How to output GPS signal to a DSC radio?

[rgleason]

For my gps puck to Standard Quest+ VHF/DSC radio, I read the specs, powered the puck with a small buck converter from ebay and just connected the wires properly, after putting it into serial mode on the computer. Its been running like that for probably 5 years. I did make a thread about it with photos etc.
I didn't worry to much about proper connectors since it is permanent and dedicated.

[CarinaPDX]

Originally Posted by sdowney717

What device would be used to share this GPS data to many devices?
And we really don't know if the rs422 converter might have fixed the issue?

As another poster said, the GPS output can feed up to 4 listeners at once, in parallel. That is, the 4 RX+ are tied together and the 4 RX- are tied together.

The RS-422 converter would not have helped your problem; a firmware upgrade might.

Greg

[sdowney717]

Originally Posted by CarinaPDX

As another poster said, the GPS output can feed up to 4 listeners at once, in parallel. That is, the 4 RX+ are tied together and the 4 RX- are tied together.

The RS-422 converter would not have helped your problem; a firmware upgrade might.

Greg

Ok, I did decide to also buy an rs232 to rs485 converter very cheap on Aliexpress was $3. I may try it and see if it works like it should.
I was reading about them and it seems if your not sending data back into the converter, it just works as an rs422 would. The one I got is here

https://www.aliexpress.com/item/3259...c8ef4c4dvNNXfx

[Moo]

Originally Posted by sdowney717

You mean just splice them all together?
Do these other NMEA devices require rs232, rs422 or can they use either ?
How about take a rs232 GPS, convert the signal to rs422, then connect it to 4 other listeners?

Yes using a suitable connector block you simply connect them together.


I'll try to do a drawing later if I get time.


The talker device will only be one of those standards so it depends on the receivers.



You could use a converter as buffer but there are special devices. There is rarely need to feed more than four listeners.



Something like the shipmodule miniplex series does a superb job of everything that you are trying to do, but perhaps outside of your price range. In this game you get what you pay for (usually)

[rgleason]

4 Nmea 0183 Listeners can be joined to one talker.
however joining multiple talkers requires a multiplexer.
It makes sense.

[sdowney717]

Originally Posted by Moo

Yes using a suitable connector block you simply connect them together.


I'll try to do a drawing later if I get time.


The talker device will only be one of those standards so it depends on the receivers.



You could use a converter as buffer but there are special devices. There is rarely need to feed more than four listeners.



Something like the shipmodule miniplex series does a superb job of everything that you are trying to do, but perhaps outside of your price range. In this game you get what you pay for (usually)

Absolutely, and at the low price for a marine GPS or a puck, you can have multiple GPS. It may be a good thing to have a dedicated GPS for a radio that is not shared to other things, cause what if the other devices wires shorted out the GPS signal n some kind of emergency situation, then your DSC call wont go out.

I have a second usb GPS puck device plugged into the usb 3.0 hub at the helm which goes into a PC 20 feet away that sends an HDMI video signal back to the LCD monitor. I use OpenCpn on Linux Mint. It's been flawlessly working for over a year and it was $7 from Aliexpress.
https://www.aliexpress.com/item/3280...28014c4dCZrJTH

My Boat is a 37 foot salon cruiser powerboat, I have plenty of interior space at the lower helm chart table to hold the monitor, hub, mouse, keyboard, etc....

Are there other devices than can use a usb networked GPS like that as in share it by plugging into the usb hub?
And does a USB GPS when a USB hub is powered on, does it activate without the PC starting up?

[Moo]

Originally Posted by sdowney717

Absolutely, and at the low price for a marine GPS or a puck, you can have multiple GPS. It may be a good thing to have a dedicated GPS for a radio that is not shared to other things, cause what if the other devices wires shorted out the GPS signal n some kind of emergency situation, then your DSC call wont go out.

I have a second usb GPS puck device plugged into the usb 3.0 hub at the helm which goes into a PC 20 feet away that sends an HDMI video signal back to the LCD monitor. I use OpenCpn on Linux Mint. It's been flawlessly working for over a year and it was $7 from Aliexpress.
https://www.aliexpress.com/item/3280...28014c4dCZrJTH

My Boat is a 37 foot salon cruiser powerboat, I have plenty of interior space at the lower helm chart table to hold the monitor, hub, mouse, keyboard, etc....

