Seaclear to ST1000+ Connection

[kpgraci]

Finally got all the kinks worked out of my seaclear to ST1000+ connection.

My seaclear laptop (a 10" dell mini) has a build in GPS receiver but no COM ports, so I got a USB to Serial cable, then I built a cable to connect the COM port, the VHF, and the AP. My first attempt failed, so I purchased a RS-232 tester which fits in line and lets you 'see' the activity on each pin. As it turns out the Radio shack D-sub connector I used is really poor design with how the pins fit into the connector, but after some troubleshooting I finally got a good connection. I left the RS-232 tester in place and it provides a nice visual confirmation that data is available and moving on the cable.

So then I set up Seaclear to passthrough the GPS data, and set it to also send Waypoint data. More trial and error here, at first I was not getting crosstrack data to the AP, so it took some tweaking of the settings in seaclear.

End result, my VHF now knows where I'm at, and my Autotiller can acquire and hold a route entered in Seaclear.

I've attached the wires so they remain in place and I have a USB cable at the 'nav station' that the laptop plugs into to connect it to the system.

The ability to lock onto a route is a vast improvement over just a heading lock, because it eliminates leeway. It's also nice to be able to look at the tiller and see crosstrack error and distance to next waypoint.

I just love it when a plan comes together. :dance:

 

[emergpa1]

Finally got all the kinks worked out of my seaclear to ST1000+ connection.

My seaclear laptop (a 10" dell mini) has a build in GPS receiver but no COM ports, so I got a USB to Serial cable, then I built a cable to connect the COM port, the VHF, and the AP. My first attempt failed, so I purchased a RS-232 tester which fits in line and lets you 'see' the activity on each pin. As it turns out the Radio shack D-sub connector I used is really poor design with how the pins fit into the connector, but after some troubleshooting I finally got a good connection. I left the RS-232 tester in place and it provides a nice visual confirmation that data is available and moving on the cable.

So then I set up Seaclear to passthrough the GPS data, and set it to also send Waypoint data. More trial and error here, at first I was not getting crosstrack data to the AP, so it took some tweaking of the settings in seaclear.

End result, my VHF now knows where I'm at, and my Autotiller can acquire and hold a route entered in Seaclear.

I've attached the wires so they remain in place and I have a USB cable at the 'nav station' that the laptop plugs into to connect it to the system.

The ability to lock onto a route is a vast improvement over just a heading lock, because it eliminates leeway. It's also nice to be able to look at the tiller and see crosstrack error and distance to next waypoint.

I just love it when a plan comes together. :dance:

Pretty cool. I'm just beginning to try and learn about navigation and nav equipment. Thanks for the post.
Keith

 

[Shoaldrafter]

Seaclear

Pretty cool. I'm just beginning to try and learn about navigation and nav equipment. Thanks for the post.
Keith

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kpgraci,

Nice post. I suspect that there are more lucid posts about what you are doing and how it works, but I would appreciate your first hand explantions of what equipment you have, how you knew what to connect to where, you know some of the details for us not so technically astute...

Ed K
Addendum:
"According to Health Magazine the most popular assault weapon in the United Kingdom is the beer glass. Naturally, there is now a move afoot in Britain for "beer glass control." Jeff Cooper

 

[Technodad]

Ken
Thanks for your description of connecting all 3 items together.
My older gps has a NMEA1083 output but the sentences do not contain enough info (older version) and have not been able to connect up.
I have a notebook computer that I have Seaclear on also, thanks to you, now I can provide my VHF and ST1000 with the Seaclear 0183 output.
Great!!! I never even thought of doing that....

John

 

[cb32863]

Pics, parts list, and screen shots of the settings in Seaclear would be a great addition to this thread.

 

[Joe11688]

That's a great accomplishment Ken! I'd like to try something like that with my ST 1000+ but I hate to part with my Standard Voyager Horizon VHF that I bought back in 1987, and my trusty hand held Garmin 12.

