ICOM M802 GPS Connector???

[Russ]

Re my hook up.
ICOM suggested tapping into the green and white wires ( Data + and -)of the USB connector attached to the GSP Puck with the ICOM BNC cable from the radio.
That left the red/black power connections for the GPS getting power from the laptop.

[CarinaPDX]

I just remembered: Globalstar did ship a version with a PS/2 connector for "RS-232" connection, which presumably is what you have.

Both the GPS and the M802 default to 4800 baud; mismatched baud rates are one common source of difficulties.

I assume you have provided 5VDC power to the module; 12V would not be appropriate. Again, just checking.

In most cases GPS receivers that output in "RS-232" actually output 0/5V or even 0/3.3V (depending on the power provided) TTL in the same data format as RS-232/RS-422. This 0/5V signal should inter-operate with the RS-422 interface in the M802, which is also 0/5V. The 0/3.3V modules may not work (a problem I am dealing with now for a different GPS receiver) but as long as you are providing 5VDC power this won't happen.

You might check the wiring: the TX out from the GPS (green wire) goes to the central conductor in the BNC, and the shield of the BNC connects to the ground of the GPS (black wire). The red wire connects to 5VDC. The RX (white wire) won't be used with the M802; hook it up to a computer to change configurations if you are going to do that.

Greg

[Edit: you responded while I was writing. You definitely wired it wrong. Look at my last paragraph.]

[CarinaPDX]

Instead of using your laptop for power consider wiring in a dedicated power supply. I have good luck with these, also available from multiple flea-bay stores:

https://www.aliexpress.com/item/33042776274.html

Greg

[Russ]

Thanks Keep ya posted Russ

[Russ]

Carina

I tried all your suggestions and ICOM ideas. Nada

I confirmed I have nema GGA sentences, 4800 baud rate and 5 vdc. Laptop works with all three GPS receivers but not the 802. Russ

[CarinaPDX]

How are you getting it into the laptop? USB? Serial? Serial to USB adapter?

Greg

[Russ]

I have a usb male/female extension. So i go from GPS USB male to the extension female and then the extension's male into the laptop.

I used the extension just to avoid damaging the wiring of the GPS unit.

Any way I tapped into the USB extension's wiring and connected green, white or black to the ICOM BNC connector. in various combinations. I've tried all variations both with the green /white wires from the GPS intact or cut and just used as a feed from GPS receiver. I tried black and white ad green as ground and the opposite.

My old Trimble puts out to a R232 serial connector with a UBS convertor, even that doesn't work.
Next idea is to sacrifice one GPS receiver and wire direct to it (Green/White) and just leave Red/Black for the 5 vdc power needs of GPS receiver.
I haven't quit yet. ICOM tech very kind but no ideas.

[GILow]

This needs something clarified.

As far as I can tell, you are using the USB version of the puck? Is this correct? Not the PS2 version?

If so, it is not going to work. The USB versions need chipset drivers to get them talking.

[CarinaPDX]

Yes, GILow is right that it won't work, at least as is. You have a USB version of the puck. What this means is that the module interface is configured for the USB protocol, and needs the other end to negotiate a USB connection. The M802 has an NMEA interface, which is RS-422 with the traditional serial interface - a completely different protocol. The good news is that both are 0-5V signals so no damage should occur, but it isn't going to work for the Icom M802.

Inside the puck is a SirfStar IV GPS module, which is capable of providing USB or a TTL serial interface. I think it might use the same data wires for either, depending on the configuration, as opposed to the contemporary uBlox 8 module which has dedicated data connections for each protocol. It doesn't really matter as you are not going to be reconfiguring the puck, if for no other reason than you have other devices that need the USB interface.

These pucks are so cheap that you should just buy a new one with the right interface configured. I can help with that if you like (it is easy to order the wrong configuration, and big savings can be had by shopping in the right places). Let me know and we can pursue this.

Greg

[Russ]

Great info.
For clarity, I have tried a Trimble Navtrac putting out data to a serial R232 with USB convertor, a Quescan, u-blox based puck and a Global Star BU-353 S4. ( These two are USB based) The last two, of course, have had appropriate drivers installed on the laptop.
I'm all ears and willing to buy a compatible device.
Just lead me on please. thanks Russ

[Russ]

PS I believe the chipset drivers are what is supplied on the compact disc that came with each GPS unit.

Thanks Again Russ

[CarinaPDX]

Most GPS modules that support non-USB serial out use Prolific, or Prolific-compatible, serial drivers. Most modern OSes have the relevant drivers built in or automatically downloaded from the OS vendor as needed. You really shouldn't need the CDs. Anyway, best practice is to download the drivers in order to get the latest version if the OS doesn't manage it.

Some questions:

Do you want a puck format, or an exterior "mushroom" style case with a threaded mount?

Do you want GPS, GPS+GLONASS, GPS+GLONASS+BeiDou, or perhaps GPS+GLONASS+Galileo (increasing cost from roughly $10 to $30)? It is best to get the module pre-configured, although it would be possible to change the configuration later using your serial-USB adapter cable and appropriate software, if the module came with flash memory (an option) to store the new config. Better to not go down that road...

Almost all of the "RS-232" receivers use 5VDC. I made the mistake of ordering one that used a wide voltage range, including 12VDC. I had assumed that the assembler had added a 5V power supply module inside the case, but apparently they used a 3.3V power supply (the GPS module can use either); the result is that the output is 0-3.3V, not 0-5V, and it isn't enough for the data to be recognized by my Furuno MFD's interface. Grrrr. Now I have to add an external level shifter, which needs its own 5V supply, so my simplification has turned into a kludge. Best to stick with a 5V unit and add the 5V supply I linked to above.

The radio expects a 4800 baud signal, which is the NMEA 0183 standard. Most multi-system modules are set to 9600 baud, in part to handle the extra info with so many satellites tracked. Not only will it be necessary to buy one configured to 4800 baud, it might be a good idea to not go with a 3-GNSS receiver as it may be too much data for the baud rate. This would argue for a uBlox 7 GPS+GLONASS or even a GPS-only receiver. There is not any significant difference in accuracy for the multiple-GNSS systems - it is more an issue of redundancy.

How fast do you need this? The best deals will come direct from China, and could take a month or more. Personally I have been satisfied with buying from TopGNSS on aliexpress.com where possible.

Greg

[CarinaPDX]

I mis-wrote. The Prolific chip converts the serial to USB, so the drivers in the computer handle the serial interface over the USB connection. You will probably never need to know that, however.

I had another thought: because uBlox 8 modules have separate data lines for each supported interface protocol it is possible to have both USB and serial interfaces available and active. Some GPS receivers offer cabling that has both USB and serial connections. Perhaps that would be of interest to you?

Greg

[CarinaPDX]

I'm clearly not having a good day: the GPS units with both DE9 and USB connectors are just using the USB as a way of getting 5V into the receiver, and don't support USB data. So you will need to get an RS-232 unit, with either an internal or external 5V power supply.

When you decide what you want I can make some recommendations.

Greg

[GILow]

FWIW, I found a MR-350PS4 online for a very good price. I haven’t had a chance to test it yet but a few people have reported they work with the Icom M802.