SOURCEFORGE » RALF » 2015 Satellite emergency small terminal

h1. Single-board computer

!http://cdn2.expertreviews.co.uk/sites/expertreviews/files/styles/article_main_wide_image/public/2016/02/pi_3.jpg!

Our single board computer is the brand new Raspberry pi 3. This computer is interesting because it is no bigger than a credit-card (although quite thicker), and packs quite a punch in terms of processing power.

This computer embeds a quad-core ARM A family processor, at 1.2Ghz, with 1Gb of RAM (shared with video memory). This third iteration of the raspberry pi even embed wifi and bluetooth connectivity.

Hopelessly, a big caveat remains in this board: since the first raspi, the SD card reader did not evolve and even back then, it was not a top notch one, meaning that we need to cope with a mass storage maximum throughput of 22MBps, which is very restricting.

Here is a comparison of various SD card, when used in a raspi. The maximum of 22MBps isn't even closely reached.

!http://tof.canardpc.com/view/e824348b-2f43-4def-82f3-2901b0a95dbd.jpg!

This bottleneck impacts quite a lot the capabilities in terms of running the various applications that may be of use on the field.

Because of this, we think a further iteration of this microbox should begin by studying alternatives to this computer.

In particular, we were interested in getting a banana Pi, which is very similar to the Raspi, but interestingly embeds a SATA connectivity (both data connector and power connector, although the power option needs an adapter and is only able to deliver 5V, not 3.3 nor 12).

With this computer we would have brought a 2.5'' SSD that would have yielded a lot more than 22MBPS (possibly around 5 times better). Unfortunately that was not the chosen option, first because of price (twice the one of the raspi), and second because the banana Pi 2 is expected to be available in a few months.

!http://tof.canardpc.com/preview2/e733944c-bab3-4a5b-8351-0e6315c0ec03.jpg!

Still, this computer will be able to serve a few applications (most of them have been developed using web technologies, which gives a lot of flexibility in how we get access to them. smartphone, tablet and PC for instance are fine, as long as they have a web browser), and can be configured using SSH.

Connecting to the raspi using SSH is very easy thanks to its fixed IP. From there, a full shell is given, meaning that anything can be configured.

We were also provided with a high-end case for this computer, with an integrated 3.5'' touch-screen. It may be used in the future to display various information, either network-related or application-related.