 

[kpgraci]

Right, thanks for the interest. I'll get some pics of my setup and include details of the hardware and seaclear settings and post them this weekend. It's one of those projects that took me a while to figure out, but once it's done it seems so simple.

OK. If it seems longwinded just remember, you asked for it. I tried to give some background information as well, I’m sure I’ll soon forget all this stuff but it fresh in my mind for now. There may well be errors but I believe everything I say is accurate.

I’ll post some pics this weekend if I remember to bring the camera.
Here’s how I got my GPS enabled laptop running Seaclear Chart Plotter to communicate with my VHF Radio and my ST1000+ Auto Tiller.

Some background

Seaclear is capable of receiving GPS and other NMEA 0183 sentences (from a wind vane or compass, for example) from up to three COM ports, and can relay some or all of this NMEA data out one of the computer’s COM ports. In addition, Seaclear can generate NMEA sentences needed by an autopilot to follow routes created in Seaclear (waypoint, bearing, and crosstrack error information).

My DSC capable VHF Radio and the ST1000+ can accept this NMEA 0183 data. There are other NMEA protocols besides 0183, NMEA 2000 for example. Different NMEA protocols are generally incompatible with each other, so you need to be sure all your equipment works with the same one. Since Seaclear and the ST1000+ uses NMEA 0183 that’s all I’m concerned about here. There are also two different wiring schemes defined for a NMEA data bus. The older scheme uses two wires, a positive data, and a ground, and operates at 15V. The newer scheme uses three wires, a positive data, a negative data, and a system ground, and operates at 5V. The ST1000+ uses the older two wire setup, and that also corresponds to how a computer COM port sends data, so that’s what I’ll talk about.

CAUTION: Because of the different voltages involved you should not connect equipment that uses older and newer NMEA wiring standards directly together. There is a lot on the Internet about how to construct a safe NMEA bus to do this, well beyond the scope here. In my case everything is old NMEA bus so the cabling is quite simple. Note that some Internet sites recommend using optical couplers even in a same standard NMEA bus environment, your call; I thought this was overkill for my purposes and opti-couplers drive up the cost considerably. Everything I do here is directly wired together using some speaker wire I had laying around.

Equipment Needed

The basic equipment for the setup is a laptop with an internal GPS card or an external USB GPS puck, a DSC capable VHF radio and a Raymarine ST1000+ or ST2000+ Auto Tiller, and of course, Seaclear installed on the laptop.

Here is a list of my specific equipment:
Dell Inspiron Mini 10 with built-in GPS option
Cobra MR F45-B Marine VHF Radio
Raymarine ST1000+ Auto Tiller

Other parts used:

For connecting the computer to the NMEA Bus:
USB to COM Port Cable (http://www.cablestogo.com/product.asp?cat_id=101&sku=26886)
Female D-Sub connector (Radio Shack276-1428)
D-Sub enclosure hood (Radio shack 276-1539)

The NMEA Bus:
Two conductor speaker wire

For connecting the Auto tiller to the NMEA Bus:
Female 1/8” mono inline phone jack (Radio Shack 274-333)
Male 1/8” mono phone plug (Radio Shack 274-286)

For connecting the VHF Radio to the NMEA Bus:
Male 2.5mm mono phone plug Radio Shack 274-289)

Note: The Male 2.5mm mono phone plug is used to plug into the GPS jack on the
back of my VHF. The radio came with a cable for this but I have since lost it. Point is, you may need a different way to hook to your radio if you’re going to do that.

Optional equipment:

RS-232 tester (http://www.amazon.com/RS-232-link-Tester-DB-9-Female/dp/B004OT995U)
A serial data cable (DB-9 Male/DB-9 Female)
Multi-meter with a diode (connectivity) test setting

Note: I would highly recommend getting the RS-232 tester, it’s cheap ($20+shipping) and provides visual feedback that the computer is sending data, otherwise if things don’t work you’ll have no way of knowing if data is even being sent out the COM port or not. Of course you have no way of telling if the data being sent is the correct data, but for this you can use Seaclear’s NMEA output viewer, more on this latter.

Creating a COM port of a computer that only has USB ports.