Are there other devices than can use a usb networked GPS like that as in share it by plugging into the usb hub?
And does a USB GPS when a USB hub is powered on, does it activate without the PC starting up?

Sorry no diagram yet.. rug rat keeps crawling up my leg...



Yes and no to your cheap multiple devices idea. The more expensive devices are going to be a lot more robust with optoisolators (very basically a device that uses light to transmit the signals thereby stopping potentially damaging voltage getting into it) and crowbar circuits etc. All of that means that they are unlikely to be damaged by external faults, transmissions from your SSB, lightening strikes etc..



In my opinion better to have a robust network build from good basic components that a lot of chap crap. You only need one spare GPS and sextant. No doubt you have phones and tablets with GPS inside... there is no shortage of backups aboard these days. Go with quality every time, or build your own to the same specification.

[CarinaPDX]

I agree that the RS-485 adapter should work but with so many others available that specify RS-422 I don't see the point in taking a chance. I don't claim any particular expertise here. Let us know how it works for you (although I guess there is likely to be no difference in behavior from what you now have).

USB hubs don't work like that. They are designed to connect multiple peripherals to a computer, as if each had its own direct connection. One peripheral doesn't see another's communication, and there is only one computer. If a hub is externally powered (i.e. not just from the computer's USB port) it will power the peripherals even if the computer is off.

Sometimes there are devices that can use GPS data through an NMEA 0183 port which aren't obvious. My Furuno NAVTEX uses the position to select the nearest transmitter station, although I prefer to manually select it.

Greg

[sdowney717]

Originally Posted by CarinaPDX

I agree that the RS-485 adapter should work but with so many others available that specify RS-422 I don't see the point in taking a chance. I don't claim any particular expertise here. Let us know how it works for you (although I guess there is likely to be no difference in behavior from what you now have).

USB hubs don't work like that. They are designed to connect multiple peripherals to a computer, as if each had its own direct connection. One peripheral doesn't see another's communication, and there is only one computer. If a hub is externally powered (i.e. not just from the computer's USB port) it will power the peripherals even if the computer is off.

Sometimes there are devices that can use GPS data through an NMEA 0183 port which aren't obvious. My Furuno NAVTEX uses the position to select the nearest transmitter station, although I prefer to manually select it.

Greg

Clearly the price point interests me. I was looking over the various converters and rs485 are half the price of rs422 I think due to quantity of production as it supercedes rs422.

Since I have a way of getting my radio and gps communicating, I dont want to throw away too much extra money testing uncertainties. I got two delay relay boards and a rs485 converter for the price of one rs422 converter, so to me its a value added deal.

Yes, I read up on the usb, they do make a usb sharing hub but it simply seems to switch uptream ports, not really sharing them.

Speaking about robustness, I modified a UPS for PC's to run continuously by adding an internal fan and disabling its beeper. I then power my computer nav system completely from that UPS. I created a little wooden on-off remote switch for it next to the helm. Press a little button and it boots up.
Album link, I did this in 2013 and works good still.

https://goo.gl/photos/GfuN81JVot8J9iJKA

So its isolated from shore power, but could of course be plugged in direct to that or the gen. I thought it a good idea to run the stuff off the battery. I got the Minuteman UPS for free from my brothers son. I tend to hold on to lots of stuff and find uses for it but my garage is getting overloaded.

[CarinaPDX]

If you are not using a laptop with its internal battery to keep it up then using an inverter, or a UPS (inverter with some features), is a good plan. And free is a very good price. Using the ship's battery instead of the small motorcycle batteries that are normally inside a UPS makes sense, as long as it can't run down the starter battery.

Greg

[sdowney717]

Originally Posted by CarinaPDX

If you are not using a laptop with its internal battery to keep it up then using an inverter, or a UPS (inverter with some features), is a good plan. And free is a very good price. Using the ship's battery instead of the small motorcycle batteries that are normally inside a UPS makes sense, as long as it can't run down the starter battery.

