nmea-to-laptop connection for dummies

[yourmomm]

ok. its becoming clear i am an out-and-out novice. but, in my defence, i have searched previous threads with no joy on this one, and google-search just baffled me. i want to connect my phillips ap navigator gps (i think its nmea compatible?) to my usb-laptop, so chartplotting software will work in real time at sea (and also so i can program waypoints using my computer and dowbnload them to the GPS), but being a beginner, i have no idea what cable is required, or how to do it. anyone patient enough to direct me to relevant moron-enabled website and/or (through gritted teeth) give me a solution?? many thanks in advance

 

[alf1]

you will have to buy a cable usb to what connection you have on your gps this will be a phillips part then it just a matter of settings on your gps to nmea and on your software

 

[Talbot]

two options at Phase 1:

get a usb to serial cable and make sure it comes with its own software that works with XP cause otherwise it wont work. Connect GPS through the USB cable. Make sure GPS is set to transmit nmea data (I am missing a bit here abt setting up the comm port which should not be needed for a USB/Serial link.

Alternatively, buy a USB/GPS/Mouse see here This will get round all those horrible problems of connecting up.

Phase 2

You need to establish the identity of the comm port with the GPS data. This can normally be identified through your control panel/system/hardware devices menu. You then need to configure the charting software to acept data from that comm port - if you have more than one on the laptop, make sure you mark the one to use for GPS so that you dont have to go through this every time.

If you are not getting any data, it may be that some other programme has grabbed the comm port and wont allow the GPS to be seen by the programme, so make sure all applications are closed. use hyperterminal to select the comm port and see if any data is coming through.

 

[temptress]

What Laptop do you have and what comms ports do you have?

Most Laptops these days only have a USB port and mosty GPS systems use a serial port. So if you laptop has USB only you will need to:

Get a USB to serial converter (and follow the installation instructions EXECTLY!)- there are many of these available online or PC world usually have them in stock.

Get a 'Data cable' for the GPS (usually comes with a serial plug at one end although I've seem some recently with USB!)

Plug the GPS serial cable into the laptop (or USB converter) serial port

Set the GPS to transmit data (check in it' smanual)

Switch the laptop on and starty the chart program - set this up to use the correct PORT

Somewhere in the setup there will be a 'GPS and or Port' selection - select the settings you have - if you don't know which port you are using it is likely to be 1,3 5 or 7 but just select each one in turn (reboot the computer between each port change to be safe - there are other ways but this is the simplest) untill your chart program sees the GPS and then you are off....

 

[Oldhand]

2 posts advise getting a GPS specific NMEA cable. You don't say which model of aP Navigator you have but as far as I can remember, aP niether supplied or required specific NMEA cables. I suspect your aP has at least one NMEA Tx (transmit) output port and one NMEA Rx (receive) input port. I suspect each port will have 2 terminals, NMEA+ and NMEA- or "data and "return". Refer to you aP manual to identify these. The connections required are as follows:

GPS NMEA Tx+ connects to Pin2 of the PC or Serial Adapter DB9 socket
GPS NMEA Rx+ connects to Pin3 of the PC or Serial Adapter DB9 socket
GPS NMEA TX- and NMEA RX- both connect to Pin 5 of the PC or Serial Adapter DB9 socket

Thus, assuming you join NMEA TX- and RX- together at the GPS and connect Pin 5 of the DB9 socket to either, you need a 3 wire screened cable connected to the NMEA TX+, NMEA RX+ and NMEA Tx/RX- at the GPS and to pins 2, 3 & 5 of a DB9 serial port plug. THe DB9 serial port plug can then be either connected directly to your PC's 9 pin serial port socket (if it has one), or to the 9 pin serial port socket of a USB/RS232 serial port adapter (if the PC hasn't got a serail port).

If your GPS Navigator is an aP6, apart form being a very lucky man, you will find you have 2 separate NMEA input ports and 4 separate NMEA ouput ports (or it could be the other way round - too long ago!) which gives you plenty of choice. In this case it would be best to use any unused ports and make sure they are set to be active in the appropriate manner explained in the aP manual.

On your PC the serial port to which you connect must be configured for 4800baud. Other setting depends on what your PC software expects but the norm is: data bits=8, parity=none, stop bits=1 and flow control=none.

 

[Signed Out]

Would a PCMCIA RS232 port adaptor be more "stable"/user-friendly than a USB convertor? I have a suspicion they would be less hassle, and have seen one (dual port) for £50 in Maplin.
Jem.

 

[chrisgee]

I 1`ve just bought a USB GPS -- just plug in and it works!! no messing about with NMEA etc. Cheap too £79.00 from MESltd .Bristol

 

[Spyro]

Speak to these people for advice WEB PAGE Good prices too.

 

[wbridge]

Dear experts and people cleverer than me

Inspired by this thread(!) , I set to connecting my fixed GPS (a french MLR FX 312) to my Tosh laptop running Maptec Offshore lite charting software . My little (car spec) USB GPS drives it fine , but after several frustrating hours , the MLR still doesnt.

I've bought a USB-Seriel port connector lead which seems to be installed OK , as the Tosh's My Computer device manager's "ports" listing does show com port 9 " huge pine usb to serial port "

the MLR GPS manual describes the seven output leads as follows

blue.......-(ground)
red........+10 to +36 volts dc
orange...reference RS422 (NMEA out)
yellow....output RS422(NMEA out)
green ....reference RS 232
black......Input RS232
white......Output RS 232


I havent penetrated the GPS manual's section on output settings , because having guessed from advice on this thread that the orange and yellow should connect to the seriel pins 5 and 2 respectively ( is that correct , and the right way round ?) I did so , and got what I think is the characteristic "NMEA working OK" voltage pattern between them....ie pulses ranging from milivolts to a couple of volts in cycles every few seconds

but when I plug the USB into the laptop (having disabled other running programmes like viruscan and bluetooth) when prompted by the GPS manual or wizard setup routine in the Maptech programme , I get a "no GPS input found" error .

Help!! what am I doing wrong?!

Advice very very gratefuly received!

Will Bridge

 

[Como]

RS232 and RS422 are different, RS422 being differential and RS232 single ended so the connections you should be using are:-
Green (common ref) to pin 2 of the 9 way connector
Black (RS232 Input) to pin 3 and
White (RS232 Output) to pin 2

Hope this helps.

John

 

[wbridge]

thanks so much

so both green and white to the seriel pin 2............... and the black to seriel pin 3 , not 5 ?

will bridge

 

[Como]

Sorry no, my mistake, the green (common) wire should go to pin 5 not pin 2. The correct connections are:

White to pin 2
Black to pin 3
Green to pin 5

Once again sorry to confuse you!

John

 

[qetoo]

You also have to tell the chart plotting software which COM port the GPS signal is connected to. When I use my USB GPS it connects to COM 5, but when I use my Garmin 128, which connects to the 9-pin connecter, it uses COM 1.