Originally Posted by ON3CHD
I would be surprised if your Netbook can handle (on its internal -? is it - BT radio
that you name if I did understand correctly BT stack...) 2 port com communicating at different bds rate at the same time.
This might be the first step to check.
That part works fine. Bluetooth allows you to connect up to 7 devices simultaneously. I'm getting GPS
coordinates in at 4800 baud on COM41, and AIS
targets in at 38400 baud on COM40. For more information see the stuff I pasted below.
Originally Posted by CarCode
When I understand correctly you have two Bluetooth devices sending data to your Netbook via COM40 and COM41? (Obviously you use the Toshiba Bluetooth stack which has comport numbers in the 40th range by default).
Now you want to send data from the Netbook to your autopilot?
Which way you want to send the data to the autopilot? What is the autopilot connection you have? If the autopilot has only a serial input and your Netbook has no serial connector I guess you will need another RS232/Bluetooth Transceiver. Right?
Autopilot is NMEA 0183
@ 4800 baud. Each Bluetooth dongle is full duplex, and GPS and AIS are inbound (to OpenCPN) only. I can send data out on COM40 at 38400, or COM41 at 4800. In fact, I have already tested this using terminal emulation software
by sending commands to my GPS. Sending chartplotter
sentences out to the autopilot is very strightforward using OpenCPN, but I need to use COM41 to make it happen.
Since you both seem to want more information, here is a complete description that I posted on another forum (perhaps more than you want to know):
Over the weekend I finished installing my newly arrived Standard Horizon GX2150 VHF/DSC/AIS radio. Because of the large amount of commercial
traffic where I sail, I was very interested in getting the AIS output integrated on a chartplotter
display. I had originally purchased a Garmin
640 for this, but decided I could actually do better for much less cost with a PC-based system. My MSI Wind
netbook has an extremely bright display that is viewable in full daylight, so I bought a RAM Mount to put it on my pedestal
guard. OpenCPN's features and stability have improved greatly in the past several months, and it uses NOAA raster and vector charts
which can be downloaded for free. OpenCPN also supports AIS input and autopilot output. I wanted complete freedom to put the netbook in the cockpit
or move it into the cabin
, so I made everything transmit wirelessly to/from the netbook via Bluetooth.
In order to make for a tidy installation
(and to allow me to wire everything up in the comfort of my home), I picked up a small surface-mount network box to serve as the central interface module for the system. I daisy-chained some RJ45 receptacles to make an 8-wire bus, and terminated all the instrument wires with crimp-on RJ45 connectors. I also mounted a couple of DB9 ports in the box to attach the Bluetooth transmitters without any cumbersome cables
. The whole thing runs off a 5v supply from a USB power adapter, and draws under 270 mA @ 5v. Here's the schematic and wiring
The admiral thought the flashing lights on the interface module were "real purty". [
] It kind of reminds me of a miniature model of the International Space Station [
After crimping the RJ45 plugs onto the various components, I took it all down to the boat
, hooked it up and fired up OpenCPN on the Netbook. After configuring all the COM ports it worked perfectly, receiving all the data wirelessly through Bluetooth. Here are some screen
shots showing my boat on the hard
at West End Boat Club. With a temporary antenna
(since my mast
is down) I was able to pick up over 20 AIS targets in my vicinity, pull up preliminary info by mouse-over and detailed info by right-clicking on a target. Many of the boats were anchored. Those that were moving showed a vector that represented their estimated location in 5 minutes (user adjustable). The yellow boat(s) are ones the meet some user-adjustable criterion for collision
threat. (Still need to get familiar with the particulars.) When my boat is underway it will estimate distance and time of closest point of approach:
In addition to achieving a new height in geek factor, this will be a very useful safety
feature in staying out of the way of shipping
traffic in our busy river.