Question for Globalsat BU-353 users

[RhythmDoctor]

For all of you out there who have the Globalsat BU-353 (or other USB GPS pucks) connected to your computers, what do you do to interface GPS with your DSC radio? It would seem to me to be much safer to instead get a true serial NMEA GPS puck and wire it directly to your radio, then split the pair of signal wires off that to your computer to a serial port (if you have one) or a serial-USB converter.

Doing it this way, you would ALWAYS have the GPS going to your radio - even if your computer dies, which would be much safer since you need the GPS feed for the distress button (and other DSC features) to work.

[CarinaPDX]

Yes, you have it. I only use the USB pucks with my laptop. The tablet has internal GPS. For the DSC radios and modem I use an NMEA 0183 GPS, specifically the Globalsat MR-350. I use another for the GPS input to my Garmin chartplotter. They are about $60-70. Lots of redundancy...

Greg

[CarinaPDX]

Ooops- skimmed your post too fast. While you could share that way it is silly when considering the low price of the BU-353. I wouldn't do it as it adds failure modes. Just buy the extra one.

Greg

[rgleason]

Have same g star puck wired to vhf/dsc standard horizon through their ps2 extension (with own 5 volt power).

Can unplug and connect to laptop using ps2 to usb cable.

Have to remember to set baud rate slower for vhf or it does not work (using sirf software (forgot baud but I think it is 4800 see vhf specs)

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[jeroenimo]

I have successful attached this one to a VHF to update its position.

You need to hack a Ps2 cable open and connect the right wires to the VHF, give it 5V power and away you go!

The wiring info can be found here

[CarinaPDX]

Some additional comments:

The PS/2 connectors on some GPS pucks are commonly used so if you don't mind the additional failure risk you might track down the mating connector instead of cutting it off. FWIW I cut it off...

I use standard cigarette lighter USB power supplies to obtain the necessary 5V.

Be sure to purchase the SirfStar III version of the puck - it is the most sensitive and can usually be used below decks. The SirfStar IV is intended for embedded applications (think smart phones and tablets) and is not as sensitive (different priorities).

Greg

[jeroenimo]

Agreed on the sirfstar III vs IV! So get the cheapest one on dx.com

And a cheap old ps2 cable.

For power supply I have used this one:

http://dx.com/p/m1201-dc-3-40v-to-1-...4#.UuFoj3jtTCQ

[CarinaPDX]

Originally Posted by jeroenimo

For power supply I have used this one:

M1201 DC 3~40V to 1.25~35V Adjustable Step-Down Converter Voltage Regulator - Blue - Free Shipping - DealExtreme

Wow, I like that - at least for other applications. Cheap, powerful, and flexible. But requires adjustment, which in turn requires a reasonably accurate DVM, so trivial for some of us but a pain for others. I have found the similarly cheap cigarette lighter USB chargers to be regulated very precisely and stable at 5.00v to within a count or two.

Greg

[rgleason]

Found a well mounted power supply with all heat sink that accepted something like 16 - 12 volts dc and output 5. Small enough to attach to vhf connecting wire with male ps2.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[RhythmDoctor]

My question was one of curiosity for those who have USB pucks. I was not actually seeking advice on what I should do, because I have already hardwired a serial puck to my VHF radio. My main point is that feeding GPS to the radio is so important that you should not rely on having a computer running. If the computer crashes, or the laptop battery dies, then you lose your GPS feed to your radio. The radio does not need any route information, XTE, or anything like that. It just needs location data, so a simple puck is adequate and more reliable than a chartplotter.

In my case, I went with a Garmin 18x LVC. It needs 12 volts, so I tapped directly into the radio's electrical feed. If the radio's circuit breaker is on, then the puck gets power.

Originally Posted by CarinaPDX

...While you could share that way it is silly when considering the low price of the BU-353. I wouldn't do it as it adds failure modes. Just buy the extra one...

Although I'm all for redundancy, I think there is some added safety in tapping into the GPS puck's feed to the VHF and monitoring it using OpenCPN. That way, you can verify that the puck is working (red ownship icon) and sending a reasonably accurate fix (location is not halfway across the globe, and satellite bars are green in OpenCPN). You can even run another program like PolarCOM for more in-depth monitoring of the puck's satellite status.

In my case, I went one step further. Instead of running a hardwire to my computer, I attached a serial-Bluetooth converter to the NMEA feed, and I can pick up the GPS feed wirelessly anywhere on the boat using any one of a variety of laptops and tablets. I was so happy with it that I added a second serial-Bluetooth converter to broadcast AIS data from my GX2150 radio. A second BT transmitter was cheaper than buying a multiplexer. Both serial-BT converters run off of 5v DC, and I tapped an automotive 12v adapter with USB insert to provide the step-down voltage for them.

