Why have I chosen the Raspberry Pi over one of the many other single board computers that are available?

Project Requirements

• Cheap single board computer with low running costs and total cost of ownership. (TCO)
• Support for alot of digital inputs. (currently i have calculated i need about 50 separate inputs)
• Wireless communication to allow data to be sent to my Splunk instance in near realtime.
• Customisable and extensible, either using add on cards or USB.

Project Decision

There are many single board computers that are available, i looked at the Raspberry Pi, Arduino and Beaglebone Black, all cost under £40 and could all meet my requirements.

Arduino

My initial thoughts were to use an Arduino, they are quite popular at the moment as a cheap unit for receiving sensor data, and triggering relays and like, there is also an active community around the projects that you can do with these devices.

These are fairly basic boards with wireless and USB having to be provided via an additional add on cards, if i was using some form of static collection and upload via SD card or similar then they would of been perfect, but as i want a near realtime data feed for automated analysis, the cost of the required add on cards would of pushed the TCO options available to me.

Beagle Bone Black or Raspberry Pi

OR 

After i ruled out the  Arduino i was left with 2 options from my chosen top 3, the Beaglebone Black and the Raspberry Pi, they both offer me similar functionality.  They have USB port(s) which would give me the ability to use a cheap USB wifi adaptor to send data in near real time.   I am able to run linux on both of these and I am also able to run a Splunk Agent to send the collected data and also a Puppet agent for configuration management and enforcement(more on this later as it may seem unnecessary to some people).

Given that they are both very similar and would both be able to meet my requirements, why did i choose the Raspberry Pi.  Basically the Pi is slightly cheaper as an initial purchase and also has a more active community supporting it.  This means I would have a larger number of options available to me when it comes to decisions later on in the project, I will also have a much richer community that I can reach out to if i struggle to make something work.