Navtex from HF to wifi?

Ric

Well-Known Member
Joined
8 Dec 2003
Messages
1,723
Visit site
Does anybody know of a solution to receive Navtex from HF and transmit it onto boat's wifi network?

There are plenty of Navtex apps for tablets and laptops but all require an internet connection.


Navtex HF transmissions are remarkably reliable well offshore - but the only solution I know of to read the signals on non-proprietary hardware is NASA's windows PC engine. I would really like an option to convert to wifi to read on an iPad.
 
Thank you, but that is not really very practical. Ideal solution would be a box with antenna which can receive and store Navtex messages, which can then be accessed when required by iPad.
 
Ideal solution would be a box with antenna which can receive and store Navtex messages, which can then be accessed when required by iPad.

Not sure if they have that exact thing, but it's the kind of area that Wetterbox operate in.

Pete
 
It's funny when you read about the Navtex app that brag about not needing a HF receiver, only an internet connection. :) Doh !

There doesn't seem to be a device that does what you want, nearest is the NASA PC Navtex USB. That of course only gets it onto a laptop, not your iPad. If you only want it on the iPad for convenience and have a Laptop onboard you could set the iPad up as a laptop repeater. Not sure exactly how well that would work and it is a little messy, but at the least you'd have Navtext on a laptop for £135.
 
Not sure if they have that exact thing, but it's the kind of area that Wetterbox operate in.

Pete

I had a look at the Moerer devices and they seem really clever and versatile - except that they too are built for Windows PC. I really don't want a PC on my boat!!!
 
I would imagine it would be relatively simple to build a device to interface to a NASA unit. I've got too many projects on the go at the moment, but it would seem an ideal job for an ESP8266

The NASA unit appears to output via a RS232 socket, using a serial to USB cable for the PC connection. If that is the case, one of these will do the wifi bit :

http://www.ebay.co.uk/itm/172226270127?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

The issue then is having something on the iPad to deal with the Navtex data.
 
The NASA unit appears to output via a RS232 socket.

Does the NASA unit store the data, to be retrieved whenever you want, or does it output the messages immediately they arrive so that you need something running 24/7 to collect them?

Edit: I see it's the former, but that means you need NASA's own special (and rather clunky) software to talk to the thing and retrieve the messages. No chance of doing that from an iPad unless you reverse-engineer NASA's protocol (it is at least probably fairly simple) and then write your own iOS client. Not impossible, but I think I'd rather see about mounting the WetterInfo box as USB mass storage and then offering its contents up through a tiny web server. Nigel's suggestion might be just man enough to do that, but if not there will be plenty of alternatives out there. Raspberry Pi if nothing else, though that's a little overkill.

Any solution is going to involve a certain amount of development, it seems there's nothing off the shelf. The simple answer would be to forget the iPad and fit an ICS Nav6 :)

Pete
 
Last edited:
It's not like plumbing :)

You can't just hook up something with an RS232 plug on it to a serial to Wi-Fi converter and expect anything meaningful. You need something intelligent in between to organise the data.

Would it not just receive the data and re-transmit it (so to speak) via wifi, leaving the receiving device (iPad) to do something with the data ?
 
The nasa navtex engine stores all the messages that it receives. Just send it $S (rs232 38400 baud) and it sends out its entire memory contents.
There are a few other simple commands details of which are freely available from nasa.
 
Why this urge to have everything wireless on an iPad? To stay longer in one's bunk perhaps!
I've got a device that receives and stores Navtex messages and displays them at the touch of a button. It called a Furuno NX300.
Probably cheaper than all these converters, interfaces etc etc.
 
I've got a device that receives and stores Navtex messages and displays them at the touch of a button. It called a Furuno NX300.
Probably cheaper than all these converters, interfaces etc etc.

Probably not, actually - this stuff is remarkably cheap.

Definitely a hell of a lot easier, though :)

Pete
 
Probably not, actually - this stuff is remarkably cheap.

Definitely a hell of a lot easier, though :)

Pete

Definitely not cheaper, the Furuno is over £500. Could do it for half that with the NASA unit and a 2nd hand laptop, which would be easy enough to setup. Or at least it should.
 
There are several android apps that DO NOT need the internet but read the audio from the HF radio and display. They will also ignore signals you do not wish to display. Some just use the mike and others will as also use a simple interface. A search on Plastics brings them up.Check out Droid.
 
Top