DIY Digital Chartplotter

kingfisher

kingfisher

Well-Known Member
Joined
7 Nov 2001
Messages
1,971
Location
Belgium, Holland
Visit site
Here's the plan:

The laptop goes into a cupboard, so water cannot get to it.
The input device will be a wireless keyboard and a cordless trackball (http://www.logitech.com/index.cfm/products/details/GB/EN,CRID=2150,CONTENTID=5006)

But what about the output? I want a digital monitor to receive a wireless signal from the laptop. I know that there are transmitters for a TV signal which can send the signal through a house. My laptop has a TV out. So if I buy a cheap TFT tv (the sort of screen that is used in cars) and send the signal to that and seal it, will I then be able to plot charts outside in the cockpit?
 
Re: DIY Digital Chartplotter... if so simple ?????

Myself and another have been working on this problem for over a year now and if it was so simple we would have marketed it .......
a) The display on a TV LCD is c**p
b) Waterproofing anything that is not designed normally means boxing it in .... heat then builds up and ZAP it stops till it cools down again. That's if you are lucky.
c) The PC and gubbins are not the issue .... we have fanless PC's running direct of 12V .... CD drives, USB, Serial, Parellel etc. no problem ..... wireless mouse, keyboard etc.


The real killer is the display ..... so far the best is the rugged Tablet PC ....
If you have enclosed wheel-house - then no problem .... LCD monitor etc. is OK ..... otherwise it's back to drawing board.

Sorry to be -ve ................. but Jim and I have been working hard at this for so long ....... that cost of a plotter and chart card is cheaper so far .... keeping the PC based version for dry-land / cabin planning etc. In fact what Jim and I have discovered ..... plotter uploaded waypoints / data from routes etc. sorted while planning via PC ..... PC sits in cabin receiving NMEA from plotter in cockpit .... Plotter working on charts via its card ....

You now have best of both worlds .... PC and all its facilities of planning etc. - but able to switch off when you want .... and Plotter still ticking away providing all you want cockpit wise ....

Compomise becomes actually advantage ........
 
Re: DIY Digital Chartplotter... if so simple ?????

[ QUOTE ]
PC and all its facilities of planning etc. - but able to switch off when you want .... and Plotter still ticking away providing all you want cockpit wise

[/ QUOTE ]

That has always been my recommendation. apart frothe advantages of waterproofing and daylight display. This system provides the easiest installation and also the least power use.

I have an additional GPS input to my laptop so that if necessary I can use it as a standalone nav system on the chart table.
 
Re: DIY Digital Chartplotter... if so simple ?????

I'm also trying to setup a similar kind of nav system. I have a laptop which is built into the chart table and hard wired into the electrics. The screen will be on a swivel mount so it can either be directly facing the chart table, or swivelled round to face right into the saloon for watching dvds etc. (also have a 3G card and get braodband on the boat, fantastic for weather reports and getting emergency advice from PBO forums /forums/images/graemlins/smile.gif )

But what I really want to do is have a screen in the cockpit so it can act like a plotter. Like small_boat_champ, I'm finding the screen is the majot problem. A waterproof screen costs almost as much as a plotter, and most normal LCDs are crap in daylight. One option I am contemplating is putting a screen behind a window made from an anti-glare screen filter in the cockpit. But I'm not sure if it would be worth it, and it's a big hole to cut in the boat if it doesn't work well. I may just stick to the laptop down elow for planning, and not bother with an outside screen. To be honest I only use GPS very occasionally, half the fun of sailing is trying to figure out where you are.
 
Re: DIY Digital Chartplotter... if so simple ?????

The best thing about a plotter, is the ability to see it from the helm, especially if you are short-handed and/or its rough.
 
