I seek to purchase a Raspberry Pi 8 (or a different Pi if recommended by CE) to be loaded with Marine Navigation Software using Open CPN with additional Pi compatible hardware for AIS and other on-board boat-system monitoring bits.
This project is my Christmas present to myself.
The OpenCPN Forum notes had several Pi comments, the most important one (initially) seems to be:-
“Raspberry Pi 2/3/4, 20201206
There are multiple problems reported against the 64-bit arm builds, both Raspian and stock Debian. For the time being, OpenCPN doesn’t support 64-bit builds on ARM.
It looks like I need a 32-bit ARM; is this still the case and are these ARM 32 bit readily available? Has the 64 bit ARM been stabilised and is it the future direction for Raspberry Pi?
The PoE sold by Raspberry Pi appears not to operate from a 12V source (all that I have on-board). Perhaps you have a 12V PoE module that will suffice; an alternative would be USB power and no PoI Ethernet.
Just to clarify what 64 bit and 32 bit means. 64 bit is the number of bits a computer can process at any given time, that being said a 64-bit processor is capable of running 32-bit software. As such you can purchase the latest 64 bit capable Raspberry Pi 4 8GB and run a 32 bit version of raspian/debian (the operating system) with no problems.
Here is a good video explaining the difference between a 64 bit and 32 bit processor.
"Many thanks for the advice, summing up:
Raspbetty Pi 4 8Gb plus a 32bit version OS Raspian/Debian will give me an environment for OpenCPN.
What about powering the system from a 12V battery and taking advantage of the PoE common cable supply; does CE have a hardware DC:DC converter?
Many UI devices use USB; only networking processes use Ethernet; would you advise limiting my power source to USB?"
I’m looking at the Open CPN website and their suggestions on the components that they are using.
Choice of Pi version
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On the Open CPN website, it lists that the 32-bit build is the only supported build, this means that it will still run on Pi revisions 2/3/4 as listed on the site though not running a 64-bit build. Mitchell’s comment explorers the differences between 32 and 64-bit processors (in simple terms a build is when you translate the code so that the computer can run it)
Meaning that the choice is up to you in regards to which Pi you opt for (this guide here features a Pi 3)
Powering the Pi
To power the Pi the post above recommened a Mean well 5V power supply - You should be able to send Core an email to get these special ordered in:
Both of the above should do the trick, wiring them up will be required and a sturdy enclosure to stop corrosion.
You mentioned AIS in your post and the only documentation I was able to find on the OPEN CPN site was for the dAISy HAT. I wasn’t able to find a product on Core’s site that achieves the same thing and no suppliers match up directly. Sounds like you might have to source this one from another supplier.
Other useful resources: https://bareboat-necessities.github.io/my-bareboat/
Let us know how you go!
I would also check out a DC-DC converter or regulator (the Pi uses 5V and can pull up to around 3A depending on the peripherals you are using)
I would try to stick with one IO method to keep consistency. It looks like most systems that are used on a ship are UART or serial connections with a strict information exchange protocol.
Let us know how you go getting everything put together!
Many thanks for your advice Liam, work has intervened on my free time and I am beginning to appreciate how little I know about what I should learn about the basic Raspberry environment. I will put my project on hold whilst I try a little Raspberry education.
No worries Neville,
Make sure to let us know if you have any questions, have a great day!
Core has some excellent tutorials on the Pi and some other cool maker electronic related videos. You definitely seem like you are on the right track.
It might be worth making a post on some OpenCPN forums to see if they can help you with the setup and sourcing parts locally.
Let me know how you go in your searches!