the operating system was installed I booted the Pi with an HDMI monitor connected.  You will be presented with a screen as seen here from Adafruit.  This is named, appropriately enough, the Raspi – config screen.  Here I selected a few of the different options:

• change_locale and change_timezone
• ssh which enables ssh
• boot_behavior – start desktop at boot
• expand_rootfs

After rebooting, I inserted the USB wifi dongle.  This brought an antenna icon right on the desktop, double-clicking this brought up a menu which let me enter the credentials I needed to access the wireless network.

After completing the wireless install I setup from the Raspi – config screen:

• update – this upgrades the software on the Raspberry Pi to the latest version

To boot the Raspberry Pi to specific webpage at boot follow these instructions:

Boot to browser

Accessing your Raspberry Pi without a keyboard or mouse attached

Our Raspberry Pi’s are connected to TVs with no keyboard or mouse attached; however, we needed to access the console remotely.  Our solution?  We used x11vnc combined with a VNC client so that we could access them remotely.

The following VNC clients will work:

• Apple Remote Desktop
  
• RealVNC’s vncviewer
• homebrew’s tiger-vnc

Apple’s Screen Sharing will not work; it is unable to attach to a passwordless VNC server.

Do the following to install x11vnc which will allow you to VNC into a “headless” (no monitor, keyboard, or mouse connected) Pi from an external machine.  Install true-type fonts for your viewing pleasure.

sudo apt-get install ttf-mscorefonts-installer

sudo apt-get install x11vnc 

sudo curl -o /etc/init.d/x11vnc https://raw.github.com/starlightmedia/bin/master/x11vnc

sudo chmod 755 /etc/init.d/x11vnc

sudo update-rc.d x11vnc defaults

Here is the finished project:

Do you have a wireless network that you want to enable guest access to quickly?  Here’s the scenario: your guest is looking perplexedly at the ceiling [because that’s where the gods of wireless evidently dwell] and giving you that ‘srsly?’ look. Why hasn’t wi-fi magically appeared on their device?  Isn’t this a tech wonderland? Don’t panic, bring the magic.  No Password? No Problem. Instead of making your client do the work of typing in a password for access without his or her glasses, create a QR code to scan instead! They are bound to have at least one QR reader app on their smart device or laptop with camera already.  Keep your guest-wifi QR code printed and tacked up on some wall, eye-level, so the they can scan it and instantly log into your guest network. There, you’ve already made them feel like Pivotal Labs is actually bigger on the inside, like the Tardis, and you are Dr. Who.

How do you generate the QR code from your network?  There are a few different ways. Try an app for the iPhone/iPad called Qrafter or on the Google play store with InstaWifi.  If you would prefer to generate the QR code on a desktop or laptop you can use the website QR4.

One word to the wise:

This is not recommended for a network which you want to keep private. No telling when a bad wolf could infiltrate.

The Problem

Skype connectivity sometimes drops calls. It is also challenging to schedule with multiple people. We already use Google Apps so it made sense since it would integrate with our other systems so easily.

The Fix

We having using Google Hangouts and have been very pleased with the results so far.

The setup is more involved than using Skype so I am going to detail the steps involved.

3 Things have to be done in order to use a Hangout.

1. You first must be a member of Google+. If you are doing this for your @pivotallabs.com Google identity make sure you are signing up with your corporate email address and not your personal Google account. Join at plus.google.com.

2. Enable the Google Video Chat plugin or download from here.

3. Start a Hangout

   • Go to plus.google.com/hangouts and click the Start a Hangout button on the top right side of your screen.
   • Click the Hangouts icon underneath an interesting post on your Home page to start a hangout about the post.
   • Click the Hangouts icon on the left side of the page and click Start a hangout under the ‘HANGOUT INVITE’ section.
   • You can also start a hangout and send and receive hangout invites from other Google properties including:
     Google Chat properties (ie. Gmail, Google+, iGoogle, orkut) Learn more.
   • Google Calendar Learn more.

Neat things you can do with a Hangout

Schedule a recurring meeting with the same Hangout address

This is very handy for a meeting which happens repeatedly so that you always have the same URL to join, like a standup meeting. This was first found by Joe Moore from Pivotal on this blog entry by David Cummings

The steps are as follows:

• Create a new event on Google+ Events.
• Give the event a date far into the future, like the year 2020
• Go to Event options -> Advanced and click on Google+ Hangout
• Save the event
• Share the link to the Google+ Hangout on your repeating Google Calendar event

Get a better quality output if you are doing a live music Hangout using Studio Mode.

Create a Hangout very quickly by using the chat window when signed into your Google email and clicking on the Hangout icon or create an event on your Google calendar and add a Hangout to the event.

Improved Camera

We also found that upgrading the webcam you are using can help to improve your experience. We have upgraded to the Logitech HD Pro Webcam C910. This version is Mac compatible, the newer model which is the C920 is not. The 910 provides improved optics with a better lens and an improved depth of field. This version is also easily portable if you have a laptop.

Summary

We only expect the Google Hangout to get better as Google keeps working to improve it. So far it has been a big improvement over Skype.

The Problem

Our New York office’s sound system was, frankly, awful. It had a persistent background buzz, a loud hum, which we could not get rid of until we re-engineered our audio cabling.

The Fix

We switched to shielded cabling and professional-grade connectors, and when we finished we no longer heard the buzz. And we are able to drive our sound system with an iPhone.

The 50 foot unshielded cables

In our original setup, we had pulled a 50 foot cable over an air-conditioning duct and lighting fixtures. Even though it was a thick gauge wire, it was not shielded.

[Unshielded wires are susceptible to ground loops and electrical interference. In audio cables, this usually results in a background hum or buzz.]

The cable had a 1/4″ phono plug on both ends. This is a 1950s connector which was used on large headphones and electric guitars. Numerous adapters were cobbled together to connect the sound source to the audio system. The results were uniformly dismal: no matter what we played, no matter how it was connected, it always sounded terrible.

The Final Setup

After some research, we settled on the following:

• 2 x 50 foot shielded cables with XLR connectors (professional audio connectors). We used these cables to connect our DI box (see below) to our mixer in the front of the room.

• A direct-in or (DI) box. In our setup, we used a Radial ProAV2 Passive Stereo DI with RCA 3.5mm XLR and 1/4in Inputs.
  

• We also have a Sescom SES-IPOD-RCA03 3.5mm Mini Stereo Plug to Dual RCA Male Plugs. These are used when we need to connect an iPhone or another 3.5 mm jack device. This allows us to play an audio source from the back of the room.