Tacktick MNEA to laptop

[bromleybysea]

I have Tacktick instruments with a NMEA box. can I connect this to the laptop to display instrument data on the laptop plotter? I know that there is a NMEA to USM cable available at about 40 notes, probably not worth it if that's what it will cost. Is their a cheaper alternative?

 

[maby]

I have Tacktick instruments with a NMEA box. can I connect this to the laptop to display instrument data on the laptop plotter? I know that there is a NMEA to USM cable available at about 40 notes, probably not worth it if that's what it will cost. Is their a cheaper alternative?

Yes, it's easy and documented on the installation sheet for the Tacktick NMEA interface. You'll need an RS232 serial interface port on your laptop - and few, if any, modern machines have one of them. You can get a USB RS232 adaptor very easily and cheaply. This one (http://www.maplin.co.uk/usb-to-serial-9-pin-male-adaptor-29968) from Maplins should work, but I have seen cheaper.

You'll also need a suitable cable - a 9 pin female D connector on one end to bare wires at the other.I doubt you will be able to buy one ready made to that specification, so it's a case of either buying the plug and cable from Maplins and soldering it up, or buying a made up RS232 cable from them, cutting one end off and buzzing the wires through with a multimeter to find out which you need to use.

 

[bromleybysea]

Thanks. I've got a RS232 port on the Thinkpad base so I can connect a serial cable direct to the laptop. I've Googled and looked at the Tacktick interface manual. Any advice on how to connect the RS232 cable to the interface welcome.

 

[maby]

Thanks. I've got a RS232 port on the Thinkpad base so I can connect a serial cable direct to the laptop. I've Googled and looked at the Tacktick interface manual. Any advice on how to connect the RS232 cable to the interface welcome.

If your NMEA interface is like mine, then it's got a five pin plug with screw terminals for the main NMEA input/output port. A lot depends on the distance between the NMEA box and your chosen position for the laptop - are you prepared to leave the cable in place when you are not using the laptop, or do you want to remove it to keep everything neat?

Provided the interface is reasonably close to the desk where you will use the laptop, all you really need to do is to obtain a suitable cable (make, or adapt), and slip the bare wire ends into the plug on the Tacktick, tightening down the screws. If you decide to adapt an off-the-shelf cable, you'll have to cut the unwanted plug off and strip the insulation back. The plugs are usually moulded on so you'll have to buzz the wires through to the remaining plug with a multimeter to identify which is which with reference to the instructions in the Tacktick interface installation manual.

You didn't mention the size of your boat. RS232 is not really intended for very long cable runs and can be a bit vulnerable to external interference. For best results, mount the NMEA box close to the location for the laptop and try to keep it away from sources of interference like the engine, any radio antenna, fridge, invertor etc.

If you want to be able to remove the cable, you'll have to be prepared to do a bit more wiring yourself - there are only three wires required, so you will have to look around for a suitable 3 pin plug and panel mounted socket and drop it in the middle of the connection.

Do bear in mind that the Tacktick NMEA interface is only able to run at the basic NMEA speed of 4800 baud. Some devices will go much faster, but not the Tacktick. You'll need to configure the serial port in the Windows control panel to 4800 baud and may have to do the same in whatever application you intend to use to display the data.

 

[bromleybysea]

Thanks again, that's really helpful.

 

[maby]

If you want to do a professional job and be able to remove the cable when not in use, I suggest one of these plus the matching plug - http://www.force4.co.uk/1041/Bulgin-Flush-Mounting-Socket--3-Pin.html

It's reasonably neat, waterproof (if that matters), large enough to not be fiddly to fit and uses screw terminals, so no soldering. If you get a ready made serial cable that is long enough, you should be able to canibalise it to complete the entire job with no soldering.