I have more or less such an arrangement, however you will need to use VGA to connect your monitors..ie 15 pin D connector. The small TFT type screens for car DVD use are no good at all, because the quality simply isnt good enough with composite Video.
On the flybridge I have used a 12V white Shop Till monitor 10" Part of an EPOS system, which I bought off ebay, not exactly daylight viewable, but adequate with a shroud. Chart table has a 15" LG TV/Monitor with a VGA input, which is stunning with charts on.
Laptop sits on lower helm, with an active VGA splitter to feed the two remote stations.
Control is by a wireless mouse, although I intend to put something more permanent and waterproof on the flybridge next season, probably a joystick arrangement.
The whole system runs C-map ECS usually, although with this arrangement you can run whatever charts you like.
If you need any more details PM me, but I have been down this road, I have tried converting VGA to composite video etc etc..and the quality loss is too great.

Steve.
 
Re: DIY Digital Chartplotter... if so simple ?????

But the ultimate advantage of the PC surely is the mass of charts available, through programs like OzExplorer and WinGPS, which take any scanned chart or map.

This way you don't have to buy cartridges.

Is there a way to send a VGA signal wirellesly?
 
Re: DIY Digital Chartplotter... if so simple ?????

No, not easily that I know of anyway, unless something new has come on the market recently, but quite long leads are available for it.
VGA sends Red Green and Blue colours independently and also synchronisation signals. I think about 9 of the 15 pins are used. You would have to have one radio channel for each of the signals.
It's easy to send UHF/Baseband/Composite Video as you are only dealing with one
entity.
I know what you want is perfectly achievable, but only by wiring monitors via VGA.

I agree that there is a mass of charts available, but personally I would stay with vector charts, they are so much better,C-map ECS, Maxsea, Seapro, Tsunamis 99,
Nobeltec VNS or Admiral any of these will do.
Programs like Seaclear, OziExplorer.etc..whilst fun to scan charts and set up they are really quite hard work to get it right, and you do need an A3 scanner without an indented bed. Seaclear though is an excellent bit of software.
It's just a shame that you cant now get cheap charts for Seaclear, since Maptech changed to the BSB4 Format.

Steve.
 
TV stuff is no good. Been there, done that, waste-bined it. What works for me is:
Keep the main PC use the VNC program (free of charge /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif) and hook up a second hand tablet PC via a WIFI connection. In a drizzle I put the tablet PC in a ZIPLOCK bag /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif.
 
Problem with all of these is that the tablet PC battery life still is not that good. The fluorescent tubes running the backlight use power even if the computer is low power. Chartplotters use less power to show the chart.
Perhaps we should wait around until e-ink/e-paper is available then you could have a daylight viewable low - power screen. Even a chart table with inlaid e-paper for the real posers who want 'real' charts.
 
Re: DIY Digital Chartplotter... if so simple ?????

There are a number of ways to send VGA data without wires, but the main problem is the display. Excellent displays are available but only if you are prepared to pay.
A Wireless Navigation Display (note: link is a pdf file)is not a bad compromise although this will still set you back around 800 quid.
 
I too wanted to have a second monitor at the steering position but couldnt find a suitable solution, so heres what I settled for
I use maptech on a Toshiba Laptop, set up all waypoints at home and link it with a Garmin 128 gps (no chart) onboard to dump all my routes so they are visible as course to steer from the wheel when at sea.
The laptop is run off an existing 200W inverter when onboard
I personally only need continous view of a chart from the steering position when I'm entering a harbour that I am unfamilliar with, for this I mount the PC on a board that I sit over the companionway under the sprayhood.
The Laptop is kept on the chart table below at sea and is set under the sprayhood and zoomed in for entering harbour so that I can see the map from the steering position. I generally just follow a route in using the track set up in red to assist its visibility. That way I do'nt get messages popping up and filling the screen, and I still have the Garmin course to steer available.
Works well for me as it isnt necessary to have chart detail at sea, just follow the Garmin waypoints. Both systems operate independantly providing redundancy in the event of a failure.
I'm now checking out "Seaclear 2" with a view to scanning paper charts for navigation but with caution regards accuracy. Anyone had any problems with calibration accuracy ????
 
You must log in or register to reply here.

Share this page

Top