understanding electronics

[letterman]

I'm watching the Super Bowl and reading West Marine catalogue at the same time, just looking, page by page, to see what I missed, or to recall something I would lke to get for the boat. Then it hit me, so i went to the net. I found a guy in Sweden who made a darn good sidescan sonar unit using a fishfinder. It wasn't what I was looking for, but was intersting. WHat i wonder is if a laptop costs, say, a $1000 (one boat unit). We all know what they can do. So why are fishfinders in the range of $150 to over $2000? They must use a pulse signal, then somethng to put it on, like a LCD screen. The have to have a chip, programmed with software, to work. So why can't you just have a laptop computer on board that has multiple screens, and can do every item, like depth, navigation, aparent wind direction, wind speed, boat speed, etc. One unit to replace them all? If yo add up all the other stuff, it must total $5k-7k. Yet they all have computer type screens, or so I think, they all have a chip with impregnated info, or so I think, and they all have some function unique to them (the fishfinder/depth finder sends out a pulse)...so, can you do it for cheap? One computer, multiple functions?

 

[Ross]

like so many things in this world it depends.

It depends of the format of the information coming from the data collectors i.e. depth, wind, flux gate compass, GPS, speed. Are they in a format that the computer can use? Can you write a program for the computer so that it can use the data? Probably the best place to start would be the local community college with some computer courses in this direction. There are interfaces for all manner of operation using computers and the sum of my real knowledge is that a great many cables and some magic are involved.

 

[Calif. Ted]

This is what is hoped to be gained with the new

NMEA 2000 standard, "The Open Non-Proprietary Industry Wide Standard". So that every instrument from fishfinder to waste tank gauge all run on a single buss. I've attached the website, kind of a dream right now but the good thing about progress is that it's always accelerating.http://www.nmea.org/pdf/NMEA2000info.pdf

 

[NautiDuck]

Good idea, but

Your $1k laptop is not weatherproof. We buy Panasonic Toughbooks at work for outside and they cost up to $5k. Even a Dell tough model is nearly $3k. Then you got the issue that laptops suck battery power at an alarming rate.I like your idea and we will eventually get there. In the meantime manufacturers like Raymarine sell devices like the C70, C80 and C120 that allow all of you GPS, sonar, radar to be hooked up to one weatherproff screen. That is what you are after. I work with computers and, at this point in time, I wouldn't want to have all my navigation eggs in a laptop basket. My .02

 

[Bill Roosa]

Raw data vs messages

Message type dataIt is usually possible to multiplex several sensors together if they share a similar format for their messages. Seatalk, NEMA 2000, others can all be run together IF you want to do such a thing. The economics do not support buying the cheapest sensors and multiplexing them however. It is still cheaper to just buy sensors with one type of message format than to build a multiplexer.Raw data.The raw sensor data can be decoded with a computer but the problem there is you cannot multiplex the data lines. You need a dedicated line due to the timing data being sent. If you mix two data streams your timing data goes sideways and you get less than desired results. And since most computers only have 1 or 2 input ports the limit is 1 or 2 sensors. And be prepared to write some code so you will be needing a compiler, linker, and a text editor at the very least.And a book to tell you how to write generic codeand some God like source to tell you the proprietary format that the sensor talksand a far bit of patience, because life on the bleeding edge is just like thatand an understanding spouse as you will be behind the computer a LOTOr you could go sailing using a lead line, some yarn and the senses God gave you which, IMHO, sounds like a lot more fun.

 

[OTG]

Doable..

Only need to design/build a interface card to accept signals from all on board sensors plus a Windows application program. Laptop isn't my choice because the keyboard would limit where you can install the monitor. A mini-PC would be more suitable for which you can have multiple monitor installation and I/F expansion capability. If not taking the labor cost, a micro-controller based I/F card for such purpose could be build for less than two hundred dollars maximum(Windows software excluded.)

 

[Ralph18414]

Weatherized Bulkhead Mounted LCDs

It would be awesome to have a weatherized 17" bulkhead mounted screen plugged into a computer with all the nav and radio crap feeding it. It would be fun to watch DVDs in the cockpit when relaxing in the evening.I recently installed numerous wireless cameras around my house that feed into my computer via a specialized router. I am able to keep an eye on my house from the office. The cameras are the day/night kind. I would really like to use the same system on my boat. The marina has wifi that I keep my boat at. It would be awesome to put a camera inside the boat looking at the bilge and a pan/tilt camera or two up on the spreaders so that I can keep an eye on the dock lines. Has anyone done this?It makes sense to have a compute on board.

 

[NautiDuck]

Raymarine C series

Does most of that stuff including supporting video cameras right now. Marine electronics are expensive because they are waterproof and stand up to lots of motion, salt water, etc. Plus, you want easy-to-use buttons so you are not clicking and dragging a mouse around. I work with computers every day. They are wonderful for some things, but no way would I run all all of a boats nav features through a Windows PC or laptop. Sometimes, built-for-purpose is best.

 

[T J Furstenau]

Electronics Wishes

Reading this thread got me thinking of one of my biggest electronics wishes. I do computer work for a living, unfortunately not the hardware/software/driver type that would allow me to build this myself. What I would like to see is Bluetooth/RF/WiFi type sensors and displays to simplify the installation, upgrading, and maintenance of the electronics. Imagine them all talking NMEA 2000. Wouldn't it be nice to be able to add or replace a component simply by bringing it to the boat and identifying it to the network? No wires for signal (obviously would need power). The typical signal range ought to fall into the size of most boats. And I could have my Raymarine wind and speed talking to my Garmin GPS, relaying info to my Simrad autopilot, showing data on my LCD monitor, including info from my Icom VHF. Okay, a pipe dream? Yes. All the manufacturers prefer proprietary, as that locks you into their brand, but it's still fun to dream.T Jps - If any of these guys do come out with this, remember that you saw it here first and I want my cut for the idea!

 

[Steve Kamp]

The concept

is not new, and has been applied to similar electronics in a different hobby, Model Railroading. The application took cooperation from the industry manufacturers and demand from the consumer, the model railroader. It is called Digital Command Control, and allows the independent control of a large number of locomotives, sound and light effects, track routing and PC interface via a master control box and individual decoders with specific addresses. The system uses a common bus (the track) and low voltage AC to carry the commands to the decoders. I am not an electronics engineer and will not ever pretend to know any more about it than what I have described, but I have seen it in operation. If you are interested in more info, look up the National Model Railroad Association and DCC. It is way more than I can get my teeth around; I'm content with being able to find the wires to the battery.Steve KampHunter 38 Carolina

 

[Alex]

Electronics

I use a laptop (with pelican box), a portable printer and a USB GPS in the nav station. I print the necessary chart for the day and put them in plastic sleeves for the helm. At the wheel, I have a Garmin 76 GPS.For the web cam, I am investigating a system for the yacht club after the recent string of breakins. The web cam has to run on solar panel and battery so the boat in the yard doesn't have to be plugged in.

 

[NautiDuck]

Found it!

This does everything you want, right?