GPS communication to VHF radio

[pbutler]

Hellosailor got it right. The solution is a dedicated GPS sending NMEA0183 data to the VHF. Run them off the same power switch and they'll act as one unit, independent of other system failures. I did this and it's just a matter of figuring out which wires are NMEA out on the GPS and which are NMEA in.

<rant>
On a related note, does anyone else find it crazy that after a decade of being *required* to put DSC in radios, VHF manufacturers don't provide GPS chipsets and antenna connections built into all their equipment? What's the thinking there? NMEA0183 wiring is complicated, messy and failure-prone (in most homebrew installs). Heck, I'm an engineer and it still took me an hour to figure out how to wire my Garmin GPS to my Standard Horizon fixed-mount VHF.

I'm sure there are a bunch of folks just like the OP who are thinking of getting a GPS signal to their VHF via some complicated, failure-prone system. That's nuts. When I push that red button, I want a DSC mayday with lat/long sent *right now*!

I've got a Standard Horizon 850 handheld with built-in GPS. It's wonderful and *just works*. If they can do it in a frigging handheld, what's stopping them from doing it in every other radio. It's not like the chips cost money--they're in just about every cell phone out there. Is there some regulatory or liability issue I'm unaware of here?
</rant>

[hellosailor]

"It's not like the chips cost money--they're in just about every cell phone out there."
Actually, full GPS chips are NOT in most cell phones. MOST cell phones have what is called "A-GPS" assisted GPS. The cell phone can receive GPS signals--but it cannot process them, all it can do is trasmit the raw data to the cell phone system, where it is processed into a locaiton and then returned to the phone. This is done by the major cell phone carriers in the US (Sprint/Nextel being the rare exception) in order to force phone users into paying for data services and monthly locator service plans.

Every chip costs money, Every square mm on the circuit board costs money. And every time a feature is added to a radio the radio has to go back to the FCC to be recertified, at a 5-figure cost IIRC. And then a further cost for every compliance rating it needs, i.e. EU, Canada, Japan, etc.

Our entire system is set up to cripple innovation and reward plodding, look at where it has taken us.

[richardhula]

Originally Posted by hellosailor

"It's not like the chips cost money--they're in just about every cell phone out there."
Actually, full GPS chips are NOT in most cell phones. MOST cell phones have what is called "A-GPS" assisted GPS. The cell phone can receive GPS signals--but it cannot process them, all it can do is trasmit the raw data to the cell phone system, where it is processed into a locaiton and then returned to the phone. This is done by the major cell phone carriers in the US (Sprint/Nextel being the rare exception) in order to force phone users into paying for data services and monthly locator service plans.

Every chip costs money, Every square mm on the circuit board costs money. And every time a feature is added to a radio the radio has to go back to the FCC to be recertified, at a 5-figure cost IIRC. And then a further cost for every compliance rating it needs, i.e. EU, Canada, Japan, etc.

Our entire system is set up to cripple innovation and reward plodding, look at where it has taken us.

I seem to remember reading that cell-phones can get a pretty good fix without any help from GPS just by triangulating from the known positions of the towers there connected to. Some phone providers offered a location service based on this - great for checking the whereabouts of your kids

Regarding GPS in DSC radio's. Sure great idea but what about the antenna? A built-in one may work inside the boat, but what if its a steel boat. OK so they put an external antenna socket on the back. How many users are going to the trouble of installing one given the extra cost, cable runs, attachments etc., when you can buy a stand-alone USB GPS receiver for $30?

Then as you mention, how are the manufacturers going to get certification unless it's 100% workable? Remember we are talking about equipment responsible for saving lives.

For the record Comar had to build in a GPS with external antenna socket to get certification on their CSB200 AIS transponder.

Regards

[hellosailor]

The cell phones actually don't get a fix without GPS. The cell phone system gets the fix on the phone by timing the signals from the phone to multiple towers, using enhanced software in the cell phone system. Something like 100 yards if they can get three towers, sometimes more like 1/2 mile to several miles if they can't. At sea? nothing without both a GPS signal AND the assistance of the towers, for the A-GPS phones.

VHF certification would be no problem--they GPS portion doesn't need to be active during class type certification, it is just the new "radio" that has to be tested for conformation. So with or without the GPS function, the radio would be retested and passed as long as the radio worked.

Good point about the futility of building in a GPS when it might be in a steel hull, but the commodity-grade GPS chipsets used now (3rd and 4th generation) work very well under the deck of a typical recreational boat. Steel hulls are still found mainly in working boats--where there's enough budget to wire up an outside GPS, and commercial regulations to encourage the owners.

[pbutler]

OK, point taken about the chip cost/recert issue. There's a real expense there. But, again, they've had a *decade* to do this. Is Standard Horizon (just to pick an example) currently selling *any* 10-year old radios?

I'm also fully willing to admit that this is a chicken/egg issue: I have multiple friends with boats and exactly one of them has an MMSI number (without which this whole thread is moot) and has bothered to hook his VHF to a GPS.

Whose fault is this? One could argue that, "if you build it they will come." In other words, if every radio included a gps antenna (or remote gps with a plug-and-play connection to the radio--same thing), and clear instructions for obtaining an MMSI number, we'd have a great many more people doing just that. One could just as easily argue that the demand for this is so low that it makes no sense for manufacturers to do anything at all.

