How to get wifi AIS
Q
My son and I bought a Matsutec HP-528A AIS transmitter/receiver which we are very happy with but we have a query regarding its data capability.
The back of the unit has 9-pin data plug/socket (the third from the right), while the other three connections are for the power supply and the two aerials which we’re not concerned with here.
This unit is fixed in the main cabin right in front of the helm position which is just fine if steering from the inside of the boat.
But we’d like to repeat the data on the screen to the flybridge and it’s not feasible to move the whole unit and its inputs to the bridge.
Apparently the data connection is a basic NMEA (I assume 0183) and uses the same or similar protocol as the RS232 and RS422 series bus. which is mentioned in the handbook.
We currently use an iPad on the bridge which is fitted with a dongle for the GPS data and using a navigation app called iSailor.
So the question is how do we get the AIS display onto the iPad (the iPad uses a lightning connection with the dongle)? William Harris, by email
ANDY HAINES REPLIES: This AIS is not a product I know – it appears to be a grey import.
Grey imports – from places like ebay or Amazon – are a bane to the marine electronics industry: apart from leaving the customer without backup and warranty, it has also taken a sale away from a UK supplier. I’m retired now, but this has happened to me many times in the past. I usually start by reading the riot act, then relent and help the guy out because I’m a softie and feel for the customer’s plight. But, that depended very much on how the customer approached me/us in the first place. Someone who comes in cap in hand realising they probably made an unwise purchasing decision is more likely to get help than someone stamping their feet and demanding help.
Having said all that, this actually looks a nice, robust unit, very Furuno-ish in style. If I was looking at the front without any further information I’d have said it was a Furuno!
Either way, it does appear to support NMEA 0183 v2, which should be fine for sending AIS data onwards, but it does need to be at 38,400 Baud Rate (not 4,800 which generally isn’t used for AIS). So the you need to sure this AIS unit sends NMEA data at 38,400 Baud Rate.
If you had a chartplotter, or second plotter, on the flybridge that had an NMEA 0183 input, it would be easy enough to hard wire the NMEA output from the AIS to the NMEA input of the plotter.
However, with a tablet, we need to change the format from hard wired to wifi. There are several devices available for this, but I think I’d opt for the Digital Yacht WLN10 or WLN30 (preferably the latter). Basically, you take your NMEA output from your AIS (at 38,400 Baud Rate) and hard wire it to the WLN10/30, this then converts it to wifi which will then wirelessly link it to your tablet. The WLN10 only has one NMEA input, so you can only link in one device (such as your AIS), but in this case that may well be sufficient.
The WLN30 has three NMEA inputs and will multiplex all the inputs together and then send the whole lot in one data string via wifi to your tablet. This would allow you to, say, take one input from a GPS for ‘position’ data, one input from your AIS for ‘AIS’ data and another from a third device/s such as an instrument system (this would then allow ‘instrument’ data such as boat speed, depth etc onto the tablet as well).
The WLN30 is a bit more expensive, but neither of these products are that expensive anyway, so I’d advise investing in the better of the two, then if something crops up in the future you’d be able to interface that as well (as long as that device had an NMEA 0183 output).
Interestingly,you’ll probably be able to dump your iPad GPS dongle as I suspect the NMEA data from your AIS will probably send position data as well as AIS data.