Note1_PiR_ Side note on the interest of using Single Board Computers in a leisure boat

Note1_PiR

Side note on the interest of using Single Board Computers in a leisure boat

As someone said (maybe in the Cruisers.forum.com, quoting from memory):

                        “ in a boat the equipment is in one of 3 states:  broked, 

                         breaking or about to break”.

Single Board Computers (SBC) are nowadays credit-card sized or even smaller. But with performances close to average consumer computers of just a few years ago. They are everywhere, even in the houses of the more anti-technological persons. And, with the Internet of Things (IoT) they will became even more ubiquitous. Raspberry Pi SBC started by 2012 to be targeted only to promote the computer literacy in schools and poor countries; then they were adopted almost as pet toys by the geeks and nerds; and also more and more used to accomplish very demanding tasks even in industrial contexts. So SBC are small, cheap (just a few dozen of euros) but nevertheless serious pieces of technology. Even in leisure boats SBC have been used hidden in ­­commercial products.

The Sea does not forgive. With irregular and stressing motion paths in all axis. Also, even in the cabin of a cruising boat, large variations of temperature and humidity and the accompanying condensation. Always with salt in the air, more than enough to corrode even the best and protected piece of equipment. A problem in particular for electronics, regardless of  being dedicated “marinized” and thus insanely expensive commercial items or just the consumer gadgets brought aboard by the cruisers.

So, what can we do?

Try to use as much as possible devices with no moving parts, with the least holes/connectors as possible, enclosed in air-sealed cases whenever possible with passive thermal cooling, etc. It might have been  difficult in the past, but nowadays is becoming more and more easily achieved even with consumer appliances.

-       idevices – with no moving parts by default and with less and less “holes” and buttons, thanks to Steve Jobs. Plus, there are plenty of waterproof and shockproof cases around.

-       Computers – the “mechanical” hard drives are now almost completely replaced by SSD (solid-state drives, with no moving components). Moreover it is now quit easy to find computers with no moving parts at all and very few “holes”. Notable example: a few  models of MackBooks.

Right, and what about SBC as the Raspberry Pi series? SBC could certainly find its place in a cruising boat, installed by a geek crew member or by a contracted professional. A few years ago, a few wealthy/tech oriented sailors even installed several hidden MiniMacs to control and manage  on-board commercial pieces of equipment as  autopilots, weather sensors, electronic navigation tools, radio transceivers, etc.

The Ham land based enthusiasts seems to appreciate SBC both as standalone SDR computers to operate in the field, to simplify their home rigs and to run panadapter displays for exploring large samples of the RF spectrum. There seems to be also some interesting applications in remote operation for both reception of raw IQ data and pre-processed audible streams. In a similar way, in a leisure boat, instead of installing an antenna and run a long coaxial cable, subject to all sorts of RF interferences, up to the sdr/computer in the chart table – it might be possible to use a very short coax feeding a waterproof box with a SDR and SBC inside, with just a USB or UTP net cable (digital signals note so prone to RFI) running up to the chart table. Or just feed electricity to the “distant” SDR/SBC through Power over Ethernet (POE).  With a Wifi connection between the SBC and the main computer on the chart table.

Now how often and how many sailors do use such setups in the real Sea world? I have no idea.

Nevertheless my curiosity was piqued by the messages from Conachair and Eric in the cruisers.forum’s thread, “Radio troubles of a sailor and the promises of software defined radio (SDR)”. Therefore, I decided to make some trials at my armchair with a Single Board Computer. So at home I have now two Raspberry Pi units, one 3B with a DAC hat to stream high quality music and one Pi 4B, a brand new candidate to become a sailor.

Setup

            - general setup -  see previous messages, tech2 and tech3

            - Raspberry Pi 4 Model B 2GB running SDRPlay RPi image V0.6

I will post a first review shortly.