This is where the Cables-to-go (or similar) USB to serial cable comes in. If your computer has a COM port (I doubt it) then you don’t need this. The product comes with a driver disk, and after installing the software, by plugging in the USB cable it creates a virtual COM port on the computer. You need to know the number of this COM port so you can setup Seaclear properly. To do this in XP, right-click on My Computer, go to properties, hardware, device manager, then open Ports (COM, LPT). The new COM port should be listed there. On windows 7 this is the same, but getting there is different. On my computer the new COM port is COM 8. NOTE: if you plug the cable into a different USB port, the virtual COM port number will be different each time. So always use the same USB port on the computer to plug into and you should have no problems. Otherwise just open up the device manager to find out what it is, and set Seaclear appropriately.

Building the NMEA Data Cable

Per the Seaclear documentation, Seaclear will send NMEA 0183 data out a designated COM port on Pin 3 (TX) and Pin 5 (GND). So we need to build a cable that connects these two pins to the two conductor wire.

For this I used the Radio shack 276-1428 Female D-sub connector, a marginally designed product if ever I saw one. It comes with the female 9 pin molded connector, and a separate stamped and formed set of pins that need to be inserted into the connector. The concept is fine, as I only needed two of the pins there was no need to ‘pin up’ the unused holes in the connector, but this is where I was getting a connection failure. The male db-9 from the computer (or the Cables-to-go cable) that plugs into the made up Radio Shack connector was not making proper contact with the pin receivers. This was because I had not shoved the pin connectors far enough into their respective holes, and this was because my crimping and soldering job on the pins was a bit bulky. This is where a multi-tester with a diode check function comes in handy. Now, it would seem that it’s straight forward to test the connection with the multi-tester, but the D-sub female connector needs to plug into the computer or the Cables-to-go COM port cable and so there is no way to test the connection like this. So I used a factory built COM port cable I had laying around to mate to the radio shack db-9. That allowed me to test to cable to cable connection and once satisfactory I screwed the connectors together. Then I plugged the factory COM cable into the computer (or Cables-to-go cable) and went on faith that the connection was good at the computer end.

I ended up inserting the RS-232 tester in the circuit as a permanent fixture. As I mentioned this is great for ‘watching’ the data on the wire. As it turns out, the cable can be tested end to end with the diode checker even with the tester in place because it just passes through the signal. Very Nice.

To connect the two wire NMEA cable to the VHF, my radio requires a 2.5mm mono plug. Although not specified in the radio documentation, I assumed that the tip would be positive and the ring would be ground. So the positive tip connects to the wire connected to COM port pin 3 (TX) and the ring to the wire connected to COM port pin 5 (GND).

Now I also want to piggy back the ST1000+ on this connection. The NMEA wiring standard allows for multiple NMEA Listerners (the VHF and ST1000+ in this case) to be connected to a single NMEA talker (Seaclear) so it’s just a matter of daisy chaining the connection. To allow the Tiller to be added or removed from the NMEA bus at will, I attached a female 1/8 inch phone jack to the wires from the computer, again with the tip positive and the ring as ground.

The ST1000+ documentation shows that pins 5 and 6 of the Auto tiller connector are used for NMEA 0183 data. To hook this up I build a separate cable using the two conductor speaker wire, with a male 1/8 inch phone plug wired to the ST1000+ connector. Tip (NMEA +) to ST1000+ Pin 6, Ring (GND) to ST1000+ pin 5.

So the final cable configuration is:

Computer USB Port -> Cables-To-Go serial cable -> Factory Built Serial Cable -> RS-232 Tester -> Radio Shack DB-9 Connector -> two conductor speaker wire -> Split into: a male 2.5mm mono phono plug and a female 1/8 inch mono phono jack => VHF and ST1000+ respectively.

Seaclear Configuration

My GPS provides data on COM 4 and my Cables-To-Go- virtual COM port is COM 8. Your ports may be different, but the setup is the same otherwise.
In Seaclear, go to Tools –> Properties, then click on the Comm tab.