It's not like eveyone hasn't been thinking about these problems for quite some time:

http://www.navcen.uscg.gov/MARCOMMS/gmdss/dsc.htm

shows just how long we've had exactly the same problems we have right now.

The point of my previous post was that the radio manufacturers have by far the greatest ability to drive progress here, and by all indications they've been dragged kicking and screaming into it. The hardware and software interfaces for anything DSC are atrocious, and they're not even shipping the required parts. Even a minimal effort on their part could result in a huge improvement in adoption here.

From the USCG document linked to above:

Although NMEA has no standard for the type of connector used, many if not most DSC and GPS receiver manufactures use bare wire connections. These wires are simply connected between the radio and the GPS by twisting the wires (some people solder) and tape (some people use waterproof heat shrink tubing).

Yeah, that's going to turn out just fine.

[hellosailor]

Well, in terms of standard connections I would argue that the industry (the world) simply hasn't matured enough on that yet. What IS coming down the line, is the USB bus and USB connections, as demonstrated by the cell phone manufacturer's who have recently passed a standard to use the "miniUSB" connection for ALL CELL PHONE CHARGERS starting in 2010, IIRC.

Standards don't come easy. The only reason you have standard 12-volt electrical systems is (say THANK YOU SAILOR) that the US Navy wrote a purchasing requirement in the 40's saying "If you want to sell us a vehicle, it will have a 12-volt negative ground electrical system, period."

Industry usually doesn't innovate, they need to see the carrot AND the stick.

Which comes back to cell phones and miniUSB...the chargers, the wall-warts, have to be UL/CE/etc certified (five figure$ plus to test) so there's an incentive to have standard chargers around. Sadly, USB devices still require host computers, they can't plug into each other the way NMEA/RS-232 devices can YET. The new host chips that contain enough brains to make this possible at a low cost ($5-ish, like Bluetooth radios) are already on the market, and should ramp down and start showing up in more gizmos in another two or three years.

Ten or twenty years to implement a standard and connectivity may seem like forever, but when cell phones had been around for ten years, they still cost over a dollar a minute to use and they sure didn't fit in everyone's pocket.<G>

[pbutler]

You're right about how long standards and interoperability take to take hold in a marketplace, but that's a red herring. We're not talking about interoperability here. We're talking about building well-defined functionality into a single device.

Standard Horizon makes radios. They also make GPS equipment. More importantly, I'm sure there are half a dozen OEMs out there who will happily supply Standard Horizon with GPS equipment with whatever connector they want. Interoperability never enters into it.

The current situation is like selling cars without brakes and then telling the buyers, "you can drive this car just fine, but it's not going to stop until you bolt on some aftermarket brakes. We've supplied a standard brake mount--get out your wrenches and have at it." Why not just build brakes into the car in the first place?

Normally the market is supposed to take care of this stuff. I guess I'm just confused about why it hasn't in this case.

[hellosailor]

"Why not just build brakes into the car in the first place?"
You know how long it took before what kind of brakes were standard on cars? Much less the disk brakes we take for granted today?
Heaters, headlights, turn signals, windshield wipers...all totally non-standard options for many long years. Case made?

[pbutler]

You know how long it took before what kind of brakes were standard on cars?

But we're not talking about standardization here. We're talking about building cars with brakes. To torture this analogy futher, GM doesn't have to worry about how Ford builds brakes. GM's brakes just have to work on GM's cars.

If a manufacturer's goal is to get *their* GPS data into *their* VHF, their choices are wide open--they can worry about standards or not--and they do it all the time; Standard Horizon uses a different microphone connector than Icon or Garmin, because they're not worried about microphone interoperability.

Why don't they have the incentive to do the same thing with GPS data--which they *know* their radios are going to need to operate correctly?

[rodney_k]

Originally Posted by pbutler

Standard Horizon makes radios. They also make GPS equipment. More importantly, I'm sure there are half a dozen OEMs out there who will happily supply Standard Horizon with GPS equipment with whatever connector they want. Interoperability never enters into it.

FYI, Standard Horizon makes a couple of chartplotters with an integrated class D DSC VHF, the CPV 350 and CPV 550. I have the 350 aboard my boat, and it is really nice. DSC functions right out of the box. Program your MMSI and you are ready to go. These chartplotters can also handle an optional depth sounder module & interface to certain Sitex radars too.

Some might complain that you have to have the chartplotter powered up to use the radio and that the combined box becomes a single point of failure but I'll take that chance. I have a second GPS\chartplotter & VHF at the helm.

[Heikki]

Originally Posted by pbutler

I'm also fully willing to admit that this is a chicken/egg issue: I have multiple friends with boats and exactly one of them has an MMSI number (without which this whole thread is moot) and has bothered to hook his VHF to a GPS.

This must be a cultural issue. Up here, all people I know - excluding the ones that sail on lakes only - have their VHF with DSC and GPS. Maybe this is due to the local press heavily promoting the upgraded technology - or maybe we are just technology crazy nation (like we are told to be). Another reason may be the wide availability of public SSB courses that all pretty much assume that you have your VHF with DSC and GPS. After such a course, one would feel kind of very outdated, maybe even unsafe, with an old VHF only. Sure enough, my sample might be very biased. I do not know everyone.

Personally speaking, sailing is expensive anyway. Why to save on this issue that can well be a matter of life or death?

[hellosailor]

Could be because the waters off Finnland are not as warm and balmy as much of those off the US coasts, so a fast and precise SAR response is a more serious matter?