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  Topic Review (Newest First)
12-10-2011 08:29 PM
Bill-Rangatira Duckworks - Building a home made Chart Plotter
found this a while ago
12-02-2011 07:35 PM
IPM Seems we could wire up one of these to the raymarine nema output and have a bluetooth connection! Only a few bucks on ebay.
05-28-2010 08:58 PM
It Works


Today I went down to the boat with my laptop and cable. I connected the cable to the Standard Horizon radio (just 2 wires), and connected it to my PC. I started Seaclear and enabled AIS display.

It worked. Very easy to do and it would be helpful when sailing at night, in bad weather, etc.

05-22-2010 03:16 PM
Success with ST60 Multi NMEA optoisolator circuit

I have put together a simple output circuit as suggested by Norman and tested it on the boat (see attached JPEG file for diagram).

Some notes – The ST60 Multi’s NMEA out + goes thru a 1K resistor in series with an LED (light emitting diode) which in turn is optically coupled to the transistor section of the optoisolator IC (an NTE3041 - $1.49 @ Fry’s electronics). NMEA – is the return from the LED.

On the PC serial port side (I used a USB Serial adaptor – IOGEAR GUC232A) DTR (data terminal ready – pin 4) provides the +10v power to the circuit (DTR is only positive when the serial port is open – ex. When the application HyperTerminal is connected). A 1K resistor is in series with the collector of the transistor. The emitter is connected to the receive pin of the serial port (RXD pin 2) and in turn goes to another 1K resistor to ground of the serial port (GND pin 5)

I ran my test at 4800 baud and all waveforms and voltage levels looked fine.

The ST60 Multi provided the following NMEA messages every 2 sec (while sitting at the dock in San Francisco Bay with a little under 20 knots of wind).

$IIDBT,005.0,f,001.5,M,000.8,F*18 (depth)

$IIHDG,185,,,15,E*1A (heading)

$IIHDM,185,M*30 (magnetic heading)

$IIMTW,013.4,C*25 (water temp)

$IIMWV,092,R,016.2,K,A*28 (wind speed and angle)

$IIVHW,199,T,184,M,00.00,N,00.00,K*59 (water speed and heading)

So now that I have the electrical interface working it is on to my software projects.

05-15-2010 10:32 AM
JimTrez thanks Norman, will let you know how it turns out

05-15-2010 09:41 AM
redline (repost in case editing my previous post doesn't count as an update)

A simple circuit for your NMEA-RS232 could be simply an Opto-isolator, with a 1K resistor in series with the input/NMEA side (the Multi itself uses 4 2.2k in parallel in series with a PC357 opto, say 560 ohms) .

The opto collector goes to +12 (with another 1k or so in series for good measure) and the opto emitter goes to RS232 in. You might need resistor to ground (a 10k or so) on RS232, but usually switching from open circuit to +12 would work even without a negative source.

I hope this verbal schematic makes sense, if so it should only cost about $5-10. Good luck (from a middle-aged (I wish) EE).
05-14-2010 10:01 PM
JimTrez Thanks Norman,

I will try a few things, and will likely wind up with the E85001. I will monitor this thread to see if some young (or old EE) comes up with a circuit idea to tide me over.

05-14-2010 09:47 PM
redline Jim, I did have some success connecting the ST60 Multi's NMEA+ to RS232 RXD and NMEA- to RS232 GND, *AS LONG AS* the computer was ungrounded. See Actisense's comments regarding not grounding the NMEA- in most cases. With the laptop on batteries or even its AC adapter, it worked fine. However when I plugged the laptop into another device on ship's DC, no more NMEA from the Multi.

Perhaps the IOGear is floating wrt ground (we wish) or you could try the Digital Yacht usb-serial-NMEA reviewed on Panbo:

Panbo: The Marine Electronics Weblog: DY NMEA 0183 to USB, looks handy

List price is about double the IOGear but you'd avoid another adapter.

For a time I used a Noland N183-41 NMEA multiplexer, (discontinued version, borrowed from a friend) which took NMEA in and provided a floating NMEA output as well as RS232. You might find something like that on eBay.

Eventually, I broke down and got the Raymarine E85001... it has the advantage of providing many more sentences, as well as NMEA and RS232 out.

edit: Come to think of it (and re-reading your question), a simple circuit for that application could be simply an Opto-isolator, with a 1K resistor in series with the input/NMEA side (the Multi itself uses 4 2.2k in parallel in series with a PC357 opto) then the opto collector to +12 (with another 1k or so in series for good measure) and the opto emitter to RS232 in. You might need a 10k pulldown or so on RS232, but usually switching from open circuit to +12 would work even without a negative source.

I hope this verbal schematic makes sense, if so it's only about $5-10.
I'm off to bilgeclean and bottompaint but would be delighted to prototype the circuit, test and tweak the resistor values in exchange for help with 46' of wax job. ;-)
05-14-2010 08:42 PM
JimTrez I was interested in the comments "redline" made regarding the nature of the ST60 Multi's NMEA out signal. I also observed a +12 on the NMEA+ with a small drop every 2 sec when data is being output. If I connect the NMEA+ and NMEA- directly to a serial to usb adapter no rs232 data is present (this discussion thread explains why). I ultimately want to use the ST60 Multi as a low cost seatalk to NMEA repeater for the instrument messages it does output. I want to connect to an RS232 serial to usb device (IOGear GUC232A) and read the NMEA messages with software I am developing.

I was wondering if there was a simple circuit that would convert the ST60 Multi output to an RS232 signal which could be read by the serial/usb device. Of course I can go get a Raymarine E85001 or a special opto-isolator cable (cost almost as much as the E85001) or even a nice Brookhouse NMEA Multiplexer, but for now I was looking for a low cost simple solution.

I would appreciate any good ideas that would help.


04-26-2010 10:54 AM
thekeip As it worked out, B&G had a big presence at the Strictly Sail Show, here in Oakland, and their senior tech, one Matt Fries, was there too. The owner of the boat in question and Matt discussed the situation and both Matt and another tech visited the boat. It turns out that they felt there was enough reason to replace the CPU. The exchange should be complete by the time I finish this.
Talk about customer
Howard Keiper
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