Under Tx1/Rx1, set the output COM Port, this is the one created by the Cables-to-go cable, in my case COM 8, Set BPS to 4800.

Under Rx2 set the GPS input COM port, in my case COM 4. Set BPS to 4800.
Leave GPS Datum settings blank, if it has something in it, make sure its WGS84 for the United States.

The right hand side of this screen allows you to configure what NMEA sentences are sent out on the bus. Under NMEA pass though put an asterisk, this will send all GPS data out onto the bus. At the top, select APA, RMB, and BWC, these settings provide the ST1000+ with route information. The rest should already be set: Target capability to Uppercase, update interval to 5s, XTE Factor to 100, and NMEA ID to EC.

Testing

Seaclear has a NMEA output monitor that lets you see the NMEA sentences that are being sent to the COM port specified in the TX1 setting. To open it, go to Tools -> System -> NMEA Output Monitor.

With the cable plugged into the computer, Open Seaclear and obtain a GPS fix. Open the NMEA output monitor. You should see the GPS data scrolling by. If not, you don’t have the TX COM port setup properly. If there is data in the output monitor, you should see the RS-232 tester pin 3 led flashing in rhythm with the data displayed. If so things are looking very good. If not, you have the wrong COM pot setup in TX1, or the cable wiring is bad somewhere before the tester.

VHF Testing

Easy, just plug in the VHF to the NMEA cable, with the above tests working properly, you should get Long/Lat coordinates displayed. If not then test the physical connection between the Rs-232 tester and the VHF jack. If this tests OK and you’re still not getting data, ensure the output monitor is sending NMEA position sentences and that your radio can decode the ones being sent. Also confirm the polarity of the NMEA bus to radio link. I had no problems with this part, it just worked, the radio was a good test for the next part, the ST1000+, which is more finicky as to the data it accepts.

ST1000+ Testing

It’s important to know that Seaclear only sends data that can be read by the AP when there is an active route AND the NMEA OUT ON option of the active route side panel is selected. So first you need to create a route in Seaclear. If you don’t know how to do this, consult the documentation, but it’s not hard.
Now you need to open a route and activate it. At this point the actual route does not mater, nor does it matter if the route is reversed properly, we just want to see if the AP is getting the data. Once the route is activated click on the NMEA OUT OFF option and make it say NMEA OUT ON. By looking at the NMEA Output monitor windows in Seaclear you should see some new data being sent.
On the ST1000+, while in standby mode, press -1 and +10 or +1 and -10 to view navigation information. The display should cycle through four screens; locked heading, distance to waypoint, bearing to waypoint, and cross track error.
You need to read the ST1000+ manual and become familiar with just how this works. I tried this with an actual route and navigated to within the .1 nm as recommended. If you don’t get all four screens of data you can try changing the settings in Seaclear, but the setting I gave worked for me. Don’t just turn everything on in Seaclear, as this may flood the bus and cause nothing to work. The bus is running at 4800 baud, which is not very fast, and if the data size exceed the update interval some data will be lost. So only send the absolute minimum NMEA sentences you need.

That’s it. If you follow this and it does not work, recheck everything, and remember, the cable is the weak link. I don’t have a lot of other systems going on, so interference is not an issue for me. My longest cable run is to the tiller at about 8 feet and I’ve had no problems.

 

[kpgraci]

That's a great accomplishment Ken! I'd like to try something like that with my ST 1000+ but I hate to part with my Standard Voyager Horizon VHF that I bought back in 1987, and my trusty hand held Garmin 12.

If you do more than sail around in circles this really becomes a must. I generally do only sail in circles, but they are large circles . If I lock onto a heading I have to watch and adjust for leeway constantly. A 10 mile straight line sail on a fixed heading will leave you way off the mark. The real beauty of using a route is the AP automatically corrects for leeway and tides - you stay solidly locked onto the route.

Of course you need steady winds for this to make sense, but since Seaclear can accept NMEA data from a wind vane, it can pass that to the AP, and the ST1000+ has a wind mode. I guess that's my next NMEA project.