As for redundancy, I also have a Garmin handheld, my Android phone (running Marine Navigator with NOAA charts loaded), and an iPad running Bluecharts (which I don't like nearly as much as OpenCPN). And the new Windows 8.1 tablet that I bought for my new OpenCPN display also has an internal GPS, so that will add yet another level of redundancy if the others fail.

Occasionally, I even look up to see where I am.

The main point of my post was to encourage people to get a serial puck attached to their VHF, so the "distress" button will work in an emergency. A USB puck hooked up to a computer shoudl be in addition to the hardwired puck, not instead of it.

[atoll]

Originally Posted by RhythmDoctor

My question was one of curiosity for those who have USB pucks. I was not actually seeking advice on what I should do, because I have already hardwired a serial puck to my VHF radio. My main point is that feeding GPS to the radio is so important that you should not rely on having a computer running. If the computer crashes, or the laptop battery dies, then you lose your GPS feed to your radio. The radio does not need any route information, XTE, or anything like that. It just needs location data, so a simple puck is adequate and more reliable than a chartplotter.

In my case, I went with a Garmin 18x LVC. It needs 12 volts, so I tapped directly into the radio's electrical feed. If the radio's circuit breaker is on, then the puck gets power.


Although I'm all for redundancy, I think there is some added safety in tapping into the GPS puck's feed to the VHF and monitoring it using OpenCPN. That way, you can verify that the puck is working (red ownship icon) and sending a reasonably accurate fix (location is not halfway across the globe, and satellite bars are green in OpenCPN). You can even run another program like PolarCOM for more in-depth monitoring of the puck's satellite status.

In my case, I went one step further. Instead of running a hardwire to my computer, I attached a Bluetooth transmitter to the NMEA feed, and I can pick up the GPS feed wirelessly anywhere on the boat using any one of a variety of laptops and tablets. I was so happy with it that I added a second Bluetooth transmitter to broadcast AIS data from my GX2150 radio. A second BT transmitter was cheaper than buying a multiplexer.

As for redundancy, I also have a Garmin handheld, my Android phone (running Marine Navigator with NOAA charts loaded), and an iPad running Bluecharts (which I don't like nearly as much as OpenCPN). And the new Windows 8.1 tablet that I bought for my new OpenCPN display also has an internal GPS, so that will add yet another level of redundancy if the others fail.

Occasionally, I even look up to see where I am.

The main point of my post was to encourage people to get a serial puck attached to their VHF, so the "distress" button will work in an emergency. A USB puck hooked up to a computer shoudl be in addition to the hardwired puck, not instead of it.

ideally the next generation of gmdss vhf radios will come complete with a usb port,just for the gps puck interface,as do car stereos for an ipod!

i had this problem recently,and ended up buying a stand alone gps,with an external antenna. A to feed nmea to the vhf,and B as a back up for a laptop running open cpn!

[CarinaPDX]

I agree that a GPS puck should be permanently attached to the DSC gear. It is not necessary to have a separate display IMHO. I have a GX2360S so I am guessing that our displays are somewhat similar. There is a satellite icon that shows in the upper right corner when the GPS signal is received. It is also easy to see the current nav data on the display, although there can be a delay in warning if the GPS cuts off (not so with the icon).

Your bluetooth approach is a great way to avoid stringing wires around. I haven't had a problem with the 353 cable but of course the radio waves are tidier. I don't really use my laptop that much for navigating underway - it is not waterproof so I keep away from it with wet hands and clothing. My Furuno chartplotter now has a dedicated GPS puck, in part because I didn't want to stretch wires back to the radio. Again, the bluetooth system would work well. My redundancy for the chartplotter GPS is the GPS output of the Class B AIS. The tablet is a recent toy, which is great for the US with the free NOAA chart program for Android.

Sometimes I don't look up often enough but I'm not going to tell tales on myself...

Greg

[Jetx]

Hi RythmDoctor. Apologies for reviving this old thread, but your comment caught my attention...

Originally Posted by RhythmDoctor

In my case, I went with a Garmin 18x LVC. It needs 12 volts, so I tapped directly into the radio's electrical feed. If the radio's circuit breaker is on, then the puck gets power.

I like the idea of hooking up a GPS puck to the VHS without the 12v-to-5v converter that's required with the Globalstar devices (just another potential failure point), so I was just about to go out and buy one of these babies! But then I went and looked at Garmin's specs for the 18x LVC, just to be sure I could figure out how to hook it up, and on page 5, it says that it needs 5 volts. Are the specs wrong, or does the device tolerate 12V despite the "specified" 5V input voltage?

Any other special steps you had to take, or any configuration changes needed via Garmin's software utility, to make this work?

Much thanks!

Jeff