Originally Posted by rgleason
I liked Sean's ideas but would be challenged putting it together even with his plugins.
Sean's cost estimates may be correct for his part of the world, but for some of the accessories possibly a little low for the UK once delivery
is taken into account.
That being said the pi route
is still cheap
, viable, and most importantly for me, flexible. If the OP already has AIS
(as I do) then the sdr can be taken out of the equation and things become simpler. My current
set-up consists of the following:
- raspberry pi v2 (my original model B suffered from intermittent hangs when the USB got loaded)
- Edimax Edimax EW-7811un wifi adaptor: really small and can be used to create an access point. No-name adaptors with the same chipset can be had for under €10 delivered on ebay
- usb to serial
adapter for the ais. My AIS has an rs232
out, but you can buy rs422 to usb adaptors with terminal blocks if you're dealing with bare wire output.
- A usb gps
would work but I'm using an adafruit usb breakout board connected to the pi's UART (for reasons discussed below). The OP could use another serial
to usb adaptor (or a multiport serial to usb adaptor).
- I'm currently using a 12v cigarette-lighter-to-usb adaptor and usb to micro usb cable for power, but have a very cheap
12v to microusb adaptor I intend wiring
in to make things more permanent
- micro sd card (I have 32GB, 4GB is plenty). Case (mine's a nice one which set me back €18).
- powered usb hub. Probably unnecessary but there because I also have my "external" big antenna
I use kplex to do all the multiplexing (it'll also do prioritised failover between GPS
sources if you want that). I can get my NMEA data over IPv4, IPv6, TCP or UDP. If I had a pre-existing boat network, the pi could join it. I don't, so it acts as an access point. I also have an "external" USB adapter: By connecting to the outside world via the pi, not only do I get increased range, but also it appears as though I have a single
connection to the marina wifi (which is all my marina allows per boat) when multiple devices are connected internally.
Why not the simple cheap usb GPS? No PPS wire :-) I don't own a watch so have to make do with this:
# ntpq -p
remote refid st t when poll reach delay offset jitter
*GPS_NMEA(0) .GPS. 0 l 14 16 377 0.000 -88.257 42.720
oPPS(0) .PPS. 0 l 12 16 377 0.000 0.002 0.002
Then there's all those other geeky projects for when it's raining. I also have the pi linked up to the stereo and am using shairplay to play tunes from my mac or iPod (though even with an additional cheap usb audio adaptor I still have unresolved noise
..but I'm getting carried away. The primary purpose is to multiplex nmea-0183 data and send it wirelessly to a laptop
running OpenCPN (or the tablet I don't yet have) and it does that admirably for under €100 all in.
The vYacht offering seems a really good value proposition for anyone who wants something more plug
and play. Bernd seems like a very smart guy. If I didn't like mucking about with this stuff that device would be high on my list of candidates for this task.