Monday, March 30, 2015

Uniqueness of Raspberry Pi 2

Uniqueness of Raspberry Pi 2

There are many websites that discuss the Raspberry Pi 2 specs and what to do with it, but I don't think they position this unique little board properly. Yes, it isn't as powerful as many laptops or desktops, but it does have an excellent role to play in today's computer industry. It is something that will do something, a specific task. It will be used as the internet of things (IoT) evolves. Many people have shown how it can be a server, retro gaming device, media server and more. This quick article expands upon my experiences, especially with audio applications. 

Picked up the Raspberry Pi 2 on the second wave of availability early 2015. Started tinkering with it, first with different standard operating systems offered up at http://www.raspberrypi.org/downloads/ . But I knew I needed to run Ubuntu and followed these instructions for my specific needs to load the Ubuntu 14.04 LTS (Trusty Tahr) OS image and Lubuntu desktop: https://wiki.ubuntu.com/ARM/RaspberryPi .

My initial goal was to run a Digital Audio Converter (DAC) off the small computer. Here is a 3 minute video on the success: https://youtu.be/RF2uRVm19ps . I use FLAC files, because MP3's don't run on Lubuntu due to licensing issues. FLACs are better anyway.

After getting my initial goal accomplished, I played around with the computer more, mostly with audio functions, but also with office activities. 

At the center of this photo is the Raspberry Pi 2 computer. Clockwise from left to right you see a USB headphone w/microphone, a wifi dongle, the jack for a normal set of headphones, the HDMI cable, the power cable, a holder for the 64 Gbyte micro SD card now inside the board (be sure to use a reliable SD card), the SMSL M2 DAC, a powered USB hub that has a wireless mouse and wireless keyboard (transmitters seen in upper right corner).  



There are three types of audio being run off this board, the SMSL M2 DAC, the USB headphone and a normal RCA headphone. There is an additional HDMI audio which I am not using. I am able to control what audio output and inputs are used with the program called Pulseaudio. 

A real eyeopener on the Raspberry Pi 2's functionality was when I was able to make outgoing and receive incoming phone calls using Google voice/hangouts with the USB headphones, for free. No phone service provider required! A wifi dongle (with associated wifi network), the USB headset along with some kind of touch-pad for keying in phone numbers would be all that is needed to set up public phones around the world. 

Because Chromium can be loaded on to the Raspberry Pi 2 under Ubuntu, all Chromium (Chrome) extensions can make this computer very useful. Using Google's Hangout extension inside Chromium I was able to set up the phone. Google Drive, Docs, Sheets, Slides, and all other extensions seem to work just fine. I have run a few music software programs through the Raspberry Pi 2 including Google's Play Music where many of my own music library files reside for free.  When using Google Play Music off Chromium my music files come in quite nicely, and if using the SMSL M2 USB DAC as the output, the sound is quite good through an amplifier and nice speakers. A completely acceptable alternative is the normal headphone jack. From my perspective, this Raspberry Pi 2 can be a public jukebox, playing music from places like archive.org continuously. Want to stream every Grateful Dead concert over a PA system, forever? 

There are a few Youtube videos that can help to optimize Chromium for this  Raspberry Pi 2. I enable only the extensions I need. These include Mightytext, an extension that adds SMS text messaging to gmail though my phone. Very useful to immediately reply to text messages with this Mightytext function. Youtube videos are a place where the Raspberry Pi 2 does not work well yet. Using the lowest resolution helps some. I'm betting when the four core processors on this computer are optimized for utilization, then Youtube will work fine. 

This small computer will work with nothing more than a 5 volt 2 amp power supply which is the specification. That is 10 watts, but something like 4 watts of power is all that is really needed. A very small solar panel and small battery can keep this computer running all day long, remotely, anywhere in the world. Weather station, wifi repeater, and these sound applications I have written about make the  Raspberry Pi 2 a unique computer which is going to be used for specific stand alone applications. 


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