Greg

yes, it cant run down. I have 2 group 27 12v Duracell marine deep cycles paralleled for house.
The starter is a group 31 and starts both engines.

They are interconnectable with two 3 way switches.
It gets a little complex, but any of the 3 can be disconnected or all turned off.

Port alternator charges the start battery, starboard the house bank.
I have a combining relay, just a continuous duty solenoid joining starter to house thru a manual switch and two diodes (preventing backfeeding power) in the ignition circuit also activates the solenoid when ignition turns on, (manual switch in series) so its nice to have two 12si 80 amp alternators share the load.
Alternators are fused to 80 amps, and directly connected to the battery post on each switch, so they can not be disconnected by spinning the rotary switches.

In my setup, before I did that, the house alternator would be overloaded by drained house batteries, and the start alternator just loafing. I can see the effects in the ammeter when I turn the switch on, the load is shared, one drops down, and other ammeter ramps up.

Another advantage besides lightening the load on the alternators, is this gives me a starting boost, at crank all 3 batteries are used to crank up the engines since when ignition comes on, the combining solenoid activates joining starter to house.

When engines are off, combining relay disconnects separating starter from house..

Alternators are the single wire 12si model. It just works great for me. Engines have to be slightly revved up to turn them on. Yes I know all the info about remote regulation, but I dont need it, as I said it works great. My wires are large enough, I have little voltage drop.

Before I did this setup, if I ran down house low, the alternator could burn up a belt and get hot, now by sharing the loads, never have any of that anymore. House batteries get more juice and recharge quicker.

I had people telling me it would not work, but they were wrong.

[barnakiel]

Laptops as onboard navigation devices are very poor choice.


Their weak point is zero waterproofing.
They nearly always require step-up chargers.

They have relatively short cable-less running time.

They have poor screens to read in stronger ambient light.



You are way safer using a smartphone or a tablet.


Even cheap tablets today will run 10-20 hours on one charge and many are near splash-proof with only some minimal mods (like a piece of masking tape over the usb port).


Let alone half the price per equivalent unit.


Cheers,

b.

[sdowney717]

Originally Posted by barnakiel

Laptops as onboard navigation devices are very poor choice.


Their weak point is zero waterproofing.
They nearly always require step-up chargers.

They have relatively short cable-less running time.

They have poor screens to read in stronger ambient light.



You are way safer using a smartphone or a tablet.


Even cheap tablets today will run 10-20 hours on one charge and many are near splash-proof with only some minimal mods (like a piece of masking tape over the usb port).


Let alone half the price per equivalent unit.


Cheers,

b.

I agree, glad I dont have one.
I have a PC ATX motherboard, and its easy to upgrade. Stashed away in a dry area.
A future upgrade will be a SSD in a nvme style.

Since screen is in main salon, it is shaded from the sun so can be easily read.

I have a galaxy Note8 runs opencpn as a backup. I have yet to have to use it for that.

It is really nice to have a dual helm boat. I almost never use the upper helm.

[sdowney717]

Updating my results. I bought the little circuit delay board and it works well.
GPS data always shows up on the radio screen. GPS wired up with terminal strip.
Board is set for about 5 second delay from seller. Takes many turns to change it.
I opened radio and attached a wire inside to send out a + 12v wire to turn the board on when the radio is turned on by the volume switch.

Plus a short video turning on the radio , the red light comes on first, the the blue is the delay on for the GPS. Not sure if you can see it though as it is not in a shared album.

https://photos.app.goo.gl/NFeJQ4m23s3P6vJo9

Other thing, this Cobra radio may have a very small continuous DC power draw even when off, I may need to put my ammeter on it and see. Which will make me want to use a 15 amp circuit breaker switch with a red handle which I have, but need to find a place to put it if I do that.

AND, this GPS up on the flybridge near my TV antenna, when on, ruins VHF TV reception for the channel 13... but UHF is not affected. Not a big deal. I was surprised the GPS emits vhf frequency interference. The TV antenna and the GPS are at the same height about 5 feet apart.