Another post to while away some winter hours, and incidentally to keep the boats documentation up to date.
I use an iPhone and iPad, everything here should also apply to Android devices but I am not familiar with them.
I have had a powered USB hub on the boat from the beginning, why will become apparent, the reason for the upgrade is my increased use of the PC on the internet. For reasons of economy I have generally restricted my internet use to the unlimited (but "throttled") data only sim in my iPad occasionally using the laptop through its wi-fi hot spot, this year with prices dropping I put a meaningful amount of data onto the iPhone account (and that is from now also unlimited), the problem then became the wi-fi connection drooping when briefly inactive which was a pain in the neck.
To solve that through 2024 I tethered the laptop to the phone using a USB cable which works well and also gives easier data sharing between the laptop, phone and chart plotter, the problem is then remembering to reconnect the phone to its USB charging point or, without power from the PC, the battery will run down, that only happened once but that is one time to many so to sort that the phone needs to connect to an always on powered USB hub that can also provide charging.
I was also using an unpowered hub daisy chained to the 4 port powered one and there were lots of wires in inconvenient places. It was time to upgrade.
Installation is all straight forward although choosing and getting power to the hub needs some thought and research, see below.
 |
| Click to view. |
Connections and Services
For a lot more detail on integration see SV Sancerre: Wi-Fi networking and application integration on Sancerre remembering this was written before the upgrade to a 7 port device, tethering the phone etc.
iPhone (or any smart phone)
- Connects the PC to the internet when a 3 or 4G connection is available.
- Using Garmin Active Captain and wi-fi, transfers routes from the navigation software plus software updates and community notes from Garmin to the plotter.
- Smart notifications such as SMS texts, Facebook notifications, etc. are transferred to the plotter by Bluetooth.
AIS
The Garmin AIS unit only puts AIS information onto the NMEA 2000 network and keeps its GPS data to itself which is annoying as with its external antenna it has the most reliable and most accurate GPS position on the boat (although the internal aerial in the plotter has not lost a signal yet).
However there is a USB port for set up and diagnostics and when I installed it I suspected that it would use standard NMEA 0183 protocols; why invent new ones when standard ones exist and you already have code for dealing with them? And so it proved, so the USB cable is permanently connected to the hub, the Garmin USB driver presents a logical COM port to applications and those that are capable can use the differential GPS / EGNOS fix (& Glonass), I use mainly use SeaPro 3000 and Memory-Map but is can also be useful for Google Earth and other applications.
GPS
As backup I have an old USB GPS device (they are less than £10 with support for GPS, GLONASS, WAAS, EGNOS, etc.), either would allow the PC systems to take over position fixing if the plotter and NMEA2000 network failed. It is also occasionally useful when switching between SeaPro and Memory-Map, perhaps to use the Antares charts or to check a route on the standard Admiralty raster charts. The AIS com port can not be shared between applications and even if you close one application down the PC is likely to think the port is still potentially active and the newly launched software gives an error.
I set Memory-map to use the USB GPS and SeaPro to use the AIS output and I can then have both active at the same time or switch between them without problems. In the event of a failure I can easily change the configuration to allow SeaPro to use the dongle.
GND
 |
Some of the many re-sizable windows available
on a connected PC with Nexus. They can be moved
around to fit with or on top of other windows. |
Is a bridge between the wind instruments and NMEA200 but also runs as a server for Nexus software providing most of the information from the NMEA 2000 network down a USB connection, unfortunately that is not usable by SeaPro or Memory-Map but free software allows you to display it on the PC. I can't remember when I last used it but it is free so it might as well be connected.
NAVTEX
I rarely use it as the met office forecasts are readily available on their website and navigation warnings from the Admiralty website and they are also broadcast by the coastguard but venturing further afield it is a useful backup or replacement for IridiumGo (which does not carry the nav warnings).
USB-3 connection
I use this to connect various ancillaries such as a card reader (not included on my new laptop) or DVD or to plug in an iPad. This is also a powered port so will do a better job of supporting an iPad.
USB-2 connection
The only difference to the USB-3 connection is the spec of the cable but the lower speed is not an issue as it is normally used for the security dongle required with SeaPro.
Power
This might be the tricky bit. Powered hubs are intended to run from the mains, using an inverter, even if you have one installed, does not make a lot of sense - converting 12V DC to 240V AC and back to whatever DC voltage the hub uses.
However all is not lost, over the years makers have been standardising many PC related items to run off of 5V DC as used by USB devices, even my latest lap top when on mains uses a 3 Amp 5V supply connected to the PC by a USB-C plug (for some reason the car 12V lead and converter uses a different socket).
My original 4 port hub came with a 240V 13Amp USB charging plug and a USB-A to centre pin lead, I just replaced the 13A plug with an off the shelf 12V to USB socket available from the chandlers and elsewhere.
 |
The 7 port powered hub. Preferred to others as it is small and does
not have unwanted switches or lights. It is USB-3 so fast and
2 ports will provide additional power with automatic detection.
The voltage is marked by the socket on the end. |
This time I could not find one like that and online suppliers don't seem to specify the intermediate voltage of there units, but if they have a detachable lead the voltage should be noted beside the socket and it should also be on the power supply; usually in almost microscopic lettering with the rest of the spec. So the trick is to expand photos to read the info from there. I found that the Kingston units were definitely 5V, the power cable is captive to the power supply so in a worst case I would cut the cable and splice it to a USB cable, fabricate from scratch (but there is an easier route, see below) or look for one, but the cable on my old hub does the trick.
 |
12V to 5.1V step down unit with
sensor for fast charge. |
Using an off the shelf USB socket for the power source does have a down side, all of the ones I have seen working from 12 volts deliver 2 Amps, useable but not that good for recharging a phone or iPad and could be marginal if an iPad was connected as well. The solution is a step down unit, these are readily available on eBay and elsewhere, most deliver 3 Amps for 15 Watts nominal costing £5.89 including postage and is available with USB or bare wire output that would be easy to connect to the power lead that comes with a hub. I found one that delivers 5 Amps through up to 4 female USB-a sockets @ £6.91.
I prefer things fused and switched so the step down unit has both, getting power from the low power switched bus behind the electrical panel. It will normally be left switched on at the panel and will go off when the master switch is off, but if I am a long time at anchor (quite likely) and short of power (unlikely) I can switch it off.
