Like me, you may be considering creating a project for the NMEA2000 bus. You can take some different approaches. No I won't send you a NMEA2000 primer. I would like to hear from successful developers on the marinette site (www.marinetteboat.com/forum electronics thread).
My boat has 2 Murphy
www.fwmurphy.com Helmviews (with 3 bus types – J1939, NMEA2000 and Modbus) connected to new 2007 Crusaders. The system needed a specialty wiring harness.
The easiest is to buy a USB adapter for NMEA2000 and connect it to a PC. We'll assume you can program in BASIC or C. If you have never programmed anything before, you can start with a USB adapter and create a useful PC program. Remember, in order to do anything useful, you need something to measure or control. Reading the fuel level (PGN 127505 message) is probably the easiest thing to program, but you will need something to connect to (a fuel tank sensor) like Maretrons, or others. A PC based approach to getting into the bus is much simpler to program. Look for something that has a Application Programming Interface (API) that is easy to program with in a language you like. Most of these are C or C++, but you can find BASIC API's. Lawicel and Kvaser LeafLight make excellent generic CAN based adapters and Mareton makes an NMEA2000 bus adapter. If you know how to program windows and Visual Basic or C#, these can be excellent choices. Microsoft has free versions of these compilers. Someone will mention using embedded GNU c++, it's great for an experienced user, but will turn off many first timers in the configuration and setup of the platform for building.
If you have never built any electronics or programmed anything – get a learning kit from Parallax called the Basic stamp (also at Radio Shack). It teaches basic concepts like sensors and controllers with an easy to follow manual under 100 bucks. Worth every penny, even though it won't get you connected to NMEA2000 systems. You can still build useful projects with a Basic Stamp. A good choice might be a bilge alarm (A parallax basic stamp is very close to the PIC microprocessor line). NMEA2000 is very close to automotive technology so many of the 2 year college training courses at community schools apply as do their textbooks. Since I have GM based engines with MEFI 4 (Crusaders) that are J1939 compliant engines I can use the Murphys to do a lot.
I decided to go the embedded systems route first. I wanted to learn a processor that had a lot of good features. I had 2 real choices – Microchip PIC 18F (which has very good hobby support) and ARM (my choice) which is closer to a manufacturer choice. My best choice would have been PIC, as they already have a free J1939 stack (link located on my site or go to
www.microchip.com) and they have a very good C and Basic compiler for that chip by Mikroe. A small manufacturer could start here with little investment –
http://www.mikroe.com, using the BigPIC or Can system. It's hard to avoid C programming in this area. I recommend getting a PIC and some of the many good PIC books. A generic book on the subject is
http://www.oreilly.com/catalog/dbhardware2/ designing embedded systems. My project based on Luminary Micro's 8962 evaluation board is going slowly.
My project is to first build a reader of fuel level for 2 tanks using the NMEA2000 bus for indicators at the back of the boat. (No fast or extended messaging is needed). Other than registering the device and isolating it, it should be simple. I will probably adapt the Rochester gauge senders with Maretron sensors or use the LM 2101 board to create a sensor pack.
If you are just starting with electronics, learning embedded systems is a bit harder, so start with something easy. I do this for a living (but not CAN), and yet still should have started with something easier. Get as much research as you can done early. I found I should have investigated more on the starting point with a chip manufacturer microchip who already has a very close stack.
Good luck. I won't send you a copy of the NMEA bus primer, as it's intellectual property of NMEA.
Unzinced ships sink at slips. yep
