Connecting to your marine instruments

The connection to your marine instruments is done through WiFi.

Most modern multifunction instrument can publish its data in NMEA 0183 format over a WiFi network. If this is your setup, simply connect to that network.

Otherwise, you will have to connect your marine instruments to a wifi NMEA multiplexer. This is often a more flexible solution. You can wire multiple devices to the multiplexer that will publish in wifi a single NMEA feed. A fixed GPS, a navigation system, an AIS receiver or transponder can be connected at the same time.

We recommend the following multiplexers:

  • the Digital Yacht multiplexers like the Smart WLN10 or the new Smart WLN30. These multiplexers have a Web interface that is used to easily the initial configuration of the devices. They supports the UDP and TCP protocols and 7 devices can receive data at the same time.
  • If you are looking for all in one device which acts as a AIS transponder and a multiplexer, then go for the Digital Yacht AIT3000 or the new AIT5000. The new AIT5000  is a Class B+ AIS Transponder with a 5W power output that utilises SOTDMA format transmissions for an increased safety at sea.
  • the MiniPlex-3Wi from ShipModul (or the old model MiniPlex-2Wi)

If you own a GMN Optimizer, you can connect your system to the USB input of the Optimizer. After configuration, the Optimizer will broadcast the NMEA data on its wireless network. You will, however be limited to a single NMEA source. To connect several sources to the Optimizer, you will have to go through a USB multiplexer such as MiniPlex Lite from ShipModul.

Once the wireless network ready, go to the wifi settings of your Android device to connect to it.

Then in SailGrib WR, from the Settings menu, go to NMEA Settings

  • Enable the NMEA and AIS Connection
  • Select your NMEA Source. We have pre-set the following sources:
    • AIS-Share: an AIS Android app, we will come back to it in the AIS chapter.
    • Digital Yacht
    • DK Innovation
    • GMN Optimizer
    • NKE : to connect to a NKE wifi box
    • Miniplex de ShipModul
    • teamSurv
    • vYacht
    • Vesper Marine
    • dAISy
    • Log - for reading NMEA log files. We will come back to this later.
    • Other, for manually setting the IP address of the multiplexer and the port on which the data are released.
  • Select the data transmission protocol, TCP or UDP. The UDP protocol is more flexible, there is no connection between the multiplexer and the app. The multiplexer simply broadcasts the data to a port. The application listens on this port. You can have as many devices as you want to listen to the multiplexer. A bad reception does not delay the data.
    In TCP mode, each multiplexer will limit the number of connections (only 1 for Miniplex 3). A poor connection will delay the data. In addition, if a connection is not properly closed, the multiplexer must be restarted.
  • Choose if you want to use the GPS from the NMEA feed. You will be able to switch off the internal GPS your Android device which will significantly reduce power consumption.
  • Choose whether you want to overwrite the speed and heading data of your instruments (CTW and STW) with those of your GPS (COG and SOG). This option is most often used if the speed sensor is dirty, or broken.
  • Choose if you want to save daily Log files of your NMEA data. These files are saved in the sailgrib/nmea directory. Depending on the NMEA output, they can be quite heavy, remember to delete them from time to time.
  • You can Start the NMEA service from this screen to verify that you are receiving data. Statistics on the data feed and the last sentence received are displayed.

Maintain your Internet connection
If your Android device is connected to the Internet by 4G, you will probably want to keep the 4G Internet connection while receiving data on board via WiFi from the multiplexer. It is possible. This requires that the multiplexer has not defined a default route (default Gateway) in 0.0.0.0.0. This is the case for recent multiplexers (Digital Yacht, Miniplex 3 with the latest firmware). If this is not the case for your multiplexer, you will need to establish a connection sharing from your mobile device and connect the multiplexer in client mode to your mobile’s WiFi. Refer to your multiplexer’s manual for instructions.

If you have connection problems, please refer to the dedicated FAQ.

Last updated: 